Resonance suppression control circuit and testing system employing same, and method of designing resonance suppression control circuit

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First Claim
1. A resonance suppression control circuit which, establishing a physical system having a plurality of at least two vibration modes configured by connecting an electric motor and a test piece by a shaft, suppresses resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor,wherein the resonance suppression control circuit comprises a controller designed by way of a control system design method designated as μ
 design method using a generalized plant which includes a nominal model imitating input/output characteristics of the control target from an input of the electric motor until shaft torque of the shaft, and a structured perturbation relative to the generalized plant,wherein the nominal model defines one among the plurality of vibration modes as a suppression target, and is represented by the product of a suppression target vibration mode transfer function having a vibration mode of the suppression target, and a highorder vibration mode transfer function having a vibration mode which is higher order than the vibration mode of the suppression target, andwherein the structured perturbation includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function.
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Abstract
A resonance suppression control circuit provides operation stable for variations with a low order mode of vibration and suppressing spillover due to high order mode of vibration. This circuit controls a physical system having two or more modes of vibration, and suppresses resonance in a lowest order mode of vibration from among the plurality of modes. The circuit has a controller designed by a μ design method, using a generalized plant with nominal model, and structured perturbation to the generalized plant. The nominal model is represented by the product of a low order vibration mode transfer function having the low order mode of vibration to be suppressed, and a high order vibration mode transfer function having a high order mode of vibration. The structured perturbation includes a first parameter perturbation term which imparts a multiplicative error to a spring constant included in the vibration mode transfer function being suppressed.
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Engine testing system using torque controller designed by μsynthesis method  
Patent #
US 6,768,940 B2
Filed 10/10/2002

Current Assignee
Kabushiki Kaisha Meidensha

Sponsoring Entity
Kabushiki Kaisha Meidensha

Engine testing system using torque controller designed by musynthesis method  
Patent #
US 20030088345A1
Filed 10/10/2002

Current Assignee
Kabushiki Kaisha Meidensha

Sponsoring Entity
Kabushiki Kaisha Meidensha

TESTING SYSTEM AND METHOD FOR AUTOMOTIVE COMPONENT USING DYNAMOMETER  
Patent #
US 20020091471A1
Filed 01/09/2002

Current Assignee
Kabushiki Kaisha Meidensha

Sponsoring Entity
Kabushiki Kaisha Meidensha

Testing system and method for automotive component using dynamometer  
Patent #
US 6,434,454 B1
Filed 01/09/2002

Current Assignee
Kabushiki Kaisha Meidensha

Sponsoring Entity
Kabushiki Kaisha Meidensha

DRIVETRAIN TESTING SYSTEM  
Patent #
US 20150013443A1
Filed 12/07/2012

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Meidensha Corporation

Sponsoring Entity
Meidensha Corporation

Drivetrain testing system  
Patent #
US 9,207,149 B2
Filed 12/07/2012

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Meidensha Corporation

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Meidensha Corporation

Torque Command Generation Device  
Patent #
US 20160109328A1
Filed 04/21/2014

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Meidensha Corporation

Sponsoring Entity
Meidensha Corporation

Method for damping vibrations while testing a drivetrain having at least one shaft  
Patent #
US 9,632,007 B2
Filed 03/01/2013

Current Assignee
Kristl Seibt Co. Gesellschaft M.B.H.

Sponsoring Entity
Kristl Seibt Co. Gesellschaft M.B.H.

Torque command generation device  
Patent #
US 9,689,774 B2
Filed 04/21/2014

Current Assignee
Meidensha Corporation

Sponsoring Entity
Meidensha Corporation

Dynamometer system  
Patent #
US 9,739,687 B2
Filed 10/06/2014

Current Assignee
Meidensha Corporation

Sponsoring Entity
Meidensha Corporation

20 Claims
 1. A resonance suppression control circuit which, establishing a physical system having a plurality of at least two vibration modes configured by connecting an electric motor and a test piece by a shaft, suppresses resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor,
wherein the resonance suppression control circuit comprises a controller designed by way of a control system design method designated as μ  design method using a generalized plant which includes a nominal model imitating input/output characteristics of the control target from an input of the electric motor until shaft torque of the shaft, and a structured perturbation relative to the generalized plant,
wherein the nominal model defines one among the plurality of vibration modes as a suppression target, and is represented by the product of a suppression target vibration mode transfer function having a vibration mode of the suppression target, and a highorder vibration mode transfer function having a vibration mode which is higher order than the vibration mode of the suppression target, and wherein the structured perturbation includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function.  View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
 design method using a generalized plant which includes a nominal model imitating input/output characteristics of the control target from an input of the electric motor until shaft torque of the shaft, and a structured perturbation relative to the generalized plant,
 20. A method of designing a resonance suppression control circuit which, establishing a physical system configured by connecting an electric motor and a test piece by a shaft, and having a plurality of at least two vibration modes as a control target, suppresses resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor, the method comprising:
defining one among the plurality of vibration modes as a suppression target, and stipulating a generalized plant which includes nominal model imitating input/output characteristics of the control target from an input to the electric motor until a shaft torque of the shaft, by a product of a suppression target vibration mode transfer function having a vibration mode of the suppression target, and a highorder vibration mode transfer function having a vibration mode which is higher order than the vibration mode of the suppression target; stipulating a structured perturbation which includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function in the generalized plant; and designing the resonance suppression control circuit by way of a suppression system design method designated as pt design method using the stipulated generalized plant and structured perturbation.
1 Specification
The present invention relates to a resonance suppression control circuit with a physical system having a plurality of vibration modes as a control target which suppresses resonance in at least one vibration mode among this plurality of vibration modes, a test system using this resonance suppression control circuit, and a method of designing this resonance suppression control circuit.
Drive train refers to an abbreviation for a plurality of devices for transferring energy generated by an engine to drive wheels, and is configured by an engine, clutch, transmission, drive shaft, propeller shaft, differential gear, drive wheels, etc. In performance evaluation testing of a drive train, the durability performance, quality, etc. thereof are evaluated by actually continuously driving the transmission by the engine. In recent years, as a system which performs such testing of drive trains, a system has been presented which causes the drive torque inputted on a workpiece to be generated by a motor instead of an actual engine (for example, refer to Patent Document 1).
Since periodic torque fluctuation arises due to the combustion cycle of each cylinder in the actual engine, with the system illustrated in the abovementioned Patent Document 1, the drive torque generated by the motor is pseudo fluctuated by summing the alternating current component by a sine wave in the direct current component for generating constant drive torque.
However, since a unique vibration mode characterized by a prescribed resonance frequency exists in the abovementioned such test system configured by joining the test piece and a dynamometer by a shaft, if causing the torque current command signal to the motor to fluctuate periodically, when the frequency thereof passes through the unique resonance frequency in the test system, it may induce resonance vibration. Therefore, with the test system of Patent Document 2, the occurrence of such resonance is suppressed by generating a torque current command signal using a resonance suppression control circuit designed using a control system design method such as H∞ control or μ design.
 Patent Document 1: Japanese Unexamined Patent Application, Publication No. 200271520
 Patent Document 2: PCT International Publication No. WO2015/136626
Herein, there are several problems in the resonance suppression control circuit shown in Cited Document 2. First, the resonance frequency of a vibration mode serving as the suppression target somewhat fluctuates depending on various factors; however, the resonance suppression control circuit of Patent Document 2 does not consider the above such fluctuation in resonance frequency in the design stage thereof. Herein, as a factor inducing fluctuation in the resonance frequency serving as the suppression target, a case of the mechanical characteristic thereof varying from that assumed at the design stage due to the test piece being exchanged; a case of the inertial moment thereof varying due to the state of the test piece (e.g., case of establishing the drive train of an AT vehicle including a torque converter as the test piece, existence/lack of a lockup function thereof); etc. can be exemplified. For this reason, in the resonance suppression control circuit of Patent Document 2, the control may become unstable due to the above such fluctuation in resonance frequency.
Second, the resonance suppression control circuit shown in Patent Document 2 is designed with a model approximating a physical system by a socalled twoinertia system configured by linking two rigid bodies by a spring as the nominal model; however, this twoinertia system only has one vibration mode theoretically. However, since a plurality of vibration modes exist in the actual physical system, when applying the resonance suppression control circuit designed with such a two inertial system as the nominal model to an actual physical system, spillover in which control becomes unstable may occur by the influence of a plurality of highorder resonance modes which were ignored during design.
However, in order to solve the first problem, it has been considered to define a perturbation term relative to a parameter affecting the variation in resonance frequency among the plurality of parameters constituting the nominal mode, and to construct a resonance suppression control circuit in which robust stability relative to such variation in resonance frequency is assured by the μ design method. In addition, in order to solve the second problem, it has been considered to expand the nominal model to a multiinertia system of at least three having a plurality of vibration modes. However, it has been considered difficult to solve these two problems at the same time. In other words, with the twoinertia system defined in Patent Document 2, since the resonance frequency of the vibration mode varies depending on spring stiffness or moment of inertia, it is relatively easy to introduce a perturbation term made assuming the variation in resonance frequency to solve the first problem. However, if expanding the nominal model to a multiinertial system of at least three in order to solve the second problem, since the variation in resonance frequency of each vibration mode has a correlation with many parameters constituting the multiinertial system, the introduction of a perturbation term made assuming the variation in the resonance frequency is not easy, and thus solving the first problem becomes difficult.
The present invention was made taking account of the above such problems, and has an object of providing a resonance suppression control circuit which can suppress spillover due to highorder vibration mode, at the same time as providing stable operation with respect to variation in a loworder vibration mode.
A resonance suppression control circuit (for example, the resonance suppression control circuit 5 described later) according to a first aspect of the present invention which, establishing a physical system having a plurality of at least two vibration modes configured by connecting an electric motor (for example, the drive motor 2 described later) and a test piece (for example, the test piece W described later) by a shaft, suppresses resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor, the resonance suppression control circuit including a controller (for example, the Gc1(s), Gc2(s) described later) designed by way of a control system design method designated as μ design method using a generalized plant (for example, the generalized plant P1 to P12 described later) which includes a nominal model (for example, the nominal model N1 to N12 described later) imitating input/output characteristics of the control target from an input of the electric motor until shaft torque of the shaft, and a structured perturbation (for example, the structured perturbation Δ described later) relative to the generalized plant, in which the nominal model defines one among the plurality of vibration modes (for example, the loworder vibration mode R1 described later) as a suppression target, and is represented by the product of a suppression target vibration mode transfer function (for example, the loworder vibration mode transfer functions M1(s), M2(s) described later) having a vibration mode (for example, the loworder vibration mode R1 described later) of the suppression target, and a highorder vibration mode transfer function (for example, the highorder vibration mode transfer function Hx(s) described later) having a vibration mode (for example, the highorder vibration modes R2, R3 described later) which is higher order than the vibration mode of the suppression target, and in which the structured perturbation includes at least one perturbation term (for example, the first parameter perturbation term 61 and second parameter perturbation term 62 described later) relative to a parameter (for example, the spring constants K1, K2, unit moment of inertia J, first moment of inertia J1 and second moment of inertia J2 described later) included in the suppression target vibration mode transfer function.
According to a second aspect of the present invention, in this case, it is preferable for a transfer function (for example, the loworder vibration mode transfer function M1(s) described later) from an input to an inertia field until an output of a shaft element in a onedegreeoffreedom vibration system configured by connecting the inertia field having a predetermined moment of inertia (for example, the unit moment of inertia J described later) and a solid wall by the shaft element having a predetermined spring constant (for example, the spring constant K1 described later) and damping constant (for example, the damping constant C1 described later), to be used in the suppression target vibration mode transfer function.
According to a third aspect of the present invention, in this case, it is preferable for the structured perturbation to include a perturbation term (for example, the first parameter perturbation term δ1 described later) relative to the spring constant (for example, the spring constant K1 described later).
According to a fourth aspect of the present invention, in this case, it is preferable for the structured perturbation to include a perturbation term (for example, the first parameter perturbation term δ1 described later) relative to the moment of inertia (for example, the unit moment of inertia J described later).
According to a fifth aspect of the present invention, in this case, it is preferable, when defining a pole of the suppression target vibration mode transfer function as “p_{R}” and defining a complex conjugate thereof as “p_{R}*”, for the spring constant K1, the damping constant C1 and the suppression target vibration mode transfer function M1(s) to be represented by Formula (1) below.
According to a sixth aspect of the present invention, in this case, it is preferable for a transfer function (for example, the loworder vibration mode transfer function M2(s) described later) from an input to a first inertia field until an output of a shaft element in a two inertia system configured by connecting the first inertia field having a predetermined first moment of inertia (for example, the first moment of inertia J1 described later) and a second inertia field having a predetermined second moment of inertia (for example, the second moment of inertia J2 described later) by the shaft element having a predetermined spring constant (for example, the spring constant K2 described later) and damping constant (for example, the damping constant C2 described later), to be used in the suppression target vibration mode transfer function.
According to a seventh aspect of the present invention, in this case, it is preferable for the structured perturbation to include a perturbation term (for example, the first parameter perturbation term δ1 described later) relative to the spring constant (for example, the spring constant K2 described later).
According to an eighth aspect of the present invention, in this case, it is preferable for the structured perturbation to include a perturbation term (for example, the first parameter perturbation term δ1 described later) relative to the second moment of inertia (for example, the second moment of inertia J2 described later).
According to a ninth aspect of the present invention, in this case, it is preferable for the structured perturbation to include a perturbation term (for example, the first parameter perturbation term δ1 described later) relative to the first moment of inertia (for example, the first moment of inertia J2 described later).
According to a tenth aspect of the present invention, in this case, it is preferable for the structured perturbation to include a perturbation term (for example, the first parameter perturbation term δ1 described later) relative to the spring constant (for example, the spring constant K2 described later) and a perturbation term (for example, the second parameter perturbation term δ2 described later) relative to the second moment of inertia (for example, the second moment of inertia J2 described later).
According to an eleventh aspect of the present invention, in this case, it is preferable, when defining a pole of the suppression target vibration mode transfer function as “pR”, defining a complex conjugate thereof as “pR*”, defining the first moment of inertia as “J1” and defining the second moment of inertia as “J2”, for the spring constant K2, the damping constant C2 and the suppression target vibration mode transfer function M2(s) to be represented by Formula (2) below.
According to a twelfth aspect of the present invention, in this case, it is preferable for the highorder vibration mode transfer function to be identified so that a transfer function obtained by multiplying this highorder vibration mode transfer function and the suppression target vibration mode transfer function matches a transfer function from an input to the electric motor of the suppression target until a shaft torque of the shaft.
A test system (for example, the test system S described later) according to a thirteenth aspect of the present invention includes: an electric motor (for example, the drive motor 2 described later) which is connected with a test piece (for example, the test piece W described later) via a shaft (for example, the connecting shaft S1 described later); a shaft torque meter (for example, the shaft torque meter 6 described later) which detects shaft torque generated at the shaft; an inverter (for example, the inverter 3 described later) which supplies electric power to the electric motor; and a resonance suppression control circuit (for example, the resonance suppression control circuit 5 described later) which generates, using a command signal relative to generated torque of the electric motor and a detection signal of the shaft torque meter, a torque current command signal to the electric motor so that resonance of the shaft is suppressed, and then inputs the torque current command signal to the inverter, in which a resonance suppression control circuit as described in any one of the first to twelfth aspects is used as the resonance suppression control circuit.
A resonance suppression control circuit (for example, the resonance suppression control circuit 5 described later) according to a fourteenth aspect of the present invention has a function of establishing a physical system configured by connecting an electric motor (for example, the drive motor 2 described later) and a test piece (for example, the test piece W described later) by a shaft (for example, the connecting shaft S1 described later), and having a plurality of at least two vibration modes as a control target, and suppressing resonance in at least one vibration mode among the plurality of vibration modes by applying an input to the electric motor. A method of designing a resonance suppression control circuit having such functions includes: defining one among the plurality of vibration modes as a suppression target, and stipulating a generalized plant (for example, the generalized plant P1 to P12 described later) which includes nominal model (for example, the nominal model N1 to N12 described later) imitating input/output characteristics of the control target from an input to the electric motor until a shaft torque of the shaft, by a product of a suppression target vibration mode transfer function (for example, the loworder vibration mode transfer function M1(s), M2(s) described later) having a vibration mode of the suppression target, and a highorder vibration mode transfer function (for example, the highorder vibration mode transfer function Hx(s) described later) having a vibration mode which is higher order than the vibration mode of the suppression target; stipulating a structured perturbation (for example, the structured perturbation Δ described later) which includes at least one perturbation term (for example, the first parameter perturbation term δ1 and second parameter perturbation term δ2 described later) relative to a parameter included in the suppression target vibration mode transfer function in the generalized plant; and designing the resonance suppression control circuit by way of a suppression system design method designated as μ design method using the stipulated generalized plant and structured perturbation.
The present invention represents the nominal model which imitates the input/output characteristics from an input to the electric motor until the output of the shaft torque in the control target having a plurality of vibration modes, by the product of the suppression target vibration mode transfer function having the vibration mode serving as the suppression target, and the highorder vibration mode transfer function having a vibration mode of higher order than this suppression target vibration mode. Then, the resonance suppression control circuit is designed by the μ design method using the generalized plant having the nominal model encompassing both the suppression target vibration mode and highorder vibration mode in this way, and the structured perturbation relative to this generalized plant. According to the resonance suppression control circuit of the present invention, it is thereby possible to suppress spillover due to the highorder vibration mode. In addition, the present invention, upon separating the nominal model into the suppression target vibration mode transfer function and highorder vibration mode transfer function in the aforementioned way, includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function encompassing the suppress target vibration mode among these two transfer functions, in the structured perturbation. By introducing such a perturbation term, according to the present invention, it is possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
Herein, the significance of separating the nominal model into two transfer functions will be explained. In general, the input/output characteristics of a physical system serving as the control target can be expressed by a simple transfer function so long as using a known system identification method. However, in the case of the control target having a plurality of vibration modes, the function form of the transfer function identified in this way has a higher number of orders, and the correlation between the plurality of parameters constituting the transfer function and the resonance frequency of the suppression target vibration mode becomes complex. For this reason, it is difficult to extract only a parameter having a correlation with this resonance frequency and set the perturbation term to this parameter, for considering the variation in resonance frequency of the suppression target vibration modes. In contrast, by expressing the nominal model in the abovementioned way by the product of the suppression target vibration mode transfer function and the highorder vibration mode transfer function, since the present invention can express the function form of the suppression target vibration mode transfer function in a simple form of low order, it is easy to extract a parameter having a correlation with the resonance frequency of the suppression target vibration mode, and thus setting of the perturbation term becomes easy. According to the resonance suppression control circuit of the present invention, it is thereby also possible to suppress spillover due to highorder vibration mode, while at the same time providing operation that is stable with respect to variations in resonance frequency of a loworder mode of vibration.
The present invention uses a transfer function from an input to the inertia field to the output of the shaft element in a onedegreeoffreedom vibration system configured by connecting the inertia field and a solid wall by a shaft element having a predetermined spring constant and damping constant, as the suppression target vibration mode transfer function. Since it is thereby possible to express the suppression target vibration mode transfer function by a simple function form of low order, setting of a perturbation term for considering the variation in resonance frequency of the suppression target vibration mode serving as the suppression target can be done easily.
The magnitude of the resonance frequency in the aforementioned onedegreeoffreedom vibration system has a correlation with the magnitude of the spring constant, and thus the present invention sets the perturbation term relative to such a spring constant. It is thereby possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
The magnitude of the resonance frequency in the aforementioned onedegreeoffreedom vibration system has a correlation with the magnitude of the moment of inertia, and thus the present invention sets the perturbation term relative to such a moment of inertia. It is thereby possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
The present invention defines the pole of the suppression target vibration mode transfer function corresponding to the resonance point of the suppression target vibration mode as “pR”, and defines the complex conjugate thereof as “pR*”, and using these, configures the suppression target vibration mode transfer function M1(s), spring constant K1 and damping constant C1 as in Formula (1) above. By establishing the suppression target vibration mode transfer function as such a simple configuration, the present invention can easily set the perturbation term for considering the variation in resonance frequency of the suppress target vibration mode.
The present invention uses a transfer function from an input to the first inertia field until an output of the shaft element in a two inertia system configured by connecting the first inertia field and the second inertia field by the shaft element having a predetermined spring constant and damping constant, as the suppression target vibration mode transfer function. Since it is thereby possible to express the suppression target vibration mode transfer function by a simple function form of low order, setting of a perturbation term for considering the variation in resonance frequency of the suppression target vibration mode serving as the suppression target can be done easily.
The magnitude of the resonance frequency in the aforementioned two inertia system has a correlation with the magnitude of the spring constant, and thus the present invention sets the perturbation term relative to such a spring constant. It is thereby possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
The magnitude of the resonance frequency in the aforementioned two inertia system has a correlation with the magnitude of the second moment of inertia, and thus the present invention sets the perturbation term relative to such a second moment of inertia. It is thereby possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
The magnitude of the resonance frequency in the aforementioned two inertia system has a correlation with the magnitude of the first moment of inertia, and thus the present invention sets the perturbation term relative to such a first moment of inertia. It is thereby possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
The magnitude of the resonance frequency in the aforementioned two inertia system has a correlation with the magnitudes of both the spring constant and the second moment of inertia, and thus the present invention sets the perturbation term relative to each of this spring constant and second moment of inertia. It is thereby possible to construct a resonance suppression control circuit for which robust stability is ensured relative to variation in the resonance frequency of the suppression target vibration mode.
The present invention defines the pole of the suppression target vibration mode transfer function corresponding to the resonance point of the suppression target vibration mode as “pR”, defines the complex conjugate thereof as “pR*”, defines the first moment of inertia as “J1”, and further defines the second moment of inertia as “J2”, and using these, configures the suppression target vibration mode transfer function M2(s), spring constant K2 and damping constant C2 as in Formula (2) above. By establishing the suppression target vibration mode transfer function as such a simple configuration, the present invention can easily set the perturbation term for considering the variation in resonance frequency of the suppress target vibration mode.
The present invention identifies the highorder vibration mode transfer function so that a transfer function obtained by multiplying an unknown highorder vibration mode transfer function and a known suppression target vibration mode transfer function matches a measurable transfer function from an input to the electric motor until the shaft torque of the shaft in the control target. It is thereby possible to stipulate a nominal model which accurately imitates the input/output characteristic of the actual control target.
The present invention generates a torque current command signal relative to the electric motor using the resonance suppression control circuit of any one of the above (1) to (12), and inputs this to the inverter. It is thereby possible to also suppress the spillover due to the influence of highorder vibration mode while at the same time realizing stable control, even in a case of variations arising in the resonance frequency of the suppression target vibration mode of the test system due to the test piece being replaced or the state of the test piece changing.
The present invention expresses the nominal model imitating the input/output characteristics from an input to the electric motor until an output of the shaft torque in the control target having a plurality of vibration modes, by the product of the suppression target vibration mode transfer function having the vibration mode serving as the suppression target, and the highorder vibration mode transfer function having a vibration mode or higher order than this suppress target vibration mode. In addition, the present invention, upon separating the nominal model into the suppression target vibration mode transfer function and highorder vibration mode transfer function in the aforementioned way, includes at least one perturbation term relative to a parameter included in the suppression target vibration mode transfer function encompassing the suppress target vibration mode among these two transfer functions, in the structured perturbation. Then, the resonance suppression control circuit is designed by way of μ design using the generalized plant having such a nominal model, and the structured perturbation including the aforementioned such perturbation term. It is thereby possible to design a resonance suppression control circuit which can suppress spillover due to a highorder vibration mode, while at the same time providing stable operation with respect to variations in resonance frequency of the suppression target vibration mode.
Hereinafter, an embodiment of the present invention will be explained in detail while referencing the drawings.
The test system S includes a drive motor 2 which is connected with the test piece W by a connecting shaft S; an inverter 3 which supplies electric power to this drive motor 2; a shaft torque meter 6 which detects shaft torque generated at the connecting shaft S1; a resonance suppression control circuit 5 which generates a torque current command signal corresponding to a command related to torque generated by the drive motor 2; and a base torque command generation circuit 7 which generates a base torque command signal serving as the base of the abovementioned torque current command signal.
The output shaft of the drive motor 2 is connected via the connecting shaft S1 with the input shaft of the test piece W, and makes it possible to transfer the power from the drive motor 2 to the test piece W. In addition, at both ends of a drive shaft S2 corresponding to the output shaft of the test piece W, regenerative motors 8L, 8R which generate load on the test piece W are connected. It should be noted that, at the test piece W′ in
The base torque command generation circuit 7 uses the drive motor 2 to resemble an engine connected to the test piece W, which is the drive train of a vehicle, and generates a base torque command signal imitating the engine torque. The base torque command generation circuit 7 generates a base torque command signal by superimposing an AC signal of a predetermined excitation frequency imitating the torque pulsation included in engine torque, on the DC signal of a predetermined magnitude.
The resonance suppression control circuit 5 generates a torque current command signal based on the base torque command signal generated by the base torque command generation circuit 7 and the shaft torque detection signal inputted from the shaft torque meter 6, and inputs this to the inverter 3.
According to the above such configuration, the test system S causes a pseudoengine torque including fluctuations imitating the torque pulsations of the engine by the drive motor 2, and inputs this torque to the test piece W, whereby the durability performance, quality, etc. of this test piece W are evaluated.
Herein, the functions of the resonance suppression control circuit 5 will be explained. In the test system S, in the physical system configured by the inverter 3, drive motor, test piece W, connecting shaft S1 and shaft torque meter 6, a plurality of vibration modes of at least two (for example, refer to vibration modes R1, R2, R3, etc. in
As the resonance suppression control circuit 5 including the above such resonance suppression function, a circuit configured by installing to an electronic computer a controller designed by the robust control design method called the μ design method in a feedback control system such as that shown in
The feedback control system of
The generalized plant P establishes, as the control target, a physical system configured by the inverter 3, drive motor 2, connecting shaft S1, test piece W and shaft torque meter 6 of the test system S in
Referring back to
In the μ design method, a feedback control system in which the structured perturbation Δ is set relative to a closed loop system configured by the generalized plant P and controller K as shown in
Next, a resonance suppression control circuit of Example 1 and the design method thereof will be explained.
The generalized plant P1 of Example 1 is configured by combining a nominal model N1 imitating the I/O characteristic from the torque current command signal of the control target until the shaft torque detection signal of the shaft torque sensor, and the plurality of weighting functions Gw1(s) and Gw2(s).
The transfer function G(s) of the nominal model N1 defines the lowest order vibration mode among the plurality of vibration modes possessed by the control target as the suppression target in the aforementioned way, and is realized by the product (G(s)=Hx(s)×M1(s)) of a loworder vibration mode transfer function M1(s) having this loworder vibration mode, and a highorder vibration mode transfer function Hx(s) having a vibration mode of higher order than the loworder vibration mode of the suppression target.
In a onedegreeoffreedom vibration system configured by connecting an inertia field having the unit moment of inertia J (hereinafter, set as J=1, omitting illustration thereof, etc.) and a rigid wall by an axial element having a predetermined spring constant K1 and damping constant C1, a transfer function from the torque acting on the inertia field until the torque generated at the axial element, and having a pole corresponding to the vibration mode of the suppression target is used as the loworder vibration mode transfer function M1(s). More specifically, in the case of defining the pole of the transfer function M1(s) as “p_{R}”, and defining the complex conjugate thereof as “p_{R}*”, the spring constant K1, damping constant C1 and loworder vibration mode transfer function M1(s) are represented as in the following formula (3). In addition, this loworder vibration mode transfer function M1(s) is represented by the block B1 in the block diagram of
As the highorder vibration mode transfer function Hx(s), a transfer function having a plurality of vibration modes of higher order than the loworder vibration mode of the suppression target is used. More specifically, the highorder vibration mode transfer function Hx(s) is identified by measuring transfer functions from the torque current command signal of an actual control target until the shaft torque detection signal, and using a known system identification method, so that this and the product Hx(s)×M1(s) of the two transfer functions match.
It should be noted that, upon identifying the highorder vibration mode transfer function Hx(s) in the abovementioned way, the function form thereof is assumed by H1(s) or H2(s) shown in the following formula (4), for example. Herein, “b(s)” and “a(s)” in the following formula (4) are each polynomials of arbitrary orders with the highest order coefficient of 1. In addition, “g” in the following formula (4) is the highest order coefficient of a numerator polynomial, in the case of setting the highest order coefficient of a denominator polynomial of the transfer function G(s) of the nominal model N1 as 1. Each function of the denominator polynomial a(s) and numerator polynomial b(s) in the following formula (4), and the value of the highest order coefficient g are identified using the known system identification method as mentioned above, collectively with the value of the complex number p_{R }representing the pole of the transfer function M1(s). It should be noted that although a case setting the specific function form of the highorder vibration mode transfer function Hx(s) as H1(s) will be explained hereinafter, it is not limited thereto, and the function form of Hx(s) may be set as H2(s). It should be noted that, in the case of setting the function form as H1(s), there is an advantage in that the reproducibility of the nominal model N1 improves, and in the case of setting the function form as H2(s), there is an advantage in that operation and implementation become easier by the amount by which being a lower order compared to H1(s).
The first external input w1 is an input signal for evaluating the torque control error of the inverter, and the first control output z1 is an output signal for evaluating the shaft torque detection signal. To the nominal model N1, a value produced by summing the first external input w1 and the control input u outputted from the controller K is inputted. In addition, in the first control output z1, the output signal of the nominal model N1 is used. The vibration mode included in the nominal model N1 is excited by the first external input w1. In addition, by the vibration mode being evaluated by the first control output z1, the resonance suppression control circuit such that the vibration mode included in the nominal model N1 declines is obtained.
The second external input w2 is an input signal corresponding to the base torque command signal, and is inputted to the controller K as the first observation output y1. The second control output z2 is an output signal obtained by multiplying a predetermined second weighting function Gw2(s) by the control input u outputted from the controller K. The specific function form of this second weighting function Gw2(s) is set so that the highrange gain of the resonance suppression control circuit declines.
The third external input w3 is an input signal corresponding to the noise in relation to the shaft torque detection signal. The total of summing the third external input w3 and the output signal of the nominal model N1 is inputted to the controller K as the second observation output y2. The third control output z3 is an output signal obtained by multiplying a predetermined first weighting function Gw1(s) by the deviation between the control input outputted from the controller K and the second external input w2. The specific function form of this first weighting function Gw1(s) is set so as to have an integral characteristic in a lower range than the loworder vibration mode serving as the suppression target. It is thereby possible to cause the gain of the resonance suppression control circuit in a lower range than the loworder vibration mode of the suppression target to decline.
The fourth external input w4 and fourth control output z4 are I/O signals set relative to the nominal model N1 in order to evaluate the influence due to fluctuation in resonance frequency of the loworder vibration mode serving as the suppression target, among the various errors between the actual control target and the nominal model N1 (hereinafter referred to as “model error”). This fourth external input w4 and fourth control output z4 are set so as to apply multiplicative error to this spring constant K1, at the output terminal of the spring constant K1 having a correlation with the magnitude of the resonance frequency of the loworder vibration mode, among the plurality of parameters included in the loworder vibration mode transfer function M1(s) having the loworder vibration mode as shown in
In addition, in order to configure so that a resonance suppression control circuit is obtained that is robustly stable relative to the multiplicative error of the spring constant K1 which affects the variation directly on the resonance frequency of the loworder vibration mode, the first parameter perturbation term δ1 constituting one of the diagonal elements of the structured perturbation Δ is set between this fourth control output z4 and fourth external input w4 (refer to
The generalized plant P2 according to Example 2 has a configuration of the nominal model N2 which differs from the generalized plant P1 according to Example 1. More specifically, it differs in the point of the order of multiplying the highorder vibration mode transfer function Hx(s) and the loworder vibration mode transfer function M1(s) being opposite to the nominal model N1 according to Example 1, and the other configurations are the same. The resonance suppression control circuit of Example 2 is derived based on the μ design method using the generalized plant P2 in which structured perturbation Δ is stipulated in the above way.
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In contrast, according to the resonance suppress control circuit of Example 1 or Example 2, in both the nominal plant model (left side of
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The fourth external input w4 and fourth control output z4 are set so as to apply multiplicative error on the unit moment of inertia J (=1) having a correlation with the magnitude of resonance frequency of the loworder vibration mode, among the plurality of parameters included in the loworder vibration mode transfer function M1(s) having a loworder vibration mode as shown in
The generalized plant P4 according to Example 4 has a configuration of the nominal model N which differs from the generalized plant P3 according to Example 3. More specifically, it differs in the point of the order of multiplying the highorder vibration mode transfer function Hx(s) and the loworder vibration mode transfer function M1(s) being opposite the nominal model N3 according to Example 3, and the other configurations are the same. The resonance suppress control circuit of Example 4 is derived based on the μ design method using the generalized plant P4 in which structured perturbation Δ is stipulated in the above way.
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In the generalized plant P5 according to Example 5, the configuration of the nominal model N5 differs from the generalized plant P1 according to Example 1. The transfer function G(s) of the nominal model N5 is represented by the product (G(s)=Hx(s)×M2(s)) of the loworder vibration mode transfer function M2(s) having the loworder vibration mode R1 serving as the suppression target and the highorder vibration mode transfer function Hx(s) having vibration modes R2 and R3 which are higher order than this loworder vibration mode R1.
In the twodegrees of freedom vibration system configured by connecting a first inertia field having a predetermined first moment of inertia J1 and a second inertia field having a predetermined second moment of inertia J2 by a shaft element having a predetermined spring constant K2 and damping constant C2, a transfer function from the torque acting on the first inertia field until the torque generated at the shaft element having a pole corresponding to the loworder vibration mode R1 of the suppression target is used as the loworder vibration mode transfer function M2(s). More specifically, in the case of defining the pole of the transfer function M2(s) as “p_{R}”, and defining the complex conjugate thereof as “p_{R}*”, the spring constant K2, damping constant C2 and loworder vibration mode transfer function M2(s) are expressed as in the following formula (5). In addition, this loworder vibration mode transfer function M2(s) is represented by block B5 in the block diagram of
The highorder vibration mode transfer function Hx(s) is identified by specifying the function form thereof by H1(s) or H2(s) shown in formula (4) similarly to Example 1, and using a known system identification method similarly to Example 1, together with the value of the complex number p_{R }representing the pole of the transfer function M2(s).
In addition, the fourth external input w4 and fourth control output z4 are set so as to apply multiplicative error on this spring constant K2, at the output terminal of the spring constant K2 having a correlation with the magnitude of the resonance frequency of the loworder vibration mode, among the plurality of parameters included in the loworder vibration mode transfer function M2(s) having the loworder vibration mode as shown in
The generalized plant P6 according to Example 6 has a configuration of the nominal model N6 which differs from the generalized plant P5 according to Example 5. More specifically, it differs in the point of the order of multiplying the highorder vibration mode transfer function Hx(s) and loworder vibration mode transfer function M2(s) being opposite the nominal model N5 according to Example 5, and the other configurations are the same. The resonance suppression control circuit of Example 6 is derived based on the μ design method using the generalized plant P6 in which the structured perturbation Δ is stipulated in the above way.
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The fourth external input w4 and fourth control output z4 are set so as to apply multiplicative error on the second moment of inertia J2 having a correlation with the magnitude of resonance frequency of the loworder resonance mode, among the plurality of parameters included in the loworder vibration mode transfer function M2(s) having a loworder vibration mode as shown in
The generalized plant P8 according to Example 8 has a configuration of the nominal model N8 which differs from the generalized plant P7 according to Example 7. More specifically, it differs in the point of the order of multiplying the highorder vibration mode transfer function Hx(s) and the loworder vibration mode transfer function M2(s) being opposite the nominal model N7 according to Example 7, and the other configurations are the same. The resonance suppression control circuit of Example 8 is derived based on the μ design method using the generalized plant P8 in which structured perturbation Δ is stipulated in the above way.
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The fourth external input w4 and fourth control output z4 are set so as to apply multiplicative error to the first moment of inertia J1 having a correlation with the magnitude of the resonance frequency of the loworder vibration mode, among the plurality of parameters included in the loworder vibration mode transfer function M2(s) having a loworder vibration mode as shown in
The generalized plant P10 according to Example 10 has a configuration of the nominal model N10 which differs from the generalized plant P9 according to Example 9. More specifically, it differs in the point of the order of multiplying the highorder vibration mode transfer function Hx(s) and the loworder vibration mode transfer function M2(s) being opposite to the nominal model N9 according to Example 9, and the other configurations are the same. The resonance suppression control circuit of Example 10 is derived based on the μ design method using the generalized plant P10 in which structured perturbation Δ is stipulated in the above way.
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Among the plurality of parameters included in the loworder vibration mode transfer function M2(s) having loworder vibration mode, the fifth external input w5 and fifth control output z5 are set so as to apply multiplicative error to this second moment of inertia J2, in the output terminal of the second moment of inertia having a correlation with the magnitude of the resonance frequency of the loworder vibration mode. In addition, in order to configure so that a resonance suppression control circuit is obtained which is robustly stable relative to multiplicative error in the second moment of inertia J2 which affects the fluctuation directly on the resonance frequency of the loworder vibration mode, the second parameter perturbation term δ2 constituting one of the diagonal elements of the structured perturbation Δ is set between this fifth control output z5 and fifth external input w5. The resonance suppression control circuit of Example 11 is derived based on the μ design method using the generalized plant P11 in which structured perturbation Δ is stipulated in the above way.
The generalized plant P12 according to Example 12 has a configuration of the nominal model N12 which differs from the generalized plant P11 according to Example 11. More specifically, it differs in the point of the order of multiplying the highorder vibration mode transfer function Hx(s) and the loworder vibration mode transfer function M2(s) being opposite to the nominal model N1 according to Example 11, and the other configurations are the same. The resonance suppression control circuit of Example 12 is derived based on the μ design method using the generalized plant P12 in which structured perturbation Δ is stipulated in the above way.
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Although an embodiment of the present invention has been explained above, the present invention is not to be limited thereto. The configurations of each part may be modified as appropriate within the scope of the gist of the present invention. For example, in the abovementioned embodiment, a case of applying the resonance suppression control circuits of Examples 1 to 12 to a drive train bench system establishing the drive train of a vehicle as the test piece was explained; however, the present invention is not to be limited thereto. In other words, the resonance suppression control circuits of Examples 1 to 12 may be applied to a socalled engine bench system which establishes the engine of a vehicle as the test piece.

 S test system
 S1 connecting shaft (shaft)
 W, W′ test piece
 2 drive motor (electric motor)
 5 resonance suppression control circuit
 6 shaft torque meter
 R1 loworder vibration mode
 R2, R3 highorder vibration mode
 P1˜P12 generalized plant
 N1˜N12 nominal model
 M1(s), M2(s) loworder vibration mode transfer function (suppression target vibration mode transfer function)
 Hx(s) highorder vibration mode transfer function
 Gc1(s), Gc2(s) controller
 Δ structured perturbation
 δ1 first parameter perturbation term (perturbation term)
 δ2 second parameter perturbation term (perturbation term)