Controller Unit and Device for Resetting an Oscillator Excited by a Harmonic Oscillation, and Yaw Rate Sensor

• US 20140159822A1
• Filed: 12/15/2011
• Published: 06/12/2014
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Northrop Grumman Litef Gmbh (Northrop Grumman Corporation)
• Original Assignee: Gunter Spahlinger, Markus Ruf
• Inventors: Spahlinger, Gnter, Ruf, Markus
• Granted Patent: US 9,356,607 B2
• Time in Patent Office: Days
• US Class Current: 331/35
• CPC Class Codes: G05B 5/01 electric
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation

Abstract

A controller unit includes a PI-controller for harmonic command variables. The transfer function of the PI-controller has a conjugate complex pole at a controller angular frequency ω_r in the s-plane or a pole at e^±jωrT in the z-plane, wherein T is the sampling time of a discrete input signal of the PI-controller and ω_r is larger than 0. The controller angular frequency ω_r is chosen equal to the resonance angular frequency ω₀ of an oscillator. The controller parameters, are, for example determined by pole/zero compensation. The controller unit allows, for example, a broad band control of harmonic oscillators in rotation rate sensors.

Claims

1. A controller unit comprising a PI-controller with a proportional transfer element and an integrating transfer element, arranged parallel to the proportional transfer element, wherein a controller input of the controller unit is connected with both transfer elements, characterized in

that a transfer function of the PI-controller has a conjugate complex pole at a controller angular frequency ω

_r in the s-plane or a pole at e<sup>±

jω

rT</sup> in the z-plane, wherein T is the sampling time of a discrete input signal of the PI-controller and ω

_r is larger than 0.

2. The controller unit according to claim 1, wherein

an integral action coefficient of the integrating transfer element and an amplification factor of the proportional transfer element are chosen such that the PI-controller is suitable for generating, at admission with a harmonic input signal of the controller angular frequency ω

_r modulated by the step function at the controller input, a harmonic oscillation of the controller angular frequency ω

_r with rising amplitude at the controller output.

3. A device comprising

a moveably supported oscillator, which is excitable to an oscillation with the resonance angular frequency ω

₀ along a direction of excitation, and

the controller unit according to claim 2, wherein the controller angular frequency ω

_r is equal to the resonance angular frequency ω

₀.

4. The device according to claim 3, wherein

the integral action coefficient and the amplification factor are chosen such that the zeros of the transfer function of the PI-controller compensate poles of a transfer function of the oscillator.

5. The device according to claim 3, wherein

the PI-controller is a continuous PI-controller and

the ratio of integral action coefficient to amplification factor is equal to a damping s₀ of the oscillator in the direction of excitation.

6. The device according to claim 5, wherein

a controlled system comprising the oscillator has a system dead time T_S,

the controller unit comprises in series to the PI-controller a dead time element with a controller dead time T_R, and either

the PI-controller is an inverting controller and the product of the resonance angular frequency ω

₀ and the sum of the system dead time T_S and the controller dead time T_R is equal to π

/2 or

the PI-controller (225) is a non-inverting controller and the product of the resonance angular frequency ω

₀ and the sum of the system dead time T_S and the controller dead time T_R is equal to 3π

/2.

7. The device according to claim 3, wherein

the PI-controller is a discrete PI-controller, which is admittable with a discrete input signal emerging from a sampling with the sampling time T,

the oscillator has a damping s₀ in the direction of excitation, and

the ratio of the integral action coefficient to the amplification factor equals the ratio s₀:

(1−

s₀·

T).

8. The device according to claim 3, wherein

the PI-controller is a discrete PI-controller, which is admittable with a discrete input signal emerging from a sampling with the sampling time T,

the integral action coefficient and the amplification factor are chosen such that the transfer function of the closed loop of an equivalent baseband system has a double real eigenvalue.

9. The device according to claim 7, wherein

a controlled system comprising the oscillator has a system dead time β

_s·

T,

the controller unit comprises a dead time element with a controller dead time β

_D·

T in series to the discrete PI-controller, and either

the discrete PI-controller is an inverting controller and the product from the resonance angular frequency ω

₀ and the sum of the system dead time β

_s·

T, controller dead time β

_D·

T, and the half sampling time T/2 is equal to π

/2 or

the discrete PI-controller is a non-inverting controller and the product of the resonance angular frequency ω

₀ and the sum of the system dead time β

_s·

T, the controller dead time β

_D·

T, and the half sampling time T/2 is equal to 3π

/2.

10. The device according to claim 3, characterized by

a controller extension, arranged in series to the PI-controller, which acts as bandpass with a midband frequency at the resonance angular frequency ω

₀.

11. The device according to claim 10, wherein

a transfer function G_RE(z) of the controller extension with a bandwidth 1/T₁ is determined by the following equation:

12. The device according to claim 3, wherein

the device is a rotation rate sensor and the oscillator is an excitation unit, a Coriolis unit or a detection unit of the rotation rate sensor, wherein

the excitation unit is deflectable by a force transmitter along a direction of excitation and is suitable for an oscillation with the resonance angular frequency ω

₀,

the Coriolis unit is attached to the excitation unit such that the Coriolis unit follows a movement of the excitation unit along the direction of excitation and that the Coriolis unit is additionally moveable along a detection direction orthogonal to the direction of excitation, and

the detection unit is attached such to the excitation unit or to the coriolis unit that the detection unit either

follows a movement of the excitation unit along the direction of excitation and is additionally moveable along a detection direction orthogonal to the direction of excitation, or

follows a movement of the Coriolis unit along a detection direction orthogonal to the direction of excitation and is fixed along the direction of excitation.

13. A rotation rate sensor comprising

a moveably supported oscillator which is excitable in a direction of excitation to an oscillation with a resonance angular frequency ω

₀, and

a controller unit comprising a PI-controller with a proportional transfer element and an integrating transfer element arranged parallel to the proportional transfer element, wherein a controller input of the controller unit is connected with both transfer elements, characterized in that

the transfer function of the PI-controller has a conjugate complex pole at the resonance angular frequency ω

₀ in the s-plane or at e<sup>±

jω

0T</sup> in the z-plane, wherein T is the sampling time of a discrete input signal of the PI-controller and ω

₀ is larger than 0.

14. The rotation rate sensor according to claim 13, wherein

the oscillator is an excitation unit which is deflectable by a force transmitter along a direction of excitation and is suitable for an oscillation with the resonance angular frequency ω

₀.

15. A method for operating a rotation rate sensor, comprising

generating a measurement signal by a sensor reproducing a deflection of an oscillator, and

generating a controller signal for an actuator from the measurement signal, wherein the actuator counteracts the deviation of the oscillator from a harmonic oscillation with the resonance angular frequency ω

₀, the controller signal is deduced by means of a controller unit from the measurement signal, and the controller unit comprises a PI-controller with a proportional transfer element and an integrating transfer element arranged parallel to the proportional transfer element, wherein a controller input of the controller unit is connected with both transfer elements, wherein

a transfer function of the PI-controller has a conjugate complex pole at the resonance angular frequency ω

₀ in the s-plane or a pole at e<sup>±

jω

0T</sup> in the z-plane, wherein T is the sampling time of a discrete input signal of the PI-controller.

16. A method for manufacturing a rotation rate sensor, comprising

dimensioning a controller unit comprising a PI-controller with a proportional transfer element and an integrating transfer element, arranged parallel to the proportional transfer element, wherein a controller input of the controller unit is connected with both transfer elements characterized in

that the PI-controller is provided with a transfer function that has a conjugate complex pole at a controller angular frequency ω

_r in the s-plane or a pole at e<sup>±

jω

rT</sup> in the z-plane, wherein T is the sampling time of a discrete input signal of the PI-controller and ω

_r is larger than 0 and an integral action coefficient of the integrating transfer element and an amplification factor of the proportional transfer element are chosen such that the PI-controller is suitable for generating, at admission with a harmonic input signal of controller angular frequency ω

_r modulated by the step function at the controller input, a harmonic oscillation of the controller angular frequency ω

_r with rising amplitude at the controller output, and

the controller angular frequency ω

_r is chosen such that the controller angular frequency ω

_r is equal to the resonance angular frequency ω

₀ of an excitation unit of the rotation rate sensor.

17. The method according to claim 16, wherein

the integral action coefficient and the amplification factor are chosen such that the zeros of the transfer functions of the PI-controller compensate the poles of the transfer functions of the excitation unit.

18. The method according to claim 16, wherein

the PI-controller is a discrete PI-controller, which is admittable with a discrete input signal emerged from a sampling with sampling time T, and

the integral action coefficient and the amplification factor are chosen such that the transfer function of the closed loop of an equivalent baseband system has a double real eigenvalue.