CN104590362A - Control device and controller for electric power steering system based on alternating current asynchronous motor - Google Patents

Abstract

The invention relates to a control device and a controller for an electric power steering system based on an alternating current asynchronous motor. The control device establishes a steering wheel torque rotation angle signal acquisition circuit, a motor rotor position signal acquisition circuit, an alternating current asynchronous motor driving circuit and a CAN communication circuit with a main control chip as the core. The controller comprises an electric power steering control module, an alternating current asynchronous motor control module, a motor rotor position signal resolving module and a steering wheel torque rotation angle signal resolving module, wherein the electric power steering control module comprises a multipoint fold line type basic power control sub-module, a motor compensation control sub-module, an active return control sub-module and a motor q-axis direction target current calculation sub-module. The control device and the controller achieves good control over the electric power steering system based on the alternating current asynchronous motor through a reasonable architecture of a control hardware platform and control software, and enables the electric power steering system to be more reliable and complete.

Description

Based on electric boosting steering system control setup and the controller of AC induction motor

Technical field

The invention belongs to Vehicular turn control technology field, particularly a kind of electric boosting steering system control setup based on AC induction motor and controller.

Background technology

As the product that Eltec combines with steering swivel system, electric power steering EPS (ElectricPower Steering) directly relies on motor to provide assisted diversion moment.Compared with traditional hydraulic power-assist steering system HPS (hydraulic power steering), EPS can effectively reduce engine fuel consumption, improve the cornering properties of vehicle, improve the active safety of automobile, shorten the advantages such as vehicle coupling time-to-market.

The development of current electric boosting steering system includes following feature: first, for solving owing to there being brushless motor to there is the problems such as brush-commutated life-span of bringing and electromagnetic interference, in electric boosting steering system, assist motor is by having brushless motor gradually to alternating current dynamo transition.Secondly, also just the putting forth effort of middle and high end electric boosting steering system product improves its control policy relevant, if basic assist characteristic is by simple linear pattern power assist control method, towards can be more excellent raising chaufeur feel and vehicle handling stability control method development; Add initiatively rotary transform tensor strategy and improve the return performance of vehicle; To steering swivel system friction, damping and inertia compensate control etc.In addition, steering swivel system torque rotary angle transmitter is towards the future development of contactless, high precision, high noise immunity.The application of these new equipment and method can improve the Performance And Reliability of electric boosting steering system greatly, but causes whole system more complicated simultaneously, adds design difficulty.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of realization simply, can meet the electric boosting steering system control setup based on AC induction motor and the controller of vehicle low speed portability and high stability when turning to.

In order to solve the problems of the technologies described above, electric boosting steering system control setup based on AC induction motor of the present invention comprises main control chip, rotor incremental counter signal acquisition circuit, steering wheel torque angular signal Acquisition Circuit, ACasynchronous motor drive circuit and CAN communication circuit, in described rotor incremental counter signal acquisition circuit, the rotor-position signal of the AC induction motor of rotor-position sensor collection have passed through RC filter circuit successively and twice negater circuit being made up of Schmidt trigger accesses main control chip, in steering wheel torque angular signal Acquisition Circuit, the steering wheel torque angular signal of steering wheel torque rotary angle transmitter collection have passed through RC filter circuit and operational amplification circuit access main control chip successively, in ACasynchronous motor drive circuit, drive singal after sending from main control chip successively through bus transceiver, driving chip, high-side switch signal is wherein being boosted by bootstrap circuit after driving chip, then three phase full bridge power circuit is accessed, low side switch signal is directly accessing three phase full bridge power circuit after driving chip, three phase full bridge power circuit output signal drives AC induction motor to run, the current signal that two current sensors that AC induction motor phase line is installed produce enters main control chip through RC filter circuit and operational amplification circuit, a CAN communication transceiver is added between CAN and main control chip.

Electric booster steering system controller based on AC induction motor of the present invention comprises:

Motor rotor position signal resolves module: convert the motor rotor position signal of rotor incremental counter signal acquisition circuit collection to rotor tach signal;

Steering wheel torque angular signal resolves module: export to electric power steering control module after carrying out filtering process to the torque angular signal of steering wheel torque angular signal Acquisition Circuit collection;

Electric power steering control module: comprise basic Power assisted control submodule, motor compensating control submodule, initiatively rotary transform tensor submodule and motor q direction of principal axis target current calculating sub module;

Basic Power assisted control submodule: the current vehicle speed signal V of reception CAN communication circuit transmission, steering wheel torque angular signal resolve the steering wheel torque T of module transfer _s, according to the multiple spot broken line basic power-assisted curve determination current vehicle speed signal V and steering wheel torque T prestored _scorresponding basic Power assisted control electric current I _b; Wherein multiple spot broken line basic power-assisted curve preparation method is as follows:

N section is divided into: V by ascending for the speed of a motor vehicle ₁~ V ₂, V ₂~ V ₃..., V _n-1~ V _n, be greater than V _n; Each section of correspondence steering wheel torque, to basic power-assisted electric current multiple spot broken line, is [T corresponding to the steering wheel torque of n-th section of speed of a motor vehicle to M unique point on basic power-assisted electric current multiple spot broken line _sn1, I _bn1], [T _sn2, I _bn2] ..., [T _sn8, I _bn8], [T _snM, I _bnM], n=1,2 ... N; The steering wheel torque then corresponding to n-th section of speed of a motor vehicle in multiple spot broken line basic power-assisted curve is expressed as basic power-assisted electric current multiple spot broken line:

$I_b=\left\{\begin{array}{cc}\frac{I_{\mathrm{bn}2}-I_{\mathrm{bn}1}}{T_{\mathrm{sn}2}-T_{\mathrm{sn}1}}(T_s-T_{\mathrm{sn}1})+I_{\mathrm{bn}1}& T_{\mathrm{sn}1}\&le;T_s<T_{\mathrm{sn}2}\\ \frac{I_{\mathrm{bn}3}-I_{\mathrm{bn}2}}{T_{\mathrm{sn}3}-T_{\mathrm{sn}2}}(T_s-T_{\mathrm{sn}2})+I_{\mathrm{bn}2}& T_{\mathrm{sn}2}\&le;T_s<T_{\mathrm{sn}3}\\ \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;\\ \frac{I_{\mathrm{bnM}}-I_{\mathrm{bn}}(M-1)}{T_{\mathrm{snM}}-T_{\mathrm{sn}(M-1)}}(T_s-T_{\mathrm{sn}(M-1)})+I_{\mathrm{bn}(M-1)}& T_{\mathrm{sn}(M-1)}\&le;T_s<T_{\mathrm{snM}}\\ I_{\mathrm{bnM}}& T_{\mathrm{snM}}\&le;T_s\end{array}\right.---\left(1\right)$

Motor compensating controls submodule: calculate motor compensating according to formula (2) and control electric current I _c;

I _c＝I _f+I _d+I _i(2)

Wherein I _ffor friciton compensation controls electric current, k _fit is friciton compensation coefficient; I _dfor damping compensation controls electric current, k _dit is damping compensation coefficient; I _ifor inertia compensatory control electric current k _iit is inertia compensating factor; θ is the motor corner calculated according to steering wheel angle signal θ s;

Initiatively rotary transform tensor submodule: as steering wheel torque T _sabsolute value be less than a definite value T _sr, and steering wheel angle θ _sabsolute value be greater than a definite value θ _srtime enter back positive current control; Target direction dish corner is set as 0 °, by bearing circle rotational angle theta _scarry out PID control, obtain back positive current, and under different vehicle velocity V, the maxim and minimum value of returning positive current are limited thus obtain rotary transform tensor electric current I _r; Wherein in different vehicle velocity V, the maxim of positive current and minimum value obtain by tabling look-up next time; :

Motor q direction of principal axis target current calculating sub module: calculate the axial target current I of motor q according to formula (3) _qref:

I _qref＝I _b+I _c+I _r(3)

AC induction motor control module: converted motor three phase current I by Clark conversion and Park _a, I _band I _cbe converted to motor d direction of principal axis actual current I _dactual current I axial with q _q; By axial for motor d target current I _drefbe set as 0, target current I _drefwith motor d direction of principal axis actual current I _denter d shaft current PID after subtracting each other to control; The axial target current I of the motor q obtained by electric power steering control module _qrefactual current I axial with motor q _qenter q shaft current PID after subtracting each other to control; D shaft current PID control and q shaft current PID control the motor d direction of principal axis target voltage U obtained respectively _drefwith motor q direction of principal axis target voltage U _qrefmotor α direction of principal axis target voltage U is obtained through Park inverse transformation _{α ref}with motor β direction of principal axis target voltage U _{β ref}; Method output motor finally by Using dSPACE of SVPWM and seven segmentations controls each binistor duty cycle signals.

Present invention employs electric boosting steering system based on AC induction motor as control object, electric boosting steering system controls to contain hardware platform and control software design.

On a hardware platform, the present invention, with Master control chip, constructs steering-wheel torque angular signal Acquisition Circuit, motor rotor position Acquisition Circuit, ACasynchronous motor drive circuit and CAN communication circuit.

For described electric boosting steering system, construct the Control Soft in Electric Power Steering based on AC induction motor.Control software design of the present invention includes electric power steering control program, AC induction motor control program, rotor rotating speed solver and steering-wheel torque angular signal solver four parts.

Electric power steering control program includes the basic Power assisted control of multiple spot broken line, motor compensating controls and active rotary transform tensor.Adopt the basic Power assisted control of multiple spot broken line, its power-assisted curve smoothing, realize simple, be convenient to amendment and debugging.Motor compensating controls to include that friciton compensation controls, damping compensation controls and inertia compensatory control, improves the system friction, dumping force and the force of inertia that increase owing to adding motor and speed reducer structure in steering swivel system to the impact turning to feel.Active rotary transform tensor can improve vehicle low speed and return positive deficiency, returns positive over control at a high speed, makes vehicle obtain good steering reversal performance.

AC induction motor control program adopts the vector control method had compared with high dynamic response characteristic, three phase current based on stationary stator is converted to the biphase current based on rotor by coordinate transform, realizes the electric current of excitation direction and the decoupling zero of torque current.The switching time of each binistor is produced finally by space pulse width vector modulation method and seven segmentation methods.

In order to realize the decoupling zero of electric current at excitation direction and torque direction, need the position knowing motor magnetic flux, this needs the velocity information accurately obtaining rotor speed.Velocity information is measured by the incremental encoder be connected on rotor shaft (i.e. rotor-position sensor), and the motor rotor position signal in recycling main control chip resolves module converts and becomes rotor speed.

Steering-wheel torque angular signal solver carries out simple filtering process to torque angular signal.

The present invention, by achieving the excellent control to the electric boosting steering system based on AC induction motor to the Rational of control hardware platform and control software design, makes electric boosting steering system more reliably perfect.

Accompanying drawing explanation

Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.

Fig. 1 is the electric boosting steering system control setup schematic diagram based on AC induction motor of the present invention.

Fig. 2 is the electric booster steering system controller structured flowchart based on AC induction motor of the present invention.

Fig. 3 is electric power steering control module block diagram.

Fig. 4 is the basic power-assisted curve synoptic diagram of multiple spot broken line.

In Fig. 1: 1. main control chip; 2. bus transceiver; 3. driving chip; 4. bootstrap circuit; 5. three phase full bridge power circuit; 6. AC induction motor; 7. current sensor; 8.RC filter circuit; 9. operational amplification circuit; 10. rotor-position sensor; 11.RC filter circuit; Twice negater circuit that 12. Schmidt triggers are formed; 13. steering wheel torque rotary angle transmitters; 14.RC filter circuit; 15. operational amplification circuits; 16.CAN bus; 17.CAN communications transceiver.

In Fig. 2: 6. AC induction motor; 10. rotor-position sensor; 13. steering wheel torque rotary angle transmitters.

Detailed description of the invention

As shown in Figure 1, the digital signal processor TMS320F2812 that produces for TIX of main control chip 1 of the present invention.The present invention take TMS320F2812 as core design rotor incremental counter signal acquisition circuit, steering wheel torque angular signal Acquisition Circuit, ACasynchronous motor drive circuit and CAN communication circuit.

In rotor incremental counter signal acquisition circuit, rotor-position sensor 10 adopts incremental encoder, and this coder is installed in the rotating shaft of AC induction motor 6.

The motor rotor position signal of rotor incremental counter signal acquisition circuit rotor position transduser collection have passed through twice negater circuit 12 that RC filter circuit 11 and Schmidt trigger are formed successively, plays and eliminates radio-frequency interference, signal shaping, signal is converted to the effect of 3.3V by 5V.Motor rotor position signal HALLa accesses master control GPIOB0 pin, and HALLb accesses master control GPIOB1 pin, and HALLc accesses master control GPIOB2 pin, and QEP1 accesses master control QEP4 pin, and QEP2 accesses master control QEP5 pin.

In ACasynchronous motor drive circuit, drive singal is first through bus transceiver 2 (adopting model to be the transceiver of 74HC245), plays and drive singal is converted to 5V by 3.3V, is improved the effect of drive singal load-carrying capacity, isolated drive circuit and main control chip 1.Then three road high-side switch signal PWM1, PWM3, PWM5 access HIN1, HIN2, HIN3 of driving chip 3 (adopting model to be the driving chip of IR2130) respectively, and three road low side switch signal PWM2, PWM4, PWM6 access LIN1, LIN2, LIN3 of driving chip 3 respectively.Drive singal, after driving chip 3, after high-side switch signal demand boosts further across bootstrap circuit 4, controls three phase full bridge power circuit 5 and drives AC induction motor 6 to run.Because AC induction motor 3 winding is star connection, three phase current and be zero, so only need gather two-way phase current.Installation two current sensors 7 from AC induction motor phase line A, B.The current signal that current sensor 7 sends, through RC filter circuit 8 and operational amplification circuit 9, plays filtering radio-frequency interference and 5V signal is converted to the effect of 3V.Current analog signal enters ADINA1 and the ADINA2 pin of main control chip 1 afterwards.

Main control chip 1, bus transceiver 2, driving chip 3 are not limited to above-mentioned model, and main control chip 1 can also adopt other to have the chip of digital signal processing capability, and bus transceiver 2, driving chip 3 can also adopt device and the chip of other models.

CAN_H and CAN_L of CAN is connected on a CAN communication transceiver 17 in CAN communication circuit, then accesses on CANTXA and the CANRXA pin of main control chip 1.

As shown in Figure 2, the control software design of main control chip 1 of the present invention mainly includes four parts: electric power steering control program, AC induction motor control program, rotor rotating speed solver and steering wheel torque angular signal solver, corresponding to four modules: motor rotor position signal resolves module, steering wheel torque angular signal resolves module, electric power steering control module, AC induction motor control module.

Main control chip 1 resolves the steering wheel torque corner information that obtains by gathering and obtains the axial target current of AC induction motor q by the speed information that CAN obtains by electric boosting steering system control program.Actual current and the collection of this AC induction motor q direction of principal axis target current, AC induction motor three phase lines being resolved together with the AC induction motor rotor position information obtained is input in AC induction motor control module, output drive signal, then by driving circuit, final realization controls the power-assisted square required for motor output.

Motor rotor position signal resolves module: catch the code-disc signal of rotor-position sensor (incremental encoder) and convert thereof into rotor speed;

Steering wheel torque angular signal resolves module: export to electric power steering control module after carrying out filtering process to the torque angular signal of steering wheel torque rotary angle transmitter collection.

Fig. 3 is electric power steering control module structured flowchart of the present invention.Electric power steering control module includes four parts: basic Power assisted control submodule, motor compensating control submodule, initiatively rotary transform tensor submodule and motor q direction of principal axis target current calculating sub module.Wherein, the size of basic Power assisted control generation current is relevant with vehicle velocity V to steering wheel torque Ts, and power-assisted curve is determined to take into account ease of steering and road-holding property.Motor compensating controls to reduce or offset the friction force, dumping force and the force of inertia that produce because steering swivel system adds motor and speed reducer structure, improves electric boosting steering system dynamic response effect.Active rotary transform tensor can improve vehicle low speed and return positive deficiency, returns positive over control at a high speed, makes vehicle obtain good steering reversal performance.Basic Power assisted control electric current I _b, motor compensating controls electric current I _c, rotary transform tensor electric current I _r, this three portion of electrical current sum constitutes motor q axle target current I _qref.

The current vehicle speed signal V of basic Power assisted control submodule reception CAN communication circuit transmission, steering wheel torque angular signal resolve the steering wheel torque T of module transfer _s, current vehicle speed signal V and steering wheel torque T can be determined according to the basic power-assisted curve of the multiple spot broken line prestored _scorresponding basic Power assisted control electric current I _b;

Consult Fig. 4, in the present invention, basic Power assisted control have employed the basic power-assisted curve of multiple spot broken line.Adopting the advantage of multiple spot broken line to be can the effect of approximating curve type power-assisted curve, realizes simple simultaneously, is convenient to debugging and amendment.The method that the basic power-assisted curve of multiple spot broken line realizes is, vehicle speed signal V is divided into the 1st section: 0Km/h to 10Km/h, the 2nd section: 10Km/h to 20Km/h until the 9th section: 80Km/h to 90Km/h, the 10th section: be greater than 90Km/h.Each section of correspondence steering wheel torque is to the multiple spot broken line of basic power-assisted electric current.Then first each multiple spot broken line should determine 9 unique points, corresponding to 9 unique points on the multiple spot broken line of n-th section be wherein: [T _sn1, I _bn1], [T _sn2, I _bn2] ..., [T _sn8, I _bn8], [T _sn9, I _bn9].The multiple spot broken line then corresponding to n-th section can be expressed as:

$I_b=\left\{\begin{array}{cc}\frac{I_{\mathrm{bn}2}-I_{\mathrm{bn}1}}{T_{\mathrm{sn}2}-T_{\mathrm{sn}1}}(T_s-T_{\mathrm{sn}1})+I_{\mathrm{bn}1}& T_{\mathrm{sn}1}\&le;T_s<T_{\mathrm{sn}2}\\ \frac{I_{\mathrm{bn}3}-I_{\mathrm{bn}2}}{T_{\mathrm{sn}3}-T_{\mathrm{sn}2}}(T_s-T_{\mathrm{sn}2})+I_{\mathrm{bn}2}& T_{\mathrm{sn}2}\&le;T_s<T_{\mathrm{sn}3}\\ \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;\\ \frac{I_{\mathrm{bn}9}-I_{\mathrm{bn}8}}{T_{\mathrm{sn}9}-T_{\mathrm{sn}8}}(T_s-T_{\mathrm{sn}8})+I_{\mathrm{bn}8}& T_{\mathrm{sn}8}\&le;T_s<T_{\mathrm{sn}9}\\ I_{\mathrm{bn}9}& T_{\mathrm{sn}9}\&le;T_s\end{array}\right.---\left(1\right)$

Consult Fig. 3, motor compensating controls submodule and includes friciton compensation control, damping compensation control and inertia compensatory control three part.Friciton compensation controls electric current I _f, damping compensation controls electric current I _d, inertia compensatory control electric current I _i, this three portion of electrical current sum constitutes motor compensating and controls electric current I _c.

Friciton compensation controls to be the Coulomb friction power in order to overcome in motor and speed reduction gearing thereof, and its form is: k _fbe friciton compensation coefficient, θ is motor corner.There is a proportionate relationship between motor rotational angle theta and steering wheel angle θ s, proportionality coefficient can be demarcated in advance.Therefore motor rotational angle theta can calculate according to steering wheel angle θ s.

Damping compensation controls to be the viscosity drag in order to overcome in motor and speed reduction gearing thereof, and its form is: k _dbe damping compensation coefficient, θ is motor corner.

Inertia compensatory control is the force of inertia in order to overcome in motor and speed reduction gearing thereof, and its form is: k _ibe inertia compensating factor, θ is motor corner.

Wherein friciton compensation COEFFICIENT K _f, damping compensation COEFFICIENT K _d, inertia compensating factor K _idemarcated by this area conventional approach.

Consult Fig. 3, initiatively rotary transform tensor submodule comprises back and just judges and return positive current and control two parts.Returning the logic just judged is as steering wheel torque T _sabsolute value be less than a definite value T _sr, and steering wheel angle θ _sabsolute value be greater than a definite value θ _sr, show that bearing circle is in positive state of letting go back, now control Sofe Switch K and be closed into back positive current control.Target direction dish corner is set as 0 °, by bearing circle rotational angle theta _scarry out PID control, obtain back positive current, and to returning the maxim of positive current and minimum value limits under different vehicle velocity V, thus improve bearing circle low speed and return positive deficiency, return at a high speed the phenomenon of positive overshoot.Wherein T _sr, θ _srconcrete numerical value and in different vehicle velocity V, the maxim of positive current, minimum value are rule of thumb set by those skilled in the art next time.Can a preset different vehicle velocity V and return the corresponding table of positive current maxim, minimum value in controller of the present invention, in active rotary transform tensor process can by lookup table mode obtain actual vehicle speed V corresponding return the maxim of positive current and minimum value.

Motor q direction of principal axis target current calculating sub module calculates the axial target current I of motor q according to formula (3) _qref:

I _qref＝I _b+I _c+I _r(3)

Consult Fig. 2, in the present invention, AC induction motor control module have employed the method for vector controlled.Motor three phase current I _a, I _band I _cthrough Clark conversion and Park conversion, be converted to motor d direction of principal axis actual current I _dactual current I axial with q _q.The axial target current I of motor d _drefbe set as 0, with motor d direction of principal axis actual current I _denter d shaft current PID after subtracting each other to control.The axial target current I of the motor q obtained by electric power steering control module _qref, actual current I axial with motor q _qenter q shaft current PID after subtracting each other to control.Control to obtain motor d direction of principal axis target voltage U respectively through d shaft current PID control and q shaft current PID _drefwith motor q direction of principal axis target voltage U _qref, then obtain motor α direction of principal axis target voltage U through Park inverse transformation _{α ref}with motor β direction of principal axis target voltage U _{β ref}.Method finally by Using dSPACE of SVPWM mode and seven segmentations exports the duty cycle signals of each binistor being used for electric machine control.Motor rotor position signal θ (motor corner) has all been used in Park conversion and Park inverse transformation.Wherein the method for Using dSPACE of SVPWM mode and seven segmentations is approach well known.

Clark conversion refers to that static ABC three-phase ordinate transform motor three-phase windings A, B, C formed is static α β two phase coordinate system.α direction of principal axis is right against motor A phase winding direction, and β direction of principal axis is along the direction left-hand revolution 90 ° of winding A phase.Three phase current I _a, I _band I _cbe converted to biphase current I _αand I _βformula be:

$\left[\begin{array}{c}{I}_{\mathrm{\&alpha;}}\\ I_{\mathrm{\&beta;}}\end{array}\right]=\sqrt{\frac{2}{3}}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \frac{\sqrt{3}}{2}& -\frac{\sqrt{3}}{2}\end{array}\right]\left[\begin{array}{c}{I}_A\\ I_B\\ I_C\end{array}\right]$

Park conversion refers to α β two-phase ordinate transform static for motor to be dq two phase coordinate system rotated with rotor.D direction of principal axis is permanent magnet excitation direction, and q direction of principal axis is permanent magnet excitation direction left-hand revolution 90 °, and d direction of principal axis is θ with the angle in the direction of motor A phase.Static biphase current I in patent _αand I _βbe converted to and rotate biphase current I _dand I _qformula be:

$\left[\begin{array}{c}{I}_d\\ I_q\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\&theta;}& \sin \mathrm{\&theta;}\\ -\sin \mathrm{\&theta;}& \cos \mathrm{\&theta;}\end{array}\right]\left[\begin{array}{c}{I}_{\mathrm{\&alpha;}}\\ I_{\mathrm{\&beta;}}\end{array}\right]$

It is α β two phase coordinate system that motor is static that Park inverse transformation refers to the dq two-phase ordinate transform rotated with rotor.The two-phase target voltage U rotated _drefand U _qrefthe two-phase target voltage U of convert to static _{α ref}and U _{β ref}formula be:

$\left[\begin{array}{c}{U}_{\mathrm{\&alpha;ref}}\\ U_{\mathrm{\&beta;ref}}\end{array}\right]=\left[\begin{array}{cc}\cos \mathrm{\&theta;}& -\sin \mathrm{\&theta;}\\ \sin \mathrm{\&theta;}& \cos \mathrm{\&theta;}\end{array}\right]\left[\begin{array}{c}{U}_{\mathrm{dref}}\\ U_{\mathrm{qref}}\end{array}\right].$

Claims (2)

1. the electric boosting steering system control setup based on AC induction motor, it is characterized in that comprising main control chip (1), rotor incremental counter signal acquisition circuit, steering wheel torque angular signal Acquisition Circuit, ACasynchronous motor drive circuit and CAN communication circuit, in described rotor incremental counter signal acquisition circuit, the rotor-position signal of the AC induction motor (6) that rotor-position sensor (10) gathers have passed through RC filter circuit successively and twice negater circuit being made up of Schmidt trigger accesses main control chip (1), in steering wheel torque angular signal Acquisition Circuit, the steering wheel torque angular signal that steering wheel torque rotary angle transmitter (13) gathers have passed through RC filter circuit and operational amplification circuit access main control chip (1) successively, in ACasynchronous motor drive circuit, drive singal after sending from main control chip (1) successively through bus transceiver (2), driving chip (3), high-side switch signal is wherein being boosted by bootstrap circuit after driving chip (3), then three phase full bridge power circuit (5) is accessed, low side switch signal is directly accessing three phase full bridge power circuit (5) after driving chip (3), three phase full bridge power circuit (5) output signal drives AC induction motor to run, the current signal that two current sensors (7) that AC induction motor phase line is installed produce enters main control chip (1) through RC filter circuit and operational amplification circuit, (a CAN communication transceiver (17) between 1, is added in CAN (16) and main control chip.

2., based on an electric booster steering system controller for AC induction motor, it is characterized in that comprising:

Motor rotor position signal resolves module: convert the motor rotor position signal of rotor incremental counter signal acquisition circuit collection to rotor tach signal;

Steering wheel torque angular signal resolves module: export to electric power steering control module after carrying out filtering process to the torque angular signal of steering wheel torque angular signal Acquisition Circuit collection;

Electric power steering control module: comprise basic Power assisted control submodule, motor compensating control submodule, initiatively rotary transform tensor submodule and motor q direction of principal axis target current calculating sub module;

Basic Power assisted control submodule: the current vehicle speed signal V of reception CAN communication circuit transmission, steering wheel torque angular signal resolve the steering wheel torque T of module transfer _s, according to the multiple spot broken line basic power-assisted curve determination current vehicle speed signal V and steering wheel torque T prestored _scorresponding basic Power assisted control electric current I _b; Wherein multiple spot broken line basic power-assisted curve preparation method is as follows:

N section is divided into: V by ascending for the speed of a motor vehicle ₁~ V ₂, V ₂~ V ₃..., V _n-1~ V _n, be greater than V _n; Each section of correspondence steering wheel torque, to basic power-assisted electric current multiple spot broken line, is [T corresponding to the steering wheel torque of n-th section of speed of a motor vehicle to M unique point on basic power-assisted electric current multiple spot broken line _sn1, I _bn1], [T _sn2, I _bn2] ..., [T _sn8, I _bn8], [T _snM, I _bnM], n=1,2 ... N; The steering wheel torque then corresponding to n-th section of speed of a motor vehicle in multiple spot broken line basic power-assisted curve is expressed as basic power-assisted electric current multiple spot broken line:

$I_b=\left\{\begin{array}{cc}\frac{I_{\mathrm{bn}2}-I_{\mathrm{bn}1}}{T_{\mathrm{sn}2}-T_{\mathrm{sn}1}}(T_s-T_{\mathrm{sn}1})+I_{\mathrm{bn}1}& T_{\mathrm{sn}1}\&le;T_s{<T}_{\mathrm{sn}2}\\ \frac{I_{\mathrm{bn}3}-I_{\mathrm{bn}2}}{T_{\mathrm{sn}3}-T_{\mathrm{sn}2}}(T_s-T_{\mathrm{sn}2})+I_{\mathrm{bn}}2& T_{\mathrm{sn}2}\&le;T_s<T_{\mathrm{sn}3}\\ \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;\\ \&CenterDot;& \&CenterDot;\\ \frac{I_{\mathrm{bnM}}-I_{\mathrm{bn}(M-1)}}{T_{\mathrm{snM}}-T_{\mathrm{sn}(M-1)}}(T_s-T_{\mathrm{sn}(M-1)})+I_{\mathrm{bn}(M-1)}& T_{\mathrm{sn}(M-1)}\&le;T_s<T_{\mathrm{snM}}\\ I_{\mathrm{bnM}}& T_{\mathrm{snM}}\&le;T_s\end{array}\right.---\left(1\right)$

Motor compensating controls submodule: calculate motor compensating according to formula (2) and control electric current I _c;

I _c＝I _f+I _d+I _i(2)

Wherein I _ffor friciton compensation controls electric current, k _fit is friciton compensation coefficient; I _dfor damping compensation controls electric current, k _dit is damping compensation coefficient; I _ifor inertia compensatory control electric current k _iit is inertia compensating factor; θ is the motor corner calculated according to steering wheel angle signal θ s;

Initiatively rotary transform tensor submodule: as steering wheel torque T _sabsolute value be less than a definite value T _sr, and steering wheel angle θ _sabsolute value be greater than a definite value θ _srtime enter back positive current control; Target direction dish corner is set as 0 °, by bearing circle rotational angle theta _scarry out PID control, obtain back positive current, and under different vehicle velocity V, the maxim and minimum value of returning positive current are limited thus obtain rotary transform tensor electric current I _r; Wherein in different vehicle velocity V, the maxim of positive current and minimum value obtain by tabling look-up next time; :

Motor q direction of principal axis target current calculating sub module: calculate the axial target current I of motor q according to formula (3) _qref:

I _qref＝I _b+I _c+I _r(3)

AC induction motor control module: converted motor three phase current I by Clark conversion and Park _a, I _band I _cbe converted to motor d direction of principal axis actual current I _dactual current I axial with q _q; By axial for motor d target current I _drefbe set as 0, target current I _drefwith motor d direction of principal axis actual current I _denter d shaft current PID after subtracting each other to control; The axial target current I of the motor q obtained by electric power steering control module _qrefactual current I axial with motor q _qenter q shaft current PID after subtracting each other to control; D shaft current PID control and q shaft current PID control the motor d direction of principal axis target voltage U obtained respectively _drefwith motor q direction of principal axis target voltage U _qrefmotor α direction of principal axis target voltage U is obtained through Park inverse transformation _{α ref}with motor β direction of principal axis target voltage U _{β ref}; Method output motor finally by Using dSPACE of SVPWM and seven segmentations controls each binistor duty cycle signals.