CN103303454A - Electric helm gear based on speed ring reversing and control method of electric helm gear - Google Patents

Abstract

The invention provides an electric steering gear device based on speed loop reversing and its control method. The signal conditioning circuit performs voltage conversion, filtering, and amplitude limiting processing on the given signal of the deflection angle of the steering surface, and then sends it to the controller DSP through AD conversion. , the DSP outputs a digital control signal, which is sent to the drive circuit after digital isolation to convert it into a power control signal. By controlling the main power circuit, the brushless DC motor is controlled to work. The brushless DC motor drives the deflection of the rudder surface through the transmission gear set to follow the rudder surface The deflection angle given signal; the bus current of the brushless DC motor is sampled and fed back to the DSP through the current sensor, and the angle sensor connected to the transmission gear set feeds back the current deflection angle of the steering surface in real time and transmits it to the DSP. The invention effectively speeds up the frequency response of the brushless DC electric steering gear and improves the anti-interference performance of the system.

Description

An electric steering gear device based on speed loop commutation and its control method

technical field

The invention relates to a digital electric steering gear device and a control method, in particular to a permanent magnet brushless DC electric steering gear for aircraft.

Background technique

The electric steering gear is a high-precision position servo system. The working principle of the steering gear is to receive the given signal of the rudder surface deflection angle given by the main control computer. After the feedback signal is processed and program adjusted, the deflection of the rudder surface is manipulated by outputting instructions, thereby changing the flight posture or flight trajectory of the aircraft, and finally ensuring that the aircraft flies in the air according to the predetermined trajectory. The electric steering gear is the front-end executive part of the aircraft. During high-speed flight, it must directly bear air friction and resistance, and the working environment is harsh. Under the premise of bearing heavy loads, high and low temperatures, strong vibrations and other harsh conditions, the deflection accuracy must be guaranteed And response speed, the requirements for the core control algorithm are increased.

In recent years, with the rapid development of high-power power electronics technology and rare earth permanent magnet motor technology, electric steering gear technology has developed rapidly and achieved remarkable results. It is gradually replacing traditional hydraulic steering gear and pneumatic steering gear in the small power range. The invention patent "A Digital Steering Gear Controller" with the publication number CN102854814A proposes a digital electric steering gear scheme based on the DSP module, but it only proposes the overall structural scheme of the system. For each functional module of the system and specific The control method is not given in detail. The article "A Permanent Magnet Brushless DC Electric Steering Gear Four-Quadrant Control" published in "Acta Electrotechnical Society" provides an improved electric steering gear control scheme based on current hysteresis control on the basis of PID, but this improvement It is aimed at the suppression of system output torque ripple, and it does not help the most important performance of the electric steering gear, such as deflection accuracy and response speed in a complex working environment.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides an electric steering gear device based on speed loop commutation, which has fast motor response speed and strong anti-interference performance.

The technical solution adopted by the present invention to solve the technical problem is: an electric steering gear device based on speed loop commutation, including signal conditioning circuit, DSP, digital isolation circuit, drive circuit, main power circuit, brushless DC motor, transmission Gear sets, rudder surfaces, current sensors, position sensors and communication circuits. The rudder deflection angle given signal is sent in the form of an analog signal, and the signal conditioning circuit performs voltage conversion, filtering, and limiting processing on it and then sends it to the controller DSP through AD conversion, and the DSP outputs 6 digital control signals, which are digitally isolated Afterwards, it is sent to the drive circuit to convert the power control signal, and the power control signal controls the main power circuit to control the operation of the brushless DC motor. The brushless DC motor drives the deflection of the rudder surface through the transmission gear set to follow the given signal of the deflection angle of the rudder surface; The bus current of the brushless DC motor is sampled and fed back to the DSP by the current sensor to realize the closed-loop control of the current loop; the angle sensor connected to the transmission gear set feeds back the current deflection angle of the rudder surface in real time and transmits it to the DSP to form a closed-loop speed; the current deflection angle of the rudder surface Through the communication circuit, it is transmitted to the upper computer for real-time monitoring.

The present invention also provides a control method for the above device, comprising the following steps:

Step 1: Send the rudder deflection angle analog given signal to the control board, and the signal conditioning circuit performs pre-processing on it, including voltage conversion, filtering and limiting;

Step 2: Send the rudder surface deflection angle analog given signal through AD sampling to the controller DSP as the rudder surface deflection digital given signal;

Step 3: Clear the count variable of the speed loop, use DSP to read the signal of the angle sensor as the digital feedback signal of the rudder deflection angle, and subtract the digital feedback signal of the rudder surface deflection angle from the digital given signal of the rudder surface deflection angle to obtain the position deviation ;

Step 4: Perform position loop PID adjustment, calculate the position loop adjustment output according to the position deviation, and use it as the speed loop setting, the speed loop setting has positive and negative;

Step 5: Clear the current loop counting variable to zero, use the collected rudder surface angle digital feedback signal to calculate the rudder surface speed as the speed feedback, and subtract the speed feedback from the speed loop setting to get the speed deviation;

Step 6: Perform speed PID adjustment, calculate the speed adjustment output according to the speed deviation, and use it as the current loop given signal. The direction of the bus feedback current in this control cycle, add 1 to the count variable of the speed loop;

Step 7: Determine whether the speed loop PID adjustment times have reached the set number n, n≤10, if yes, return to the second step, if not, continue to the eighth step of control;

Step 8: After voltage conversion, filtering and limiting, the collected bus feedback current is sent to DSP through AD sampling, and then multiplied by the sign of the given signal of the current loop in this control cycle to become a vector as the current Loop feedback; then subtract the current feedback from the current loop setting to get the current deviation;

Step 9: Perform current loop PID adjustment, calculate the current loop adjustment output according to the current deviation, and add 1 to the current loop count variable;

Step 10: Transform the output of the current loop adjustment into a duty ratio signal, and the duty ratio signal has positive and negative values;

Step 11: Convert the duty cycle signal into a power control signal through the drive circuit after digital isolation, and send it to the main power circuit, and control the steering surface to deflect according to the control law by controlling the MOSFET on and off in the main power circuit ;

Step 12: Determine whether the number of current loop PID adjustments reaches the set number n, n≤10, if yes, return to step 5, if not, return to step 8 to continue current loop adjustment.

The beneficial effect of the present invention is: the above-mentioned control method of the present invention determines the sign of the bus current collected back in the current control cycle through the sign of the given signal of the current loop in this control cycle, that is, when the bus current is required to be positive, it is considered The feedback current is positive, and the feedback current is considered negative when the required bus current is negative. Since the setting of the current loop is the output of the speed loop, and the positive or negative of the current determines the steering of the brushless DC motor, so this control method that determines the steering of the motor through the output direction of the speed loop is called speed loop commutation method.

Applying this control system to the electric steering gear system has the following advantages compared with the traditional steering gear system: (1) The direction of the electromagnetic torque (that is, the direction of the current) is always consistent with the given direction of the current, and the resulting influence is that the motor speed The direction and the direction of the electromagnetic torque are sometimes inconsistent, which is the braking state. Therefore, in this case, the motor works in a four-quadrant state, which can effectively improve the dynamic response speed of the system; (2) due to the direction given by the current loop Determines the direction of the bus feedback current, so the feedback current can always closely follow the given current, so when an external load is applied to the rudder surface, when the control system requires the current to decrease rapidly, the feedback current can drop rapidly, which is The anti-interference performance of the system is improved, that is, the robustness.

Description of drawings

Figure 1 is a structural diagram of the brushless DC electric steering gear system;

In the figure, 1—signal conditioning circuit, 2—controller DSP, 3—digital isolation circuit, 4—drive circuit, 5—main power circuit, 6—brushless DC motor (BLDCM), 7—transmission gear set, 8— Rudder surface, 9—current sensor, 10—position sensor, 11—RS422 communication.

Figure 2 is a control block diagram of the electric steering gear system.

Detailed ways

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

The technical solution of the present invention includes: controller-DSP, digital isolation circuit, drive circuit, main power circuit, brushless DC motor (BLDCM), transmission gear set, rudder surface, current sensor, position sensor, 422 communication circuit. The rudder deflection angle given signal is sent in the form of an analog signal, and the signal conditioning circuit performs voltage conversion, filtering, and limiting processing on it and then sends it to the controller DSP through AD conversion. The DSP adjusts through the control strategy and outputs 6 digital channels. Control signal, the digital control signal is digitally isolated and then sent to the drive circuit to convert it into a power control signal. The power control signal controls the operation of the brushless DC motor (BLDCM) by controlling the MOSFET in the main power circuit. The motor drives the deflection of the rudder surface through the transmission gear set to follow the given signal of the deflection angle of the rudder surface. The bus current of the brushless DC motor is sampled by the current sensor to realize the closed-loop control of the current loop. The angle sensor (encoder) connected to the transmission gear set feeds back the current deflection angle of the rudder surface in real time, and transmits it to the DSP. The speed is calculated through the current deflection angle to form a closed-loop speed, and the current deflection angle of the rudder surface fed back completes the closed-loop control of the rudder surface position. The current deflection angle of the rudder surface is transmitted to the host computer via RS-422 for real-time monitoring.

In the technical solution of the present invention, the steering gear system control solution adopts position-speed-current three-closed-loop PID control.

The specific control method of the system is as follows:

Step 1: Send the rudder deflection angle analog given signal to the control board, and the signal conditioning circuit performs pre-processing such as voltage conversion, filtering, and clipping;

Step 2: Send the rudder surface deflection angle analog given signal through AD sampling to the controller DSP as the rudder surface deflection digital given signal;

Step 3: Clear the count variable of the speed loop, use DSP to read the signal of the angle sensor (digital encoder) as the digital feedback signal of the rudder deflection angle, and subtract the digital feedback of the rudder surface deflection angle from the digital given signal of the rudder surface deflection angle signal to find the position deviation;

Step 4: Perform position loop PID adjustment, calculate the position loop adjustment output according to the position deviation, and use it as the speed loop setting, the speed loop setting has positive and negative;

Step 5: Clear the counting variable of the current loop to zero, use the digital feedback signal of the rudder deflection angle collected before to calculate the rudder surface speed as the speed feedback, and subtract the speed feedback from the speed loop setting to obtain the speed deviation;

Step 6: Perform speed PID adjustment, calculate the speed adjustment output according to the speed deviation, and use it as the current loop given signal. The direction of the bus feedback current in this control cycle, add 1 to the count variable of the speed loop;

Step 7: Determine whether the number of speed loop PID adjustments reaches n (n≤10) times, if yes, return to the second step, if not, continue to the eighth step of control;

Step 8: After the collected bus feedback current (scalar) is processed by voltage conversion, filtering, and limiting, it is sent to DSP through AD sampling, and then multiplied by the sign of the given signal of the current loop in this control cycle to become vector for current loop feedback. Then subtract the current feedback from the current loop setting to get the current deviation.

Step 9: Perform current loop PID adjustment, calculate the current loop adjustment output (positive or negative) according to the current deviation, and add 1 to the current loop count variable;

Step 10: Transform the output of the current loop regulation into a duty ratio signal, and the duty ratio signal has positive and negative values.

Step 11: Convert the duty cycle signal into a power control signal through the drive circuit after digital isolation, and send it to the main power circuit, and control the steering surface to deflect according to the control law by controlling the MOSFET on and off in the main power circuit ;

Step 12: Determine whether the number of times of current loop PID adjustment reaches n (n≤10), if yes, return to step 5, if not, return to step 8 to continue current loop adjustment.

As shown in Figure 1, the position of the rudder surface is given by analog signal, which is conditioned by the signal conditioning circuit 1 and sent to the controller DSP2 after AD conversion. The DSP realizes the control strategy control and outputs 6 driving signals, which are digitally isolated The circuit 3, the drive circuit 4 and the main power circuit 5 control the work of the brushless DC motor (BLDCM) 6, and the brushless DC motor drives the deflection of the steering surface 8 through the transmission gear set 7 to follow the given position of the steering surface. The bus current of the brushless DC motor is sampled by the current sensor 9 to realize the closed-loop control of the current loop. The position sensor (encoder) 10 connected to the transmission gear set feeds back the current position of the rudder surface in real time and transmits it to the DSP. The rotational speed is calculated through the position signal to form a closed-loop speed, and the position signal fed back completes the closed-loop control of the rudder surface position. The actual measured value of the rudder surface position is transmitted to the host computer via RS-422 communication 11 for real-time monitoring.

As shown in Figure 2, the present invention adopts the classic position-speed-current three-closed-loop PID control, and its specific control process is:

Step 1: Send the rudder deflection angle analog given signal to the control board, and the signal conditioning circuit performs pre-processing such as voltage conversion, filtering, and clipping;

The second step: send the rudder surface deflection angle analog given signal through AD sampling into the controller DSP to be the rudder surface deflection angle digital given signal P ^* ;

Step 3: Clear the counting variable Vcnt of the speed loop, use DSP to read the signal of the angle sensor (digital encoder) as the digital feedback signal P of the rudder surface deflection angle, and subtract the rudder surface from the digital given signal P ^* of the rudder surface deflection angle Calculate the position deviation ΔP by using the deflection angle digital feedback signal P;

Step 4: Perform position loop PID adjustment, calculate the position loop adjustment output according to the deviation ΔP, and use it as the speed loop given V ^* , V ^* has positive and negative;

Step 5: Clear the current loop count variable Icnt to zero, use the digital feedback signal of the rudder deflection angle collected before to calculate the rudder surface speed V as the speed feedback, and subtract the speed feedback V from the speed loop given V ^* to get the speed deviation ΔV;

Step 6: Perform speed loop PID adjustment, calculate the speed adjustment output according to the speed deviation ΔV, and use it as the current loop given I ^* _(k) , I ^* _(k) has positive or negative, add the speed loop count variable Vcnt 1;

Step 7: Determine whether the number of speed loop PID adjustments reaches n (n≤10) times, if yes, return to the second step, if not, continue to the eighth step of control;

计算得到I作为电流反馈，其中I^* _(k)表示本控制周期的电流环给定，即速度环输出，I^* _(k)有正负，表示I^* _(k)的符号。然后用电流给定I^*减去电流反馈I得到电流偏差ΔI。Step 8: Send the collected bus current I ₀ to DSP through AD after signal conditioning, and then pass the formula

Calculate I as current feedback, where I ^* _(k) represents the current loop setting of this control cycle, that is, the speed loop output, I ^* _(k) has positive and negative, Denotes the notation for I ^* _(k) . Then subtract the current feedback I from the given current I ^* to obtain the current deviation ΔI.

Step 9: Perform current loop PID adjustment, calculate the current adjustment output (positive or negative) according to the current deviation ΔI, and add 1 to the current loop count variable Icnt;

Step 10: Transform the output of the current loop adjustment into a duty ratio signal D, and D has positive and negative values.

Step 11: Convert the duty cycle signal into a power control signal through the drive circuit after digital isolation, and send it to the main power circuit, and control the steering surface to deflect according to the control law by controlling the MOSFET on and off in the main power circuit ;

Step 12: Determine whether the number of current loop PID adjustments reaches n (n≤10) times, if yes, return to step 5, if not, return to step 8 to continue current loop adjustment;

The present invention determines the positive or negative of the bus feedback current through the positive or negative output of the speed loop. When the bus current is required to be positive, the feedback current is considered to be positive, and when the bus current is required to be negative, the feedback current is considered to be negative, so as to realize the speed loop change direction.

Claims (2)

1. electric steering gear device based on speed ring commutation, comprise signal conditioning circuit, DSP, the numeral buffer circuit, driving circuit, main power circuit, brshless DC motor, driving gear set, rudder face, current sensor, position transduser and communication circuit, it is characterized in that: the given signal in rudder face drift angle is sent into the form of analog signal, signal conditioning circuit carries out voltage transformation with it, filtering, amplitude limiting processing is sent into controller DSP by the AD conversion, DSP exports 6 way word control signals, after numeral is isolated, give driving circuit and convert power control signal to, power control signal is by the main power circuit of control, thereby the work of control brushless direct current motor, brshless DC motor drives control surface deflection to follow the given signal in rudder face drift angle by driving gear set; The bus current of brshless DC motor to DSP, is realized the electric current loop closed loop control through the current sensor sampling feedback; The angular transducer that links to each other with driving gear set feeds back the current drift angle of rudder face in real time, passes to DSP, forms speed closed loop; The current drift angle of rudder face is passed to upper computer through communication circuit and is monitored in real time.

2. a control method of utilizing the described device of claim 1 is characterized in that comprising the steps:

The first step: give control desk with rudder face drift angle simulate given signal, signal conditioning circuit carries out early stage to it to be handled, and comprises voltage transformation, filtering and amplitude limit;

Second step: will send into controller DSP by the AD sampling through the rudder face drift angle simulate given signal of handling early stage is the given signal of rudder face drift angle numeral;

The 3rd step: with the zero clearing of speed ring counting variable,, deduct rudder face drift angle digital feedback signal with the rudder face drift angle given signal of numeral and obtain position deviation as rudder face drift angle digital feedback signal with DSP reading angular sensor signal;

The 4th step: carry out position ring PID and regulate, calculate position ring according to position deviation and regulate output, and it is given as speed ring, speed ring is given have positive and negative;

The 5th step: with the zero clearing of electric current loop counting variable, utilize the rudder face drift angle digital feedback signal of gathering to calculate the rudder face rotating speed as velocity feedback, obtain velocity deviation with the given velocity feedback that deducts of speed ring;

The 6th step: carry out speed by PID and regulate, calculate speed according to velocity deviation and regulate output, and with it as the given signal of electric current loop, the given signal of electric current loop has positive and negative, the sign of the given signal of record current ring, to determine the direction of this control cycle bus feedback current, the speed ring counting variable is added 1;

The 7th step: judge that speed ring PID regulates number of times and whether reaches set point number n, n≤10, if, then returned for second step, if not, then continue down to carry out the control of the 8th step;

The 8th step: through sending into DSP by the AD sampling behind voltage transformation, filtering and the amplitude limit, the symbol with the given signal of electric current loop of this control cycle multiplies each other then, becomes vector, to feed back as electric current loop with the bus feedback current of gather; Obtain current deviation with the given current feedback that deducts of electric current loop then;

The 9th step: carry out electric current loop PID and regulate, calculate electric current loop according to current deviation and regulate output, the electric current loop counting variable is added 1;

The tenth step: electric current loop is regulated output be transformed into duty cycle signals, duty cycle signals has positive and negative;

The 11 step: duty cycle signals is isolated the back through numeral converts power control signal to by driving circuit, give main power circuit, by control MOSFET in the main power circuit turn on and off control rudder face by control law deflection;

The 12 step: judge that electric current loop PID regulates number of times and whether reaches set point number n, n≤10, if, then returned for the 5th step, if not, then returned for the 8th step and proceed the electric current loop adjusting.

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