A kind of Embedded Ultrasonic motor double freedom platform driving governor
Technical field
The present invention relates to the driver that a kind of control is applied to double freedom ultrasound electric machine platform and can realize the hardware configuration of high-performance, high accuracy speed stability and the software control method that is complementary with it, belong to Driven by Ultrasonic Motors control field.
Background technology
Ultrasound electric machine is that a kind of piezoelectric ceramic start excites the elastomer resonance mode to produce the periodicity row ripple of submicron order distortion, again the motor by friction working.Compare characteristics such as ultrasound electric machine has the slow-speed of revolution, moment/mass ratio is big, response speed is fast, power failure self-locking, nanometer resolution, no electromagnetic interference with conventional motors.Adopt the quick track and localization of high accuracy that the double freedom platform of two ultrasound electric machines can implementation platform, have broad application prospects in fields such as biomedical, semiconductor packages and Aero-Space.
Ultrasound electric machine need provide the supersonic frequency of two-way quadrature phase to come driving work by the Driven by Ultrasonic Motors device.Adopt the double freedom platform of two ultrasound electric machines, tradition adopts two drivers to drive two ultrasound electric machines respectively, the ultrasound electric machine of a driver control one degree of freedom (X-direction), and the ultrasound electric machine of another degree of freedom of another driver control (Y-direction), and then come the collecting sensor signal of implementation platform and location to follow the tracks of control with a microcontroller, make that on the whole platform driving control system volume ratio is bigger, be difficult for realizing the control strategy of frequency modulation, pressure regulation and phase modulation combination, at the bottom of the control algolithm efficient, and the failure rate height.Use employing of the present invention can control real-time interlock and the Collaborative Control of X-direction, Y-direction platform ultrasound electric machine simultaneously based on the ultrasound electric machine double freedom platform driving governor of monolithic dsp chip, the control circuit structure is simple relatively, cost is lower, use a DSP, there is not the synchronism problem, control precision is higher, is more conducive to the integrated of drive circuit, miniaturization.The double-deck closed loop feedback control of motor is conducive to more realize that high accuracy and high-resolution platform drive nanometer positioning.
Summary of the invention
Technical problem
The technical problem to be solved in the present invention provides a kind of driving governor that adopts embedded microprocessor DSP control ultrasound electric machine double freedom platform, and it can control two ultrasound electric machines of platform X-direction and Y-direction simultaneously by four groups of EPWM signals of a dsp chip.
Technology contents
In order to solve above-mentioned technical problem, Embedded Ultrasonic motor double freedom platform driving governor of the present invention comprises external crystal-controlled oscillation input unit, embedded microprocessor and power amplification and matching unit, and the clock signal that described external crystal-controlled oscillation input unit sends is dispensed to an EPWM module, the 2nd EPWM module, the 3rd EPWM module and the 4th EPWM module through the EPWM clock unit in the embedded microprocessor;
The output signal of a described EPWM module is handled the back to first ultrasound electric machine generation to be controlled, the first driving signal through first power amplification in power amplification and the matching unit and matching module;
The output signal process power amplification of described the 2nd EPWM module and second power amplification in the matching unit and matching module are handled the back and are produced the second driving signal to first ultrasound electric machine to be controlled, and it is 90 ° that the described second driving signal and first drives signal phase difference;
The output signal of described the 3rd EPWM module produces the 3rd driving signal through the 3rd power amplification in power amplification and the matching unit and matching module processing back to second ultrasound electric machine to be controlled;
The output signal of described the 4th EPWM module produces the moving signal of 4 wheel driven through the 4th power amplification in power amplification and the matching unit and matching module processing back to second ultrasound electric machine to be controlled, and it is 90 ° that the moving signal of described 4 wheel driven and the 3rd drives signal phase difference.
Described crystal oscillator, EPWM module, power amplification and matching module, ultrasound electric machine, feedback signal shaping and rotating compensating module and amplifier comparator have been formed closed-loop system, realize the continuous variable adjusting of motor-driven frequency, realized the control of high-performance rotating speed.
Further, also comprise signal feedback compensation deals unit, described signal feedback compensation deals unit comprises the first feedback signal shaping and rotating compensating module, the second feedback signal shaping and rotating compensating module and speed regulation unit, and described speed regulation unit comprises the first speed adjustment module and second speed adjustment module;
Further, the lonely utmost point feedback signal of the running status of first ultrasound electric machine to be controlled is handled the back input first amplifier comparator module inverting input by the described first feedback signal shaping and rotating compensating module, the output signal of the first speed adjustment module is imported the first amplifier comparator module in-phase input end, the ADC module in the output signal input embedded microprocessor of the first amplifier comparator module;
Further, the lonely utmost point feedback signal of the running status of second ultrasound electric machine to be controlled is handled the inverting input of the back input second amplifier comparator module by the described second feedback signal shaping and rotating compensating module, the output signal of second speed adjustment module is imported the in-phase input end of the second amplifier comparator module, the ADC module in the output signal input embedded microprocessor of the second amplifier comparator module.
Further, the described first feedback signal shaping and rotating compensating module switch by the rotating velocity compensation of carrying out of first switch; The described second feedback signal shaping and rotating compensating module switch by the rotating velocity compensation of carrying out of second switch.First, second feedback signal shaping and rotating compensating module can be realized the rotating velocity compensation automatically according to the state of switch.
Further, in described first power amplification and matching module, second power amplification and matching module, the 3rd power amplification and matching module and the 4th power amplification and the matching module, the two-way of extraneous input drives and boosts through a step-up transformer after signal is recommended amplification through two MOSFET pipes respectively again, and is after-applied in motor to be controlled by an inductance coupling in parallel again.
Further, in described first power amplification and matching module, second power amplification and matching module, the 3rd power amplification and matching module and the 4th power amplification and the matching module, be provided with pulse absorption circuit between described MOSFET pipe and the step-up transformer.
Further, after the voltage feedback signal that the described first feedback signal shaping and rotating compensating module and the second feedback signal shaping and rotating compensating module produce the lonely utmost point of motor is handled, modulus sampling unit and motor positive and inverse regulating circuit in the signal difference input microprocessor of output.
In the Embedded Ultrasonic motor double freedom platform driving governor of the present invention, detected motor speed, position, direction signal are imported the EQEP module of dsp chip by two encoders through peripheral interface circuit, utilize DSP powerful operation capacity corresponding control algolithm in real time in addition again, X-Y platform is realized more accurate closed-loop control, the performance complement of implementation platform mechanical system and circuit control system.
It is the core driving control system that the embedded motor double freedom platform driving governor of overfulfiling a production target of the present invention has adopted based on dsp chip, the Harvard structure that the inner employing program of dsp chip and data are separated, have special hardware multiplier, can be used for realizing fast various digital signal processing algorithms.
Beneficial effect
Embedded Ultrasonic motor double freedom platform driving governor of the present invention, realize real-time continuously frequency signal adjusting by the microprocessor internal module, reached the control target to platform motor high-performance, high stability, and realize that by the programming to embedded bit processor motor driver and host computer communicate, thereby can realize the reception of remote control commands and the real-time monitoring of motor operating state; Can control the real-time interlock of X-direction, Y-direction platform ultrasound electric machine simultaneously, the control circuit structure is simple relatively, and cost is lower.Only use a DSP, do not have the synchronism problem, control precision is higher, is more conducive to the integrated of drive circuit, miniaturization.
Description of drawings
Fig. 1 is Embedded Ultrasonic motor double freedom platform driving governor schematic diagram of the present invention;
Fig. 2 is that power amplification and mesh power amplify and the matching module circuit is realized schematic diagram;
Fig. 3 is that feedback signal is regulated and rotating compensation principle figure;
Fig. 4 is that the driving with the single-degree-of-freedom ultrasound electric machine is the schematic diagram of embodiment.
Embodiment
Below in conjunction with accompanying drawing technical scheme of the present invention is further specified.
As shown in Figure 1, the Embedded Ultrasonic motor double freedom platform driving governor of present embodiment comprises external crystal-controlled oscillation input unit 1, embedded microprocessor 19 and power amplification and matching unit, and the clock signal that described external crystal-controlled oscillation input unit 1 sends is dispensed to an EPWM module 3, the 2nd EPWM module 4, the 3rd EPWM module 5 and the 4th EPWM module 6 through the EPWM clock unit 2 in the embedded microprocessor 19;
The output signal of a described EPWM module 3 is handled the back to first ultrasound electric machine, 11 generations, the first driving signal to be controlled through first power amplification in power amplification and the matching unit and matching module 7;
The output signal process power amplification of described the 2nd EPWM module 4 and second power amplification in the matching unit and matching module 8 are handled the back and are produced the second driving signal to first ultrasound electric machine 11 to be controlled, and it is 90 ° that the described second driving signal and first drives signal phase difference;
The output signal of described the 3rd EPWM module 5 is handled the back to second ultrasound electric machine, 12 generations the 3rd driving signal to be controlled through the 3rd power amplification in power amplification and the matching unit and matching module 9;
The output signal of described the 4th EPWM module 6 is handled the back to the moving signal of second ultrasound electric machine, 12 generation 4 wheel drivens to be controlled through the 4th power amplification in power amplification and the matching unit and matching module 10, and it is 90 ° that the moving signal of described 4 wheel driven and the 3rd drives signal phase difference.
It also comprises signal feedback compensation deals unit, described signal feedback compensation deals unit comprises the first feedback signal shaping and rotating compensating module 13, the second feedback signal shaping and rotating compensating module 14 and speed regulation unit, and described speed regulation unit comprises the first speed adjustment module 17 and second speed adjustment module 18;
The lonely utmost point feedback signal of the running status of first ultrasound electric machine 11 to be controlled is handled the back input first amplifier comparator module 15 inverting inputs by the described first feedback signal shaping and rotating compensating module 13, the output signal of the first speed adjustment module 17 is imported the first amplifier comparator module, 15 in-phase input ends, the ADC module in the output signal input embedded microprocessor 19 of the first amplifier comparator module 15;
The lonely utmost point feedback signal of the running status of second ultrasound electric machine 12 to be controlled is handled the inverting input of the back input second amplifier comparator module 16 by the described second feedback signal shaping and rotating compensating module 14, the output signal of second speed adjustment module 18 is imported the in-phase input end of the second amplifier comparator module 16, the ADC module in the output signal input embedded microprocessor 19 of the second amplifier comparator module 16.
The described first feedback signal shaping and rotating compensating module 13 carry out the rotating velocity compensation by first switch 20 and switch;
The described second feedback signal shaping and rotating compensating module 14 carry out the rotating velocity compensation by second switch 21 and switch.
In described first power amplification and matching module 7, second power amplification and matching module 8, the 3rd power amplification and matching module 9 and the 4th power amplification and the matching module 10, the two-way of extraneous input drives and boosts through a step-up transformer after signal is recommended amplification through two MOSFET pipes respectively again, and is after-applied in motor to be controlled by an inductance coupling in parallel again.In described first power amplification and matching module 7, second power amplification and matching module 8, the 3rd power amplification and matching module 9 and the 4th power amplification and the matching module 10, be provided with pulse absorption circuit between described MOSFET pipe and the step-up transformer.Being example with one of them power amplification and matching module circuit, as shown in Figure 2, is that example is illustrated with the driving of X-direction ultrasound electric machine, and the driving of another Y-direction ultrasound electric machine therewith roughly the same.The two-phase of motor drives and adopts the push-pull type power amplification.Wherein, Sin phase two-way driving signal is recommended amplification by MOSFET pipe Q1 and Q2 and boosted by transformer T1, and is after-applied in motor by shunt inductance L1 coupling again; Cos phase two-way driving signal is recommended amplification by MOSFET pipe Q3 and Q4 and boosted by transformer T2, and is after-applied in motor by shunt inductance L2 coupling again.Diode D3, D4, D5, D6 and resistance R 23 and capacitor C 2 are formed pulse absorption circuit.
After the voltage feedback signal that the lonely utmost point of 14 pairs of motors of the described first feedback signal shaping and rotating compensating module 13 and the second feedback signal shaping and rotating compensating module produces is handled, modulus sampling unit and motor positive and inverse regulating circuit in the signal difference input microprocessor of output.As shown in Figure 3, the voltage feedback signal that produces of the lonely utmost point of motor is through the laggard modulus sampling of going into microprocessor of R21, D7, C19, R22, R23, VR1, D8, R24, C20, R25 and R26.R27, R27, R29, R30, Q5, Q6 and VR2 have formed the motor positive and inverse regulating circuit.
As shown in Figure 4, be that example is specifically described technical scheme of the present invention with the driving of X-direction ultrasound electric machine, the driving of another Y-direction ultrasound electric machine is therewith roughly the same.When adopting embedded microprocessor DSP, the hardware resource configuration is as follows: the signal that external crystal-controlled oscillation 1 produces enters by the digital input pin of DSP, enter the EPWM module 3 and 4 in two band dead bands simultaneously, EPWM module 3 and 4 configures frequency dividing ratio, duty ratio and dead band size in initialization, and the initial phase that EPWM module 3 is set is 0 °, the initial phase of EPWM module 4 is 90 °, and the clock signal of two EPWM modules is synchronous, be that clock is flowed into by EPWM module 3, flow out again through the EPWM4 module.If receive 1CW that switch 20 provides or 1CCW signal then enable EPWM output, thereby its digital output pin produces SinA, SinB, CosA and CosB four tunnel motor drive signal to power amplification circuit, as not receiving 1CW or 1CCW signal, then the EPWM output pin is low level.For lonely utmost point feedback ultrasound electric machine is arranged, the signal of the reaction motor operation operating state that its operation back produces at the lonely utmost point in Fig. 3 after the processing circuit processes through R2 and C2, then by operational amplifier 15 negative terminals, the voltage ratio that this signal and speed adjustment module 17 produce, and produce a voltage control signal after the analog pid adjuster computing that forms via R1, C1, R2 and C2, form a speed closed loop regulating loop thereby receive the output frequency of regulating EPWM via the ADC module of DSP inside again.
After driver powered up, relay indicating light was with higher visible frequency scintillation when microprocessor was received CW that switch 7 provides or CCW signal, and expression embedded microprocessor DSP is working properly and motor drive signal output arranged.