Method and device for monitoring an actuator system

• US 9,792,256 B2
• Filed: 05/31/2013
• Issued: 10/17/2017
• Est. Priority Date: 06/04/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Wagner, Alexandre, Buehrle, Ralf
• Primary Examiner(s): Shah, Kamini S
• Assistant Examiner(s): Cook, Brian S
• Application Number:
  US13/906,954
• Publication Number:
  US 20130325421A1
• Time in Patent Office: 1,600 Days
• Field of Search: 703 2
• CPC Class Codes: G05B 23/0254 based on a quantitative model, e.g. mathematical relationships between inputs and outputs; functions: observer, Kalman filter, residual calculation, Neural Networks
• CPC Class Codes: G06F 17/13 Differential equations using digital differential analysers G06F7/64

Abstract

A method for monitoring an actuator in a physical system, including: providing a computer model that describes the actuator, the behavior of the actuator being represented by a computer model function and by one or more parameters of the computer model function; determining or adapting the values of the parameters of the computer model with the aid of one or more particular system quantities; determining an error when a specified error condition is fulfilled, the error condition defining when at least one of the parameters, and/or at least one quantity determined from a plurality of the parameters, lies outside a corresponding specified target deviation range for the relevant parameter or the relevant quantity.

Claims

1. A method for monitoring an actuator in a physical system, the method comprising:

monitoring, based on measured system quantities, the actuator, via a processor having a computer model that describes the actuator, the behavior of the actuator being represented by a computer model function and one or more parameters of the computer model function;

determining or adapting values of the parameters of the computer model with the aid of one or more particular system quantities;

determining an error when a specified error condition is fulfilled, the error condition defining when at least one of the parameters, and/or at least one quantity determined from a plurality of the parameters, lies outside a corresponding specified target deviation range for a relevant parameter or the relevant quantity; and

determining that a component of the actuator is faulty if the error is determined;

wherein the actuator includes an electromechanical throttle valve actuator for a throttle valve in an engine system having an internal combustion engine, the position of the throttle valve and/or an electric voltage applied to the electromechanical throttle valve actuator being specified as the system quantities, and

wherein for the actuator, the error condition on the basis of which a particular error can be identified include at least one of the following error types;

(i) an actuator spring is broken and/or missing, and/or a low resistance, and/or a short-circuit, and/or a weak motor, and/or defective permanent magnets;

(ii) an actuator friction is too high due to contamination and/or stiffness;

(iii) an actuator friction is too low due to wear, missing shaft sealant, and/or a broken coupling bar;

(iv) an actuator component has a high resistance; and

(v) the actuator component has a low resistance due to a short circuit, a weak motor, and/or defective permanent magnets, and

wherein error types (i) correspond to the following error condition;

α

>

S(α

)+Δ

α

&

η

/α

<

S(η

/α

)−

Δ

(η

/α

),

wherein error types (ii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iv) correspond to the following error conditions;

η

/α

>

S(η

/α

)+Δ

(η

/α

)

(α

<

S(α

)−

Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

), and

wherein error types (v) correspond to the following error conditions;

α

>

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

),

where R is a winding resistance of an actuator drive of the actuator, L is an inductance of a winding of the actuator drive, I represents an actuator current through the actuator drive, J represents a mass moment of inertia, and C_m and K_gear represent a gear ratio,

2. The method of claim 1, wherein, as a function of the relevant parameter, and/or as a function of that at least one quantity determined from a plurality of the parameters, whose values lie outside the target deviation range specified for the relevant parameter or for the relevant quantity determined from a plurality of the parameters, a particular component of the actuator allocated to the parameter or to the quantity is recognized as faulty.

3. The method of claim 1, wherein the computer model is determined through discretization of a differential equation system that describes the physical system having the actuator.

4. The method of claim 3, wherein the computer model is determined through discretization of the linear portion of a differential equation system that describes the actuator system, and through discretization of linear segments of the non-linear portion of the differential equation system that describes the actuator system.

5. The method of claim 1, wherein the computer model is solved through an iterative method, in real time, so as to obtain the parameters.

6. The method of claim 1, wherein the computer model for a linear portion of a differential equation that describes the throttle valve actuator uses parameters that can be determined regularly at specified intervals or during each computing cycle, and wherein the computer model includes a Tustin conversion.

7. A device for monitoring an actuator in a physical system, which includes a control device for operating the physical system having the actuator, comprising:

a monitoring arrangement to monitor, based on measured system quantities, the actuator, via a processor having a computer model that describes the actuator, the behavior of the actuator being represented by a computer model function and one or more parameters of the computer model function;

wherein the monitoring arrangement is configured to determine or adapt values of the parameters of the computer model with the aid of one or more particular system quantities,

wherein the monitoring arrangement is configured to determine an error when a specified error condition is fulfilled, the error condition defining when at least one of the parameters, and/or at least one quantity determined from a plurality of the parameters, lies outside a corresponding specified target deviation range for a relevant parameter or the relevant quantity,

wherein the monitoring arrangement is configured to determine that a component of the actuator is faulty if the error is determined,

wherein the actuator includes an electromechanical throttle valve actuator for a throttle valve in an engine system having an internal combustion engine, the position of the throttle valve and/or an electric voltage applied to the electromechanical throttle valve actuator being specified as the system quantities, and

wherein for the actuator, the error condition on the basis of which a particular error can be identified include at least one of the following error types;

(i) an actuator spring is broken and/or missing, and/or a low resistance, and/or a short-circuit, and/or a weak motor, and/or defective permanent magnets;

(ii) an actuator friction is too high due to contamination and/or stiffness;

(iii) an actuator friction is too low due to wear, missing shaft sealant, and/or a broken coupling bar;

(iv) an actuator component has a high resistance; and

(v) the actuator component has a low resistance due to a short circuit, a weak motor, and/or defective permanent magnets, and

wherein error types (i) correspond to the following error condition;

α

>

S(α

)+Δ

α

&

η

/α

<

S(η

/α

)−

Δ

(η

/α

),

wherein error types (ii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iv) correspond to the following error conditions;

η

/α

>

S(η

/α

)+Δ

(η

/α

)

(α

<

S(α

)−

Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

), and

wherein error types (v) correspond to the following error conditions;

α

>

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

),

where R is a winding resistance of an actuator drive of the actuator, L is an inductance of a winding of the actuator drive, I represents an actuator current through the actuator drive, J represents a mass moment of inertia, and C_m and K_gear represent a gear ratio,

8. The device of claim 7, wherein the computer model for a linear portion of a differential equation that describes the throttle valve actuator uses parameters that can be determined regularly at specified intervals or during each computing cycle, and wherein the computer model includes a Tustin conversion.

9. An actuator system, comprising:

an actuator; and

a device for monitoring an actuator in a physical system, which includes a control device for operating the physical system having the actuator, including;

a monitoring arrangement to monitor, based on measured system quantities, the actuator, via a processor having a computer model that describes the actuator, the behavior of the actuator being represented by a computer model function and one or more parameters of the computer model function;

wherein the monitoring arrangement is configured to determine or adapt values of the parameters of the computer model with the aid of one or more particular system quantities,

wherein the monitoring arrangement is configured to determine an error when a specified error condition is fulfilled, the error condition defining when at least one of the parameters, and/or at least one quantity determined from a plurality of the parameters, lies outside a corresponding specified target deviation range for a relevant parameter or the relevant quantity,

wherein the monitoring arrangement is configured to determine that a component of the actuator is faulty if the error is determined, and

wherein the actuator includes an electromechanical throttle valve actuator for a throttle valve in an engine system having an internal combustion engine, the position of the throttle valve and/or an electric voltage applied to the electromechanical throttle valve actuator being specified as the system quantities, and

wherein for the actuator, the error condition on the basis of which a particular error can be identified include at least one of the following error types;

(i) an actuator spring is broken and/or missing, and/or a low resistance, and/or a short-circuit, and/or a weak motor, and/or defective permanent magnets;

(ii) an actuator friction is too high due to contamination and/or stiffness;

(iii) an actuator friction is too low due to wear, missing shaft sealant, and/or a broken coupling bar;

(iv) an actuator component has a high resistance; and

(v) the actuator component has a low resistance due to a short circuit, a weak motor, and/or defective permanent magnets, and

wherein error types (i) correspond to the following error condition;

α

>

S(α

)+Δ

α

&

η

/α

<

S(η

/α

)−

Δ

(η

/α

),

wherein error types (ii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iv) correspond to the following error conditions;

η

/α

>

S(η

/α

)+Δ

(η

/α

)

(α

<

S(α

)−

Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

), and

wherein error types (v) correspond to the following error conditions;

α

>

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

),

where R is a winding resistance of an actuator drive of the actuator, L is an inductance of a winding of the actuator drive, I represents an actuator current through the actuator drive, J represents a mass moment of inertia, and C_m and K_gear represent a gear ratio,

10. The actuator system of claim 9, wherein the computer model for a linear portion of a differential equation that describes the throttle valve actuator uses parameters that can be determined regularly at specified intervals or during each computing cycle, and wherein the computer model includes a Tustin conversion.

11. A non-transitory computer readable medium having a computer program, which is executable by a processor, comprising:

a program code arrangement having program code for monitoring an actuator in a physical system, by performing the following;

monitoring, based on measured system quantities, the actuator, via a processor having a computer model that describes the actuator, the behavior of the actuator being represented by a computer model function and one or more parameters of the computer model function;

determining or adapting values of the parameters of the computer model with the aid of one or more particular system quantities;

determining an error when a specified error condition is fulfilled, the error condition defining when at least one of the parameters, and/or at least one quantity determined from a plurality of the parameters, lies outside a corresponding specified target deviation range for a relevant parameter or the relevant quantity; and

determining that a component of the actuator is faulty if the error is determined;

wherein the actuator includes an electromechanical throttle valve actuator for a throttle valve in an engine system having an internal combustion engine, the position of the throttle valve and/or an electric voltage applied to the electromechanical throttle valve actuator being specified as the system quantities, and

wherein for the actuator, the error condition on the basis of which a particular error can be identified include at least one of the following error types;

(i) an actuator spring is broken and/or missing, and/or a low resistance, and/or a short-circuit, and/or a weak motor, and/or defective permanent magnets;

(ii) an actuator friction is too high due to contamination and/or stiffness;

(iii) an actuator friction is too low due to wear, missing shaft sealant, and/or a broken coupling bar;

(iv) an actuator component has a high resistance; and

(v) the actuator component has a low resistance due to a short circuit, a weak motor, and/or defective permanent magnets, and

wherein error types (i) correspond to the following error condition;

α

>

S(α

)+Δ

α

&

η

/α

<

S(η

/α

)−

Δ

(η

/α

),

wherein error types (ii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iii) correspond to the following error conditions;

S(α

)−

Δ

α

<

α

<

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

)&

S(η

/α

)−

Δ

(η

/α

)<

η

/α

<

S(η

/α

)+Δ

(η

/α

),

wherein error types (iv) correspond to the following error conditions;

η

/α

>

S(η

/α

)+Δ

(η

/α

)

(α

<

S(α

)−

Δ

α

&

μ

/α

>

S(μ

/α

)+Δ

(μ

/α

), and

wherein error types (v) correspond to the following error conditions;

α

>

S(α

)+Δ

α

&

μ

/α

<

S(μ

/α

)−

Δ

(μ

/α

),

where R is a winding resistance of an actuator drive of the actuator, L is an inductance of a winding of the actuator drive, I represents an actuator current through the actuator drive, J represents a mass moment of inertia, and C_m and K_gear represent a gear ratio, and where

12. The computer readable medium of claim 11, wherein, as a function of that at least one parameter, and/or as a function of that at least one quantity determined from a plurality of the parameters, whose values lie outside the target deviation range specified for the relevant parameter or for the relevant quantity determined from a plurality of the parameters, a particular component of the actuator allocated to the parameter or to the quantity is recognized as faulty.

13. The computer readable medium of claim 11, wherein the computer model is determined through discretization of a differential equation system that describes the actuator system.

14. The computer readable medium of claim 13, wherein the computer model is determined through discretization of the linear portion of the differential equation system that describes the actuator system, and through discretization of linear segments of the non-linear portion of the differential equation system that describes the actuator system.

15. The computer readable medium of claim 11, wherein the computer model is solved through an iterative method, in real time, so as to obtain the parameters.

16. The computer readable medium of claim 11, wherein the computer model for a linear portion of a differential equation that describes the throttle valve actuator uses parameters that can be determined regularly at specified intervals or during each computing cycle, and wherein the computer model includes a Tustin conversion.