Resonant ring micro-electro-mechanical gyroscope time-sharing digital control system

Abstract

The invention belongs to the field of closed-loop control of resonant ring micro-electro-mechanical gyroscopes, and particularly relates to a time-sharing digital control system of a resonant ring micro-electro-mechanical gyroscope. Comprising a resonant ring micro-electro-mechanical gyroscope, two modal driving / detection electrode time-sharing switching modules, two modal detection modules, two analog-to-digital converters, three digital-to-analog converters, three single-ended to differential driving modules and a digital processing unit, and the digital processing unit generates driving / detection time-sharing control signals S1 and S2. Performing digital demodulation, filtering, control resolving, direct digital frequency generation and modulation processing on the first modal detection signal to realize time-sharing stable tracking closed-loop control of the resonant frequency of the gyroscope and time-sharing stable closed-loop control of the vibration amplitude; digital demodulation, filtering, control resolving and modulation processing are carried out on the second modal detection signal, and stable control over gyroscope orthogonal compensation and time-sharing stable closed-loop control over the gyroscope angular rate are achieved.

Description

Technical Field

[0001] The invention belongs to a resonant ring micro-electro-mechanical gyroscope closed-loop control technology, and in particular relates to a resonant ring micro-electro-mechanical gyroscope time-sharing digital control system. Background Art

[0002] The resonant ring MEMS gyroscope is a type of MEMS gyroscope with a natural axisymmetric structural property. It is based on semiconductor process technology and is particularly suitable for mass production. It has the advantages of low cost, small size, light weight, low power consumption, and resistance to shock and vibration. It can be widely used in attitude stabilization, industrial control, consumer electronics and other fields. With the improvement of accuracy, it also has broad application prospects in the field of navigation.

[0003] Practical resonant ring MEMS gyroscopes usually use closed-loop control detection technology, which requires the gyroscope to work on the basis of a stable closed loop of resonant frequency tracking loop, vibration amplitude loop, orthogonal compensation loop and angular velocity loop to achieve high-precision and high-bandwidth measurement of angular velocity.

[0004] The resonant ring MEMS gyroscope has many electrodes with complex distribution. The existing closed-loop control scheme generally adopts the method of implementing feedback drive and detection simultaneously, and has a relatively complex analog detection processing circuit. It has the disadvantages of large detection signal crosstalk, complex analog circuit design and implementation, and the gyroscope performance is easily affected by the ambient temperature. Summary of the invention

[0005] Purpose of the invention: to provide a time-sharing digital control system for a resonant ring micro-electromechanical gyroscope. On the one hand, the time-sharing feedback drive and time-sharing detection of a resonant ring micro-electromechanical gyroscope resonant frequency stabilization tracking loop, a vibration amplitude stabilization loop, and an angular velocity stabilization loop are realized through time-sharing control, as well as the time-sharing detection and DC continuous feedback drive control of an orthogonal compensation stabilization loop, thereby reducing the crosstalk of the AC feedback drive voltage on the detection and improving the signal detection accuracy. On the other hand, as many functional modules as possible are realized in the digital domain, reducing the difficulty of designing and realizing analog circuits, while reducing the gyroscope resonant frequency drift caused by factors such as the external ambient temperature, thereby improving the gyroscope measurement accuracy.

[0006] Technical solution:

[0007] A resonant ring micro-electromechanical gyroscope time-sharing digital control system comprises: a first modal drive / detection electrode time-sharing switching module, a first modal detection module, a first analog-to-digital converter, a first digital-to-analog converter, a first single-ended to differential drive module, a digital processing unit, a second modal drive / detection electrode time-sharing switching module, a second modal detection module, a second analog-to-digital converter, a second digital-to-analog converter, a second single-ended to differential drive module, a third digital-to-analog converter, and a third single-ended to differential drive module, wherein the digital processing unit comprises: a first synchronous detection processing module, a first interpolation filter, a first phase-sensitive demodulator, a first low-pass filter, a second low-pass filter, a first controller, a second controller, a direct digital frequency generation module, a first modulation module, a time-sharing control timing generation module, a second synchronous detection processing module, a second interpolation filter, a second phase-sensitive demodulator, a third low-pass filter, a fourth low-pass filter, a third controller, a fourth controller, and a second modulation module.

[0008] The positive electrode and negative electrode of the first modal drive / detection electrode of the resonant ring micro-electromechanical gyroscope are respectively connected to the two input and output ends of the first modal drive / detection electrode time-sharing switching module, the first modal detection module, the first analog-to-digital converter, the first synchronous detection processing module, the first interpolation filter, and the first phase-sensitive demodulator are connected in sequence, the first output end of the first phase-sensitive demodulator is connected in sequence with the first low-pass filter and the first modulation module of the first controller, the second output end of the first phase-sensitive demodulator is connected in sequence with the second low-pass filter, the second controller, and the direct digital frequency generation module, and then the direct digital frequency generation module generates two signals of cos and sin, wherein one sin signal is connected to the second modulation module, and the other cos signal is connected to the first modulation module, the output end of the first modulation module is connected to the first digital-to-analog converter, the first single-ended to differential drive module, and the input end of the first modal drive / detection electrode time-sharing switching module, and returns to the first modal drive / detection electrode on the resonant ring micro-electromechanical gyroscope through the first modal drive / detection electrode time-sharing switching module;

[0009] At the same time, the positive electrode and the negative electrode of the second modal drive / detection electrode on the resonant ring micro-electromechanical gyroscope are respectively connected to the two input and output ends of the second modal drive / detection electrode time-sharing switching module, the second modal drive / detection electrode time-sharing switching module is connected in sequence with the second modal detection module, the second analog-to-digital converter, the second synchronous detection processing module, the second interpolation filter, and the second phase-sensitive demodulator, the first output end of the second phase-sensitive demodulator is connected in sequence with the third low-pass filter, the third controller, the second modulation module, the second digital-to-analog converter, the second single-ended to differential drive module, and the second modal drive / detection electrode time-sharing switching module, and returns to the second modal drive / detection electrode on the resonant ring micro-electromechanical gyroscope through the second modal drive / detection electrode time-sharing switching module, the second output end of the second phase-sensitive demodulator is connected in sequence with the fourth low-pass filter, the fourth controller, the third digital-to-analog converter, and the third single-ended to differential drive module, and the two output ends of the third single-ended to differential drive module are connected to the two orthogonal electrodes of the resonant ring micro-electromechanical gyroscope;

[0010] One output end of the time-sharing control timing generation module is connected to the control end of the first mode driving / detecting electrode time-sharing switching module, the control end of the second mode driving / detecting electrode time-sharing switching module, the control end of the first mode detection module, and the control end of the second mode detection module; the other output end of the time-sharing control timing generation module is connected to the control end of the first synchronous detection processing module and the control end of the second synchronous detection processing module.

[0011] The time-sharing control timing generation module in the digital processing unit is used to generate the first mode and the second mode driving and detecting time-sharing working control signals S1 and S2, both of which have the same frequency, so that the gyroscope is in an alternating working mode of driving period and detecting period.

[0012] Further, the control signal S1 generated by the time-sharing control timing generation module in the digital processing unit has two states, high and low. When S1 is in the high state, the first mode drive / detection electrode time-sharing switching module connects the first single-ended to differential drive module to the first mode drive / detection electrodes X+ and X-, disconnects the first mode detection module from the first mode drive / detection electrodes X+ and X-, and resets the first mode detection module. At the same time, the second mode drive / detection electrode time-sharing switching module connects the second single-ended to differential drive module to the second mode drive / detection electrodes X+ and X-, disconnects the second mode detection module from the second mode drive / detection electrodes X+ and X-, and resets the second mode detection module. The gyroscope is in the drive working period. When S1 is in the low state, the first mode drive / detection electrode time-sharing switching module disconnects the first single-ended to differential drive module from the first mode drive / detection electrodes X+ and X-, connects the first mode detection module to the first mode drive / detection electrodes X+ and X. At the same time, the second mode drive / detection electrode time-sharing switching module disconnects the second single-ended to differential drive module from the second mode drive / detection electrodes X+ and X-, connects the second mode detection module to the second mode drive / detection electrodes X+ and X. The gyroscope is in the detection working period.

[0013] Further, the control signal S2 generated by the time-sharing control timing generation module in the digital processing unit has two states, high and low. Only when S2 is in the high state, the first synchronous detection processing module and the second synchronous detection processing module respectively perform integral accumulation processing on the output signals of the first analog-to-digital converter and the second analog-to-digital converter to obtain the instantaneous position detection information of the first mode and the second mode of the gyroscope respectively.

[0014] Further, the control signals S1 and S2 generated by the time-sharing control timing generation module in the digital processing unit are in the form of square waves with the same frequency, and the frequency is f s , f s is at least 10 times greater than f d , where f d is the resonance frequency of the gyroscope drive mode.

[0015] Further, the periods of the two control signals S1 and S2 are T, the high state time of S1 is T1, the low state time is T2, the high state time of S2 is T3, and they satisfy the relationships: 0 < T1 < T, 0 < T2 < T, T1 + T2 = T, 0 < T3 < T2, and the rising edge of S1 coincides with the falling edge of S2.

[0016] Further, the first interpolation filter and the second interpolation filter in the digital processing unit up-sample the digital processing sampling frequencies of the first mode and the second mode detection signals from f s to f clk, effectively reducing the phase noise of the subsequent phase-sensitive demodulation processing, and also has the function of low-pass filtering, where f clk is the operating frequency of the digital processing unit.

[0017] Furthermore, the first analog-to-digital converter, the first digital-to-analog converter, the second analog-to-digital converter, and the second digital-to-analog converter all use high-speed converters, and the conversion sampling rate is the same as the operating frequency of the digital processing unit, which is f clk .

[0018] Furthermore, the direct digital frequency generation module in the digital processing unit simultaneously generates cosine cos and sine sin AC digital signals according to the signals processed by the first phase-sensitive demodulator, the second low-pass filter, and the second controller, wherein the cos signal is used as the carrier signal of the first modulation module and the second modulation module, and the sin and cos signals are used as in-phase and quadrature demodulation reference signals of the first phase-sensitive demodulator and the second phase-sensitive demodulator, respectively.

[0019] Furthermore, the first modulation module and the second modulation module in the digital processing unit normally output modulation signals only when the gyroscope is in the driving working period, and output a normally zero signal in the detection working period.

[0020] Furthermore, the first mode drive and the second mode drive of the gyroscope both adopt a differential drive mode, the first mode detection and the second mode detection both adopt a differential detection mode, and the differential drive common mode voltage and the differential detection common mode voltage both have a DC voltage difference V with the voltage applied to the gyroscope mass block. DC ,|V DC |>0.

[0021] Beneficial effects:

[0022] (1) The resonant ring micro-electromechanical gyroscope time-sharing digital control system proposed in the present invention enables the driving and detection work of the first mode and the second mode of the gyroscope to be carried out alternately in a time-sharing manner, with complementary overlap in time, thereby avoiding the crosstalk of the strong AC driving signal on the weak detection signal. At the same time, the digital processing of the detection signal adopts integration accumulation and interpolation filtering processing, which effectively improves the signal-to-noise ratio of the detection processing signal;

[0023] (2) The resonant ring micro-electromechanical gyroscope time-sharing digital control system proposed by the present invention has a time-sharing control sequence generated by a time-sharing control sequence generation module in a digital processing unit, and the time-sharing working frequency and the time proportion of the driving working period and the detection working period can be flexibly adjusted, which can flexibly adapt to different gyroscope head characteristics. In addition, most of the functions are completed by the digital processing unit, which greatly reduces the difficulty of designing and implementing analog circuits, and at the same time reduces the gyroscope resonance frequency drift caused by factors such as external environmental temperature, thereby improving the gyroscope measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention, and is a functional block diagram of a time-sharing digital control system for a resonant ring micro-electromechanical gyroscope;

[0025] Figure 2 It is a schematic diagram of the time-sharing control timing of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

[0027] Combination Figure 1 The present invention proposes a resonant ring micro-electromechanical gyroscope time-sharing digital control system, comprising a resonant ring micro-electromechanical gyroscope 01, a first modal drive / detection electrode time-sharing switching module 02, a first modal detection module 03, a first analog-to-digital converter 04, a first digital-to-analog converter 06, a first single-ended to differential drive module 07, a digital processing unit 05, a second modal drive / detection electrode time-sharing switching module 08, a second modal detection module 09, a second analog-to-digital converter 10, a second digital-to-analog converter 11, a second single-ended to differential drive module 12, a third digital-to-analog converter 32, and a third single-ended to differential drive module 13.

[0028] Among them, the digital processing unit 05 further includes a first synchronous detection processing module 14, a first interpolation filter 15, a first phase-sensitive demodulator 16, a first low-pass filter 17, a second low-pass filter 20, a first controller 18, a second controller 21, a direct digital frequency generation module 22, a first modulation module 19, a time-sharing control timing generation module 23, a second synchronous detection processing module 24, a second interpolation filter 25, a second phase-sensitive demodulator 26, a third low-pass filter 27, a fourth low-pass filter 30, a third controller 28, a fourth controller 31, and a second modulation module 29.

[0029] The connection relationship between the various parts of the system is that the positive and negative electrodes of the first mode drive / detection electrode of the resonant ring micro-electromechanical gyroscope 01 are respectively connected to the two input and output ends of the first mode drive / detection electrode time-sharing switching module 02, the first mode drive / detection electrode time-sharing switching module 02, the first mode detection module 03, the first analog-to-digital converter 04, the first synchronous detection processing module 14, the first interpolation filter 15, and the first phase-sensitive demodulator 16 are connected in sequence, the first output end of the first phase-sensitive demodulator 16 is connected to the first low-pass filter 17, the first controller 18 and the first modulation module 19 in sequence, and the second output end of the first phase-sensitive demodulator 16 is connected to the first low-pass filter 17, the first controller 18 and the first modulation module 19 in sequence. After the second low-pass filter 20, the second controller 21, and the direct digital frequency generation module 22 are connected in sequence, the direct digital frequency generation module 22 generates two signals, cos and sin, wherein one sin signal is connected to the second modulation module 29, and the other cos signal is connected to the first modulation module 19, and the output end of the first modulation module 19 is connected to the input end of the first digital-to-analog converter 06, the first single-ended to differential driving module 07, and the first modal driving / detecting electrode time-sharing switching module 02, and returns to the first modal driving / detecting electrode on the resonant ring micro-electromechanical gyroscope 01 through the first modal driving / detecting electrode time-sharing switching module 02;

[0030] At the same time, the positive and negative electrodes of the second mode drive / detection electrode on the resonant ring micro-electromechanical gyroscope 01 are respectively connected to the two input and output ends of the second mode drive / detection electrode time-sharing switching module 08, the second mode drive / detection electrode time-sharing switching module 08 is connected to the second mode detection module 09, the second analog-to-digital converter 10, the second synchronous detection processing module 24, the second interpolation filter 25, and the second phase-sensitive demodulator 26 in sequence, and the first output end of the second phase-sensitive demodulator 26 is connected to the third low-pass filter 27, the third controller 28, the second modulation module 29, and the second digital-to-analog converter The second output end of the second phase-sensitive demodulator 26 is connected to the fourth low-pass filter 30, the fourth controller 31, the third digital-to-analog converter 32, and the third single-ended to differential driving module 13 in sequence, and the two output ends of the third single-ended to differential driving module 13 are connected to the two orthogonal electrodes of the resonant ring micro-electro-mechanical gyroscope 01;

[0031] One output end of the time-sharing control timing generation module 23 is connected to the control end of the first modal drive / detection electrode time-sharing switching module 02, the control end of the second modal drive / detection electrode time-sharing switching module 08, the control end of the first modal detection module 03, and the control end of the second modal detection module 09; the other output end of the time-sharing control timing generation module 23 is connected to the control end of the first synchronous detection processing module 14 and the control end of the second synchronous detection processing module 24.

[0032] The control signals S1 and S2 generated by the time-sharing control sequence generation module 23 in the digital processing unit 05 are as follows: Figure 2 As shown. Both S1 and S2 have two states, high and low. When S1 is in the high state, the first modal drive / detection electrode time-sharing switching module 02 connects the first single-ended to differential drive module 07 with the first modal drive / detection electrodes X+ and X-, disconnects the first modal detection module 03 from the first modal drive / detection electrodes X+ and X-, and resets the first modal detection module 03. At the same time, the second modal drive / detection electrode time-sharing switching module 08 connects the second single-ended to differential drive module 12 with the second modal drive / detection electrodes X+ and X-, disconnects the second modal detection module 09 from the second modal drive / detection electrodes X+ and X-, and resets the first modal detection module 03. Reset, the gyroscope is in the driving working period; when S1 is in a low state, the first mode drive / detection electrode time-sharing switching module 02 disconnects the first single-ended to differential drive module 07 from the first mode drive / detection electrodes X+ and X-, and connects the first mode detection module 03 to the first mode drive / detection electrodes X+ and X-, while the second mode drive / detection electrode time-sharing switching module 08 disconnects the second single-ended to differential drive module 12 from the second mode drive / detection electrodes X+ and X-, and connects the second mode detection module 09 to the second mode drive / detection electrodes X+ and X-, and the gyroscope is in the detection working period. In addition, only when S2 is in a high state, the first synchronous detection processing module 14 and the second synchronous detection processing module 24 respectively perform integral accumulation processing on the output signals of the first analog-to-digital converter 04 and the second analog-to-digital converter 11, and obtain the instantaneous position detection information of the first mode and the second mode of the gyroscope respectively.

[0033] During the detection period, the first-mode detection module 03 picks up the signals of the first-mode detection electrodes X+ and X-. After passing through the first analog-to-digital converter 04, the first synchronous detection processing module 14, the first interpolation filter 15, and the first phase-sensitive demodulator 16 in the digital processing unit 05, on the one hand, through in-phase demodulation, filtering by the first low-pass filter 17, the first controller 18, and the operation and processing of the first modulation module 19, and then through the first digital-to-analog converter 06 and the first single-ended-to-differential drive module 07, it is fed back to the first-mode drive electrodes X+ and X- during the drive period to achieve stable closed-loop control of the gyro vibration amplitude. On the other hand, through quadrature demodulation, filtering by the second low-pass filter 20, the second controller 21, the direct digital frequency generation module 22, and the operation and processing of the first modulation module 19, it also passes through the first digital-to-analog converter 06 and the first single-ended-to-differential drive module 07 and is fed back to the first-mode drive electrodes X+ and X- during the drive period to achieve stable closed-loop control of the gyro resonance frequency tracking;

[0034] Meanwhile, during the detection period, the second-mode detection module 09 picks up the signals of the second-mode detection electrodes Y+ and Y-. After passing through the second analog-to-digital converter 10, the second synchronous detection processing module 24, the second interpolation filter 25, and the second phase-sensitive demodulator 26 in the digital processing unit 05, on the one hand, through in-phase demodulation, filtering by the third low-pass filter 27, the third controller 28, and the operation and processing of the second modulation module 29, and then through the second digital-to-analog converter 11 and the second single-ended-to-differential drive module 12, it is fed back to the second-mode drive electrodes Y+ and Y- during the drive period to achieve stable closed-loop control of the gyro angular rate. On the other hand, through quadrature demodulation, filtering by the fourth low-pass filter 30, and the operation and processing of the fourth controller 31, it passes through the third digital-to-analog converter 32 and the third single-ended-to-differential drive module 13 and is fed back to the quadrature electrodes Q+ and Q- to achieve stable closed-loop control of the gyro quadrature compensation.

[0035] Combined Figure 2 , the time-sharing control timing generation module 23 in the digital processing unit 05 generates control signals S1 and S2 in the form of square waves with the same frequency, and its frequency is f s , the period is T, and f s is at least 10 times greater than f d , where f d is the resonance frequency of the gyro drive mode. The high-state time of S1 is T1, the low-state time is T2, the high-state time of S2 is T3, and they satisfy the relationships: 0 < T1 < T, 0 < T2 < T, T1 + T2 = T, 0 < T3 < T2, and the rising edge of S1 coincides with the falling edge of S2.

[0036] The first interpolation filter 15 and the second interpolation filter 25 in the digital processing unit 05 upsample the digital processing sampling frequency of the first-mode and second-mode detection signals from f s to f clk, which can effectively reduce the phase noise of the subsequent phase-sensitive demodulation processing and also has the function of low-pass filtering, where f clk is the operating frequency of the digital processing unit;

[0037] The direct digital frequency generation module 22 in the digital processing unit 05 simultaneously generates cosine cos and sine sin AC digital signals according to the signals after orthogonal demodulation by the first phase-sensitive demodulator 16, filtering by the second low-pass filter 20, and operation processing by the second controller 21, wherein the cos signal is used as the carrier signal of the first modulation module 19 and the second modulation module 29, and the sin and cos signals are used as in-phase and orthogonal demodulation reference signals of the first phase-sensitive demodulator 16 and the second phase-sensitive demodulator 26, respectively;

[0038] The first modulation module 19 and the second modulation module 29 in the digital processing unit 05 normally output modulation signals only when the gyro is in the driving working period, and output a normally zero signal in the detection working period;

[0039] The first controller 18, the second controller 21, the third controller 28 and the fourth controller 31 in the digital processing unit 05 usually adopt a proportional integral control method; the first modulation module 19 and the second modulation module 29 usually adopt a multiplier modulation method; the first phase-sensitive demodulator 16 and the second phase-sensitive demodulator 26 usually adopt a multiplier demodulation method;

[0040] The first mode drive and the second mode drive of the gyroscope both adopt differential drive mode, the first mode detection and the second mode detection both adopt differential detection mode, and the differential drive common mode voltage and the differential detection common mode voltage both have a DC voltage difference V with the voltage applied to the gyroscope mass block. DC , and |V DC |>0.

[0041] In summary, the present invention discloses a resonant ring micro-electromechanical gyroscope time-sharing digital control system, and the time-sharing control timing generation module 23 in the digital processing unit 05 controls the first mode drive / detection electrode time-sharing switching module 02, the second mode drive / detection electrode time-sharing switching module 08, the first mode detection module 03, the second mode detection module 09, the first synchronous detection processing module 14, the second synchronous detection processing module 24, etc. through control signals S1 and S2 to make the gyroscope in an alternating working mode of the drive period and the detection period, and realize the stable tracking of the gyroscope drive amplitude, the drive resonant frequency, the orthogonal compensation and the stable closed-loop control of the angular rate. Most of the functions of the present invention are completed by the digital processing unit 05, which can greatly reduce the difficulty of realizing the system analog circuit, and the digital control time-sharing work can effectively reduce crosstalk, improve the signal-to-noise ratio of the detection circuit, improve the gyroscope accuracy and reduce the influence of the ambient temperature on the gyroscope accuracy.

[0042] Based on the above implementation content, combined with Figure 1 and Figure 2 , examples are given to further illustrate.

[0043] Embodiment 1

[0044] As an embodiment of the present invention, the gyro resonance frequency f d =12KHz, the working clock frequency f of the digital processing unit 05 clk =20MHz, the time-sharing control sequence generation module 23 generates control signals S1, S2, the frequency f s =500KHz, T1:T2=3:1, that is, the high state for feedback drive accounts for 75%, and the low state for detection accounts for 25%. In the T3 period, the transition process of the first modal detection module 03 ends and is in a relatively stable working state. Its output signal is sampled at high speed by the first analog-to-digital converter 04, and the adoption rate is f clk The first synchronous detection processing module 14 performs integration and accumulation processing, and the sampling rate becomes f s , the first interpolation filter 15 is processed, and the sampling rate becomes f clk Then, on the one hand, after the first phase-sensitive demodulator 16 performs in-phase sin phase demodulation, the first low-pass filter 17 performs filtering, the first controller 18 and the first modulation module 19 perform calculation processing, and then the first digital-to-analog converter 06 and the first single-ended to differential drive module 07 are fed back to the first modal drive / detection electrodes X+ and X- in the T1 driving period of the next time-sharing cycle, so as to realize the stable closed-loop control of the gyro vibration amplitude; on the other hand, after the first phase-sensitive demodulator 16 performs orthogonal cos phase demodulation, the second low-pass filter 20 performs filtering, the second controller 21 and the direct digital frequency generation module 22 generate the cos digital AC signal, and the first modulation module 19 performs modulation calculation processing, and then the first digital-to-analog converter 06 and the first single-ended to differential drive module 07 are fed back to the first modal drive / detection electrodes X+ and X- in the T1 driving period of the next time-sharing cycle, so as to realize the stable tracking closed-loop control of the gyro resonance frequency. Similarly, in the T3 period, the transition process of the second modal detection module 09 ends and it is in a relatively stable working state. Its output signal is sampled at high speed by the second analog-to-digital converter 10, and the rate is f clk The second synchronous detection processing module 24 performs integration and accumulation processing, and the sampling rate becomes f s , the second interpolation filter 25 is processed, using 40 times upsampling, and the sampling rate becomes f clkThen, on the one hand, after in-phase sin phase demodulation by the second phase-sensitive demodulator 26, filtering by the third low-pass filter 27, calculation processing by the third controller 28, and the second modulation module 29, the second digital-to-analog converter 11 and the second single-ended to differential driving module 12 are fed back to the second modal driving / detecting electrodes Y+ and Y- in the T1 driving period of the next time-sharing cycle, so as to realize the stable closed-loop control of the gyro angular rate; on the other hand, after orthogonal cos phase demodulation by the second phase-sensitive demodulator 26, filtering by the fourth low-pass filter 30, and calculation processing by the fourth controller 31, the third digital-to-analog converter 32 and the third single-ended to differential driving module 13 are fed back to the gyro orthogonal electrodes Q+ and Q-, so as to realize the stable closed-loop control of the gyro orthogonal compensation. Since the driving period of the embodiment accounts for 75% of the entire time-sharing period T, the driving capacity is 0.75 times that of the non-time-sharing under the same conditions, the driving capacity is relatively strong, and it is suitable for the control of the resonant ring micro-electromechanical gyroscope with a small Q value.

[0045] Embodiment 2

[0046] As another embodiment of the present invention, as an embodiment of the present invention, the gyro resonance frequency f d =15KHz, the working clock frequency f of the digital processing unit 05 clk =20MHz, the time-sharing control sequence generation module 23 generates control signals S1, S2, the frequency f s =500KHz, T1:T2=1:3, that is, the high state for feedback drive accounts for 25%, and the low state for detection accounts for 75%. In the T3 period, the transition process of the first modal detection module 03 ends and it is in a relatively stable working state. Its output signal is sampled at a high speed by the first analog-to-digital converter 04, and the adoption rate is f clk The first synchronous detection processing module 14 performs integration and accumulation processing, and the sampling rate becomes f s , the first interpolation filter 15 is processed, and the sampling rate becomes f clkThen, on the one hand, after the first phase-sensitive demodulator 16 performs in-phase sin phase demodulation, the first low-pass filter 17 performs filtering, the first controller 18 and the first modulation module 19 perform calculation processing, and then the first digital-to-analog converter 06 and the first single-ended to differential drive module 07 are fed back to the first modal drive / detection electrodes X+ and X- in the T1 driving period of the next time-sharing cycle, so as to realize the stable closed-loop control of the gyro vibration amplitude; on the other hand, after the first phase-sensitive demodulator 16 performs orthogonal cos phase demodulation, the second low-pass filter 20 performs filtering, the second controller 21 and the direct digital frequency generation module 22 generate the cos digital AC signal, and the first modulation module 19 performs modulation calculation processing, and then the first digital-to-analog converter 06 and the first single-ended to differential drive module 07 are fed back to the first modal drive / detection electrodes X+ and X- in the T1 driving period of the next time-sharing cycle, so as to realize the stable tracking closed-loop control of the gyro resonance frequency. Similarly, in the T3 period, the transition process of the second modal detection module 09 ends and it is in a relatively stable working state. Its output signal is sampled at high speed by the second analog-to-digital converter 10, and the rate is f clk The second synchronous detection processing module 24 performs integration and accumulation processing, and the sampling rate becomes f s , the second interpolation filter 25 is processed, using 40 times upsampling, and the sampling rate becomes f clk Then, on the one hand, after in-phase sin phase demodulation by the second phase-sensitive demodulator 26, filtering by the third low-pass filter 27, calculation processing by the third controller 28, and the second modulation module 29, the second digital-to-analog converter 11 and the second single-ended to differential driving module 12 are fed back to the second modal driving / detecting electrodes Y+ and Y- in the T1 driving period of the next time-sharing cycle, so as to realize the stable closed-loop control of the gyro angular rate; on the other hand, after orthogonal cos phase demodulation by the second phase-sensitive demodulator 26, filtering by the fourth low-pass filter 30, and calculation processing by the fourth controller 31, the third digital-to-analog converter 32 and the third single-ended to differential driving module 13 are fed back to the gyro orthogonal electrodes Q+ and Q-, so as to realize the stable closed-loop control of the gyro orthogonal compensation. Since the driving period of this embodiment accounts for 25% of the entire time-sharing period T, the driving capacity is 0.25 times that of the non-time-sharing under the same conditions, and the driving capacity is relatively weak, which is suitable for the control of the resonant ring micro-electromechanical gyroscope with a large Q value.

Claims

1. A resonant ring micro-electromechanical gyroscope time-sharing digital control system, characterized in that: include: a first modal drive / detection electrode time-sharing switching module, a first modal detection module, a first analog-to-digital converter, a first digital-to-analog converter, a first single-ended to differential drive module, a digital processing unit, a second modal drive / detection electrode time-sharing switching module, a second modal detection module, a second analog-to-digital converter, a second digital-to-analog converter, a second single-ended to differential drive module, a third digital-to-analog converter, and a third single-ended to differential drive module, wherein the digital processing unit includes: a first synchronous detection processing module, a first interpolation filter, a first phase-sensitive demodulator, a first low-pass filter, a second low-pass filter, a first controller, a second controller, a direct digital frequency generation module, a first modulation module, a time-sharing control timing generation module, a second synchronous detection processing module, a second interpolation filter, a second phase-sensitive demodulator, a third low-pass filter, a fourth low-pass filter, a third controller, a fourth controller, and a second modulation module, The positive electrode and negative electrode of the first modal drive / detection electrode of the resonant ring micro-electromechanical gyroscope are respectively connected to the two input and output ends of the first modal drive / detection electrode time-sharing switching module, the first modal detection module, the first analog-to-digital converter, the first synchronous detection processing module, the first interpolation filter, and the first phase-sensitive demodulator are connected in sequence, the first output end of the first phase-sensitive demodulator is connected in sequence with the first low-pass filter and the first modulation module of the first controller, the second output end of the first phase-sensitive demodulator is connected in sequence with the second low-pass filter, the second controller, and the direct digital frequency generation module, and then the direct digital frequency generation module generates two signals of cos and sin, wherein one sin signal is connected to the second modulation module, and the other cos signal is connected to the first modulation module, the output end of the first modulation module is connected to the first digital-to-analog converter, the first single-ended to differential drive module, and the input end of the first modal drive / detection electrode time-sharing switching module, and returns to the first modal drive / detection electrode on the resonant ring micro-electromechanical gyroscope through the first modal drive / detection electrode time-sharing switching module; At the same time, the positive electrode and the negative electrode of the second modal drive / detection electrode on the resonant ring micro-electromechanical gyroscope are respectively connected to the two input and output ends of the second modal drive / detection electrode time-sharing switching module, the second modal drive / detection electrode time-sharing switching module is connected in sequence with the second modal detection module, the second analog-to-digital converter, the second synchronous detection processing module, the second interpolation filter, and the second phase-sensitive demodulator, the first output end of the second phase-sensitive demodulator is connected in sequence with the third low-pass filter, the third controller, the second modulation module, the second digital-to-analog converter, the second single-ended to differential drive module, and the second modal drive / detection electrode time-sharing switching module, and returns to the second modal drive / detection electrode on the resonant ring micro-electromechanical gyroscope through the second modal drive / detection electrode time-sharing switching module, the second output end of the second phase-sensitive demodulator is connected in sequence with the fourth low-pass filter, the fourth controller, the third digital-to-analog converter, and the third single-ended to differential drive module, and the two output ends of the third single-ended to differential drive module are connected to the two orthogonal electrodes of the resonant ring micro-electromechanical gyroscope; One output terminal of the time-sharing control timing generation module is connected to the control terminal of the first-mode drive / detection electrode time-sharing switching module, the control terminal of the second-mode drive / detection electrode time-sharing switching module, the control terminal of the first-mode detection module, and the control terminal of the second-mode detection module; the other output terminal of the time-sharing control timing generation module is connected to the control terminal of the first synchronous detection and processing module and the control terminal of the second synchronous detection and processing module. The time-sharing control timing generation module in the digital processing unit is used to generate the first-mode and second-mode drive and detection time-sharing working control signals S1 and S2, which have the same frequency, so that the gyroscope operates in an alternating mode of a drive period and a detection period.

2. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The control signal S1 generated by the time-sharing control timing generation module in the digital processing unit has two states: high and low. When S1 is in the high state, the first-mode drive / detection electrode time-sharing switching module connects the first single-ended to differential drive module to the first-mode drive / detection electrodes X+ and X-, disconnects the first-mode detection module from the first-mode drive / detection electrodes X+ and X-, and resets the first-mode detection module. At the same time, the second-mode drive / detection electrode time-sharing switching module connects the second single-ended to differential drive module to the second-mode drive / detection electrodes X+ and X-, disconnects the second-mode detection module from the second-mode drive / detection electrodes X+ and X-, and resets the second-mode detection module. The gyroscope is in the drive working period. When S1 is in the low state, the first-mode drive / detection electrode time-sharing switching module disconnects the first single-ended to differential drive module from the first-mode drive / detection electrodes X+ and X-, connects the first-mode detection module to the first-mode drive / detection electrodes X+ and X-. At the same time, the second-mode drive / detection electrode time-sharing switching module disconnects the second single-ended to differential drive module from the second-mode drive / detection electrodes X+ and X-, connects the second-mode detection module to the second-mode drive / detection electrodes X+ and X-. The gyroscope is in the detection working period.

3. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The control signal S2 generated by the time-sharing control timing generation module in the digital processing unit has two states: high and low. Only when S2 is in the high state, the first synchronous detection and processing module and the second synchronous detection and processing module respectively perform integral accumulation processing on the output signals of the first analog-to-digital converter and the second analog-to-digital converter to obtain the instantaneous position detection information of the first mode and the second mode of the gyroscope.

4. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The time-sharing control timing generation module in the digital processing unit generates control signals S1 and S2 in the form of square waves with the same frequency, and the frequency is f s , f s At least 10 times greater than f d , where f d is the gyro drive modal resonant frequency.

5. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 4, characterized in that: The periods of the two control signals S1 and S2 are T, the high-state time of S1 is T1, the low-state time of S1 is T2, the high-state time of S2 is T3, and they satisfy the relationships: 0 < T1 < T, 0 < T2 < T, T1 + T2 = T, 0 < T3 < T2, and the rising edge of S1 coincides with the falling edge of S2.

6. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The first interpolation filter and the second interpolation filter in the digital processing unit change the digital processing sampling frequency of the first mode detection signal and the second mode detection signal from f s Upsample to f clk , effectively reducing the phase noise of the subsequent phase-sensitive demodulation processing, and also has the function of low-pass filtering, where f clk is the operating frequency of the digital processing unit.

7. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The first analog-to-digital converter, the first digital-to-analog converter, the second analog-to-digital converter, and the second digital-to-analog converter all use high-speed converters, and the conversion sampling rate is the same as the operating frequency of the digital processing unit, which is f clk .

8. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The direct digital frequency generation module in the digital processing unit simultaneously generates cosine cos and sine sin AC digital signals according to the signals processed by the first phase-sensitive demodulator, the second low-pass filter, and the second controller, wherein the cos signal is used as the carrier signal of the first modulation module and the second modulation module, and the sin and cos signals are used as the in-phase and quadrature demodulation reference signals of the first phase-sensitive demodulator and the second phase-sensitive demodulator, respectively.

9. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1 and claim 2, characterized in that: The first modulation module and the second modulation module in the digital processing unit normally output modulation signals only when the gyroscope is in the driving working period, and output a normally zero signal in the detection working period.

10. The resonant ring micro-electromechanical gyroscope time-sharing digital control system according to claim 1, characterized in that: The first mode drive and the second mode drive of the gyroscope both adopt differential drive mode, the first mode detection and the second mode detection both adopt differential detection mode, and the differential drive common mode voltage and the differential detection common mode voltage both have a DC voltage difference V with the voltage applied to the gyroscope mass block. DC ,|V DC |>0.

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