TWI355344B - - Google Patents

Description

1355344 IX. Description of the Invention: [Technical Field] The present invention provides a control method for a vehicle steering system, and more particularly to a return control method using an electric assist steering system. ίPrevious technology】

In the prior art, in order to reduce the burden on the driver to operate the steering system, the liquid (four) system with large output and smooth motion is used as the auxiliary power for the steering secret; but the disadvantage is that the hydraulic pipeline is prone to leakage and the hydraulic oil Friction with the official road is prone to heat generation, and its properties change, and the hydraulic pipeline is more complicated. In recent years, the electric power assisted steering system has been replaced by the electric power steering system (EPS). The EPS system includes servo motor, controller and sensing components. The operation of the Eps system is transferred by the electronic service to complete the steering system. The hydraulic power assisted steering system can be omitted. Which system can omit the hydraulic sump and oil pressure? The pipeline 'and the power used to transmit the engine to drive the pump 2 belt pulley secret' so which system has lower manufacturing cost and maintenance = = EPS system is turned by electronic signal (4), no need = = force ' It can reduce energy consumption; in addition, the coffee system is controlled by the computer program in the auxiliary ===, according to different driving conditions, the required auxiliary power is made, so that the driver's steering action reacts more quickly. The main implementation of the Thousand EPS system is the auxiliary control of the drag, which is the control strategy of the middle. The control strategy is based on the driving direction (4) to estimate the direction of the reaction torque, and the estimated reaction torque is matched with the vehicle speed. To find 5 1355344 to achieve auxiliary gain, multiply this gain by the steering wheel angle and get the control reference signal 'coordinated proportional integral derivative (PID) control rule to control. And know that the EPS system's control strategy is divided into four parts, including basic compensation, damping compensation, inertia compensation and return control; its card, positive control is mainly to estimate the reaction torque acting on the steering column, with basic Subsidy, when the reaction torque gradually becomes smaller, the basic subsidy will give a larger return to the positive help. On the contrary, it will indicate that the system has sufficient self-returning tolerance, so it does not give = assistance; but the disadvantage is that the friction of the steering system The torque belongs to the nonlinear dynamic evil. Therefore, the performance of the PID controller is limited in this part of the performance. When the back-correction assists the multi-torque of 1%, the material is over-steered: the disc cannot be returned to the original center position. The problem needs to be changed. SUMMARY OF THE INVENTION In order to effectively overcome the above-mentioned prior art, the problem of turning the money to cause the direction to return to the near-recording position, the present invention helps the f-direction system to control the method, especially the use-to turn; The pull-type design is based on (4) H' causing the dynamic change of the control, and outputting the positive return under the dynamic (four) / this is based on the performance of the auxiliary steering line. (4) Torque, in order to achieve the above purpose by improving electric power, the present invention provides a method for returning positive control, which includes: a vocational assist steering 、, a charging and a disk=T vehicle speed signal, a driver's wheel torque signal system= Two: the unit calculates the angle signal - the steering system 6 1355344 uses a trigger controller to determine the vehicle state with the vehicle speed signal, the input torque signal and the angle # number, and outputs a trigger signal to a positive controller; Positive control benefit, based on the steering system model, receiving the trigger signal and calculating a dynamic estimation value of the steering system to calculate a positive reference signal of a motor; and using the vehicle speed signal and the input torque signal, A basic auxiliary signal is cross-checked by a basic auxiliary table, and the positive reference signal and the auxiliary signal are summed to obtain an auxiliary torque command of the electric assist steering system to perform the steering control of the steering system. According to this, the dynamic control torque can be output according to the change of the dynamics of the system, so as to achieve the purpose of improving the correctness and stability of the electric assisted steering system. " In addition, the present invention also includes: the trigger controller determines the vehicle mode according to the vehicle speed signal, and when the vehicle speed signal is higher than the preset vehicle speed, the driver's operation state is determined according to the driver input torque signal. The input torque is less than the preset torque, and the direction of the steering wheel angle signal is determined. When the angle is greater than the preset angle, it is determined that the steering wheel is not at the center position, and the position control is determined, and then the state of the positive control is determined, and when the return control is not started The start timer will start timing, and the steering wheel will remain in the above state, so that the start timer is greater than or equal to the preset start time, and the return control will be activated. The steering system model is expressed by an equation: (where: 7 is the moment of inertia of the steering system, $ is the angular acceleration of the steering column, L is the driver's torque acting on the steering column, the motor torque and the road surface 1355344 Torque torque sum, 2> is the friction torque, s is the damping of the steering system, and 6 is the steering column angular velocity). The return control controller is a sliding mode control (SMC), which uses a sliding mode control robust term (r〇bust term) to process the friction torque existing in the steering system and the ambiguous system parameter. , expressed as an equation:

Tre^={Bp~ZIp)eT^~fRW+Ip(ed+Aed)-IpkSat(s,〇) [where: in the formula: for the motor to return positive torque, 'for the damping parameter of the steering system; The positive real number 'this positive real number represents the convergence rate of the variable on the sliding plane, which is the rotational inertia parameter of the steering system, 4 is the steering column angular velocity, 7^„ is the driver input torque, and ^(10) is the estimated reaction torque. For the angular acceleration required to turn the column, 4 is the angular velocity required for the steering column, and k is the strong term 'sat(s, d>) is a continuous saturation function (saturati〇n functi()nM. The sliding mode control has a complex number The system parameters, where the system parameters, and the design parameters & changes, are defined as the following equation: / max (where Δ / is the uncertainty of the moment of inertia of the steering system, its range of variation / min and ^ is a normal number); the variation between the system parameter B and the design parameter' is defined as the following equation: Β = Βρ-Μ (the uncertainty of the damping of the .5 steering system, the range of variation is normal Number); 1355344 The estimated range between the actual reaction forces y ^ is defined as follows Equation;: side reaction

A ^rtss+A^rtss ,|ArRTSS|SQ. Constant) (In the formula, AfRTSS is the range of variation of the estimation accuracy, and the range of variation is "the stability condition of the positive control", which is based on the steering system model.

The sliding plane is required to satisfy the sliding state inequality, and the / indefinite equation is expressed by the following equation: piece = heart - + | (wherein: S is a sliding plane defined by a steering wheel dynamics, the sliding plane by the steering wheel Angle and angular velocity are formed, S is the first-order time derivative of the sliding plane '7 is - positive integer' 4- The Lyapunov ()v equation is the inter-cold cold number, and the Lyapunov equation is slipped The plane 5 is constructed such that the sliding plane satisfies the material equation, the output of the slip-free pure controller is stable, and the state of the sliding state inequality can obtain the k value, so that the k value can be changed according to the τπ dynamic control mode, resulting in the dynamic dynamic energy of the steering wheel. It is controlled within the stable range of 0. The sliding mode controls the k value of the equation, which is obtained by an experiment. When the k value falls within the range of 230 to 550 on the experimental equipment, the controller is overcome by the month b. The uncertainty of the parameters causes the motion dynamics of the steering wheel to be controlled within the set stability range. - The return controller is a phase lead compensation (PLC). 1355344 control design parameters to correct moments to equation:

^return ~ ^net ~ ^RTSS (in the formula: for the motor to return to positive torque, L for torque sum, 4tss for estimated reaction torque). The sum of the torques of the phase lead compensation is obtained by a transfer function according to the error of the steering column angle and the required angle of the steering column, and the main control parameter of the transfer function is a selected phase margin. And the frequency at which the phase is located, and the gain value calculated by the system parameters.

The basic auxiliary table collects the road back positive moment under different vehicle speeds and steering angles, and establishes a basic auxiliary gain two-dimensional look-up table for the small car. However, in order to further clarify the present invention, and to illustrate a preferred embodiment, the detailed description will be described later with reference to the drawings: [Embodiment] Referring to FIG. 1, the back of the electric assist steering system of the present invention is disclosed. The system architecture diagram of the control method illustrates that the vehicle speed signal of the vehicle is captured by a driving computer of the vehicle under test, and the driver 31 is used to measure the rotation of the steering wheel 32 by the driver on the vehicle S. A steering wheel input torque signal 311, and an angle change signal 312 of the steering wheel generated by the driver when the steering wheel 32 is rotated, and the angle signal 312 is calculated by a signal processing unit 21 and an estimation unit 22 to obtain the vehicle. a steering system dynamic estimation value, and using a trigger controller 12 to determine the vehicle state by using the vehicle speed signal, the input torque signal and the angle signal, and outputting a trigger signal to a positive controller 11, the return controller 11 Based on a steering system model, the trigger signal is received and the dynamic estimation value of the steering system is calculated to calculate a 10 1355344 motor 33 The test signal, the torsion signal, to the basic aid table 23 and the 杳 士 = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = In a more specific implementation, the present invention also includes: using the trigger controller 12 to receive the sensor j ', the controller 12 is output after a triggering process: the signal is calculated, the second step is closed, and the controller u' is triggered. The logical operation, according to the speed of the car, is measured by the vehicle, when the trigger control receives the vehicle speed signal higher than the preset speed value 41, then %. _ The driver of the steering wheel inputs the torque signal to determine the driver's operation = state. When the input torque is less than the preset torque value 42, the debt is replaced by the steering wheel angle signal. When the steering wheel angle is greater than the preset angle value 43, the steering wheel is judged. The position control is not required at the center position, and then the state of the controller 11 is determined. When the controller u is not activated 44, the timer 1 is started, and the steering wheel is kept in the above state, so that the timer counts = time. The startup time 45 is greater than or equal to the preset, and the controller 11 will return to the positive control 46. In addition, 'When the positive control 11 has been activated, at which time the driver has not operated the steering wheel' and the steering wheel angle is back to less than the preset value 43, the sensor will detect the steering wheel angle change amount 'trigger controller 12 according to the amount of change Discrimination of the steering wheel state, when the angle change amount is greater than the preset value 47, and after the return control 11 has been activated, the trigger controller 12 determines that the damping compensation control needs to be performed according to the above state, and directly executes Startback control 11 1355344 46, the controller is activated until the steering wheel speed is less than the preset value. - In the second process, the vehicle speed is determined according to the vehicle speed signal. When the trigger speed is received, the vehicle speed signal received by the controller 12 is higher than the preset vehicle speed value 41, and then the sensor detects the steering wheel of the driver and inputs the torque signal to determine the driver. When the steering torque is operated, when the input torque is less than the preset torque value 42, when the steering wheel angle is back to be less than the preset value 43, the sensor detects the steering wheel angle change amount, and the trigger controller 12 determines the steering wheel according to the change amount. The state, when the angle change amount is greater than the preset value 47, at this time, the positive control is not activated 44, and the time that the state continues for 0 is greater than or equal to the preset start time 45 of the timer, and the trigger controller 12 determines according to the above state. If damping compensation control is required, the return controller 46 is activated, and the controller is activated until the steering wheel speed is less than a preset value. • Flow 3 'When the steering wheel angle is back to less than the preset value 43, the sensor will detect the steering wheel angle change amount, and the trigger controller 12 will determine the steering wheel state according to the change amount, when the angle change amount is less than the preset value 47 At this time, the positive control has been started 4, and when the startup state lasts for more than or equal to the closing of the door, the controller 11 is turned off to turn off the positive control 491.

Back to the controller - so that the off timer is timed greater than the return controller 11 will be turned off 12 491. 1355344 to less than the preset angle ί t 'When the steering wheel has been returned to the controller 12 to determine the state of the steering wheel is: to pre: value:: touch! Correction control has started 48, start 舛 neck cry ^ 0g Ning position, When in the above state, the timer is made; and the steering wheel is held 49, the return controller 11 is _end_two f. In a more specific implementation, the present invention also includes: The system model (shown in Figure 1) is expressed by equation (1): (where: / is the moment of inertia of the steering system, her side: column angle (: : Speed = ' ^ is the torque of the driver acting on the steering column, the torque of the motor torque 313 and / the positive torque 315 'the friction torque mb is the damping of the steering system, 6 is the steering column angular velocity. _ The return control system 11 can be a sliding mode control (as shown in FIG. 4), which utilizes the strong term of the sliding mode control, processes the friction torque existing in the steering system and the ambiguous system parameter, and is expressed by equation (7): (A吒)θϋ+他+机)乂(4)(4) Equation (7) * 二卜 is the motor back torsion '' is the damping parameter of the steering system^录二' 5 Haizheng real number represents the variable on the sliding plane Two spare forces, two ugly forces' "For the estimated reaction torque, the steering column is the angular velocity required for the steering column, k is strong") 13 1355344 The sliding mode control system parameters / and the design parameters /p The change is defined as shown in the following equation (3): Ι = ΙΡ ^Ι Equation (3) (where: ΔΖ is the uncertainty of the moment of inertia of the steering system, and the range of variation L and /max is a normal number); the variation between the system parameter β and the design parameter & Equation (4): B = Bp-AB , \AB\</3 Equation (4) (where: the uncertainty of the damping of the A steering system, the range of variation is normal); the actual reaction force The estimated range between the TRTSS and the estimated side reaction force fRTSS is defined as the following equation (5): ^RTSS = ^RTSS + ^^RTSS >|^^RTSs| — a square private (5) ( In the formula: in order to estimate the range of variation of the accuracy, the range of variation is “normal.” The stability condition of the sliding mode control is to define a sliding plane by using the steering system model, and the sliding plane needs to satisfy a sliding state inequality. Wherein the inequality is expressed by the following equation (6): v=5·ί<~7|ί| Equation (6) (wherein: s is a sliding plane defined by a steering wheel dynamics, the sliding plane being the steering wheel angle Consisting of angular velocity, s is the first-order time derivative of a sliding plane, and 7 is a positive The integer 'f is a first-order time derivative of the Lyapunov equation, which consists of the sliding plane s), 14 1355344, "The moving plane satisfies the material equation, which enables the branch to be stable" and can Use the sliding state inequality to take, [2 = set within the stable range] - this is controlled in addition to this, the sliding mode control equation is obtained, the value of k is in the range of 23〇 to 55G' can also be The performance of the system parameters is not fixed, resulting in the steering wheel; the actuator can be set within a stable range. The sorrow month b is controlled at the return controller U can also be a phase

Tnet~TR1, equation (7) (where is the motor's positive torque, and the soldier's measured reaction torque). The total moment of the moment, 4ss is the sum of the moments for estimating the phase lead compensation. The error shift function of the angle of the machine column and the angle required for the steering is based on the main control parameter of the steering, which is the rate of the phase transfer function of the 敎. The basic auxiliary table 23, which is the frequency at which the gain value is calculated from the system parameters, is collected in different vehicle speeds and positive moments, and the basic gamma gain of the small vehicle is established. ” = system dynamic change, and output the dynamic under-return positive work = two to achieve the above-mentioned improved electric auxiliary steering system of the positive and stable 1355344

Matlab/Simulink' was used to simulate the EPS system control strategy with CarSim's vehicle model. There are two main test items, the first one is the steering feel test and the second is the return test' to evaluate the performance of the assist steering strategy. First, the method of turning to the hand test is to apply a fixed frequency (0.2 Hz) sine wave steering angle input to the steering wheel, and the amplitude of the steering angle must be such that the lateral acceleration of the vehicle reaches 〇.2g and is used as a test input. Conditions, test at different speeds, and at the same time, the driver's torque data and the corresponding side • the angle of the disk' is plotted as a phase diagram to analyze the steering feel, and the slope of the curve is observed on the analysis graph. A heavier steering system. Under the speed of 60km / hr, respectively, equipped with Electric P0wer steering (EPS) and EPS-free systems, and draw their respective steering feel phase map, as shown in Figure 5, equipped with Eps system vehicles The slope of the phase diagram is significantly smaller than that of the vehicle without the EPS system. If the driver has a large steering angle, the driver does not need to apply a large torque. Therefore, the steering system with a small slope of the steering phase diagram can be It is summarized as ^ Turning to a system with a lighter feel. In addition, the test data at different speeds is also collected, and the EPS system is analyzed for 6手kni / hr, 7-5knWhr and ^kin/ln·, as shown in the figure, if the vehicle speed is higher, the steering feel is higher. The trend is heavy, and thus, the control strategy ^ meets the actual needs of the car. When the vehicle is in the high-speed driving state, it gives the greener a heavier steering feel, which can improve the resolution of the steering wheel operation, and reduce the driver's steering wheel. Load, improve driving quality and •, and thus improve the safety of high-speed driving. Secondly, returning to the law is to turn the steering wheel, so that the direction 16 1355344 reaches a certain angle and then loosen the steering wheel. The test points are divided into two parts. The first part is the speed of 3〇km / hr, when the driver releases After the steering wheel, the control strategy can detect the triggering strategy and start the return control at the same time, and the steering wheel can be returned to the center position. The second part is the speed of 9〇km / hr. When the driver releases the steering wheel, the steering wheel The response to the correctness is stable, while maintaining a good steering wheel return performance. At a low vehicle speed of 30km / hr, the steering system has the difference of the positive response of the return control and the non-return control, while observing the actuation of the controller output, and drawing the respective steering feel phase diagram, as shown in Figure 7. , the speed of 3 〇 km / hr ^ back to the control of the car auxiliary, where the solid line is the sliding mode control (SHding (2), 1, SMC) method 'the center line for phase lead compensation (test Lead C0mpensation, PLC), phase Compared with the middle dotted line), the steering wheel's returning effect is the frequency of the Bodhisattva vehicle (as shown in Figure 7, and the SMC and PLC method white = back to the center of the vehicle without the positive control) To 9 degrees τ back to positive action, Figure 8 shows that the control self-returning moment is small, so when it is low speed, the steering system t avoids the force about negative one for the force, and the Saki is about two = produced about one The high-speed car speed of 90km / hr under the demon, the sister line in Figure 9 is the non-return control of the H system response as shown in Figure 9, where the vehicle is controlled to produce no earthquake, there is significant oscillation, and It is higher in the vehicle and therefore the steering system itself. As shown in Figure 1G, the control output is shown by The positive return speed is too fast, and the positive return torque is quite large. In order to prevent the steering wheel from being stable, it is given a large damping force. In addition to 17 1355344, the k value of the above SMC can be obtained experimentally. The stable condition under the ff Wei state is less than 1 second, and the steering wheel is back to positive and negative f degrees, which is the stability of the system. Under this condition, the experiment obtains the -k simulation system (4) strategy of the mode t ^ low speed 30km/hl* and high speed 90km/^lr are used to evaluate the performance of the sliding mode controller. As shown in Figure η, 'the speed is 3〇km/hr, 仏23〇 to 5 response As shown in Figure 11, the controller output is in the state of about 9.9 tt. The final response of the system approaches 2 degrees at a k value of 23G, and the k value is 550. Approaching G.6 degrees, the system response falls as shown in Figure 12'. The display of the sliding mode controller output is smaller than the fine positive torque, so the domain direction (four) positive speed 23G' / f dynamic mode control is activated. In an instant, the system is back

Production: 5Nm is to avoid the positive movement more than the center position, so the SMC 〇7 22 2^ damping force' after the system is narrow and the system is stable. After about 7 seconds, the system enters a stable state. Pushing ii^55G's sliding mode control at the moment of starting, the system's back = force is about 'to avoid the positive movement more than the center position, so the shock towel is about 12N-m damping, after which the system continues to shock 〇·2 After the second, the amplitude of the edge is reduced, and the _ system is about 7 seconds later. In the circumference 3 r: back n: 9 ° km / hr under the 'k value 23 〇 to 55. After the second seconds, the system enters the controller and the controller output is about 0.38 -1, the heart is at the k value of 23〇, and the final response of the system approaches ^", the final response of the system approaches 0 degrees, and the system response falls to 18 1355344. The stable range of the design. - As shown in Figure 14, the sliding mode controller output is displayed. At high vehicle speeds, the steering system has a small self-returning torque. Therefore, to speed up the steering wheel, when the k value is 230, the sliding mode is controlled. At the moment of starting, the system's positive thrust is about 4.5Nm, and it oscillates in a narrow range after 1 second. The system enters a steady state after about 48 seconds. · When the k value is 550, the sliding mode is controlled at the moment of starting. The system's positive back thrust is about 1 lN-m, and in order to avoid the positive movement more than the center position, the Xin SMC generates a damping of about 3N-m. After the system continues to vibrate for 2 seconds, the oscillation amplitude is reduced. After about 0.48 seconds, it enters a steady state. It is known from the above verification that when the k value is in the range of 23〇 to 55〇, the 2 SMC can overcome the uncertainty of the system parameters, so that the movement of the steering wheel can be controlled. Within the set stability range. ^This 'PLC and SMC turn at low speed, have good return performance, and have the effect of damping compensation at the same speed, so that the vehicle runs with stability and thus enhances the overall performance and stability of the system. _—Although The invention has been disclosed in the above preferred embodiments. However, it is not intended to limit the scope of the invention, and the scope of the present invention may be modified without departing from the spirit and scope of the invention. The scope defined in the patent application is subject to change. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a system architecture diagram of the present invention. : ^ is the trigger strategy flow chart of the trigger controller of the present invention. 3. The system architecture diagram of the sliding mode controller of the present invention. 19丄乃:)344 Figure 4: System architecture diagram of the phase lead compensation controller of the present invention. Fig. 5 is a comparison diagram of the steering feel phase of the simulated and absent driving state of the present invention. Fig. 6 is a comparison diagram of the steering hand phase of the driving state of the simulated EPS at different vehicle speeds according to the present invention. Fig. 7 is a comparison diagram of the steering angle response of the present invention with and without Eps at a vehicle speed of 3 〇 km / 为本. Fig. 8 is a diagram showing the Eps output torque of the 3 〇km / & Fig. 9 is a comparison diagram of the steering angle response of the present invention with or without Eps under the vehicle speed of 9 〇 km / & Fig. 1 is a diagram showing the output torque of the EPS at a vehicle speed of 90 km/hr. Figure 11 is a comparison diagram of the steering wheel angle response of the simulated SMc with the k value in the range of 23 〇 to 55 , at a vehicle speed of 30 km/hr.

Figure I2 is an output torque diagram of EPS for a simulated k value in the range of 230 to 550 at a vehicle speed of 30 km/hr. Figure 13 is a comparison diagram of the steering wheel angle response of the simulated SMc with the k value of the simulated SMc in the range of 55 〇 and the vehicle speed of 90 km/hi. Figure 14 is a diagram showing the output torque of the EPS of the simulated SMC with the k value in the range of 230 to 550 and the vehicle speed of 90 km/hr. [Main component symbol description] 11 Positive controller Trigger controller 20 12

Claims (1)

1355344 X. Patent application scope: 1. An electric_assisted steering system's return control method includes: and sense! 1 measuring a vehicle speed signal, a driver input torque signal and a steering wheel angle signal; The second angle unit calculates the angle signal 'to obtain the steering system using the - trigger (four) device to determine the vehicle state by using the vehicle speed signal and the input twist signal, and outputting a trigger signal to the second positive control unit. The system is a sliding mode control, and based on the - steering system model, the sliding mode control is used to control the friction torque and the ambiguous system parameters in the steering system. The following financial formula indicates: Tre^ m ={Βρ~λΙρ)θ- - fRTSS + /pfeat (5> φ) (where: L is the motor back torsion, & is the damping parameter of the steering system > 1 is the positive real number 'The positive real number represents Wei The convergence rate on the sliding plane, \ is the moment of inertia parameter of the steering system, 彡 is the angular velocity of the steering column, 『 input the torque for the driver'. For the estimated reaction torque, the color is the rotation: machine: the required angular acceleration'_ to the required angular velocity of the column, k is strong as a continuous saturation function); ' ^ The positive controller receives the trigger signal and calculates the dynamic estimation value of the steering system to calculate a positive return reference signal of a motor; And using the vehicle speed signal and the wheel torque signal, cross-checking with a basic auxiliary table - basic_minus, summing the reference signal and the auxiliary signal to obtain an auxiliary torque command of the electric assist steering system to perform steering 2. The method of returning positive control of the electric auxiliary steering system according to claim 1, wherein the trigger controller determines the vehicle mode according to the vehicle speed signal when the vehicle speed signal is higher than The preset speed is determined according to the driver's input torque signal, and the driver's operating state is determined. When the wheel torque is less than the preset torque, the steering wheel angle signal is continuously determined. When the angle is greater than the preset angle, the steering wheel is not centered. The position needs to be controlled by position, and then the status of the positive control is determined. When the control is not started, the start timer will start. Timing, and the steering wheel is kept in the above state, so that the start timer is greater than or equal to the preset start time, and the return control is activated. 3. The return control method of the electric assist steering system according to the first application of the patent scope , wherein the steering system molding is expressed by the following equation: (where: / is the moment of inertia of the steering system, 4 is the angular acceleration of the steering column, "the driver's torque on the steering column, the motor torque and the road returning moment The twisting force is the friction torque, 5 is the damping of the steering system, and ^ is the steering column angular speed. The motor-assisted steering system Urni: 2^, which is the patent range, the sliding mode control With the plural system parameters, the change between the ~number and the design parameter /p is defined as the following equation ^ 'A: (where ΔΖ is the uncertainty of the moment of inertia of the steering system, and I is the normal number); the range of variation between the variation system parameter 5 and the design parameter 'is defined as | 23 Equation: Β = Βρ -ΑΒ ,|Δ5|<;5 Uncertainty of damping, the range of variation Θ is (the normal number of the steering system); the estimation of the range of the reaction force (five) ^RTSS = ^RTSS + A^RTSS »|ΔΓκτ88| g α (where: △) constant) is the variation range of the estimation accuracy, and the variation range is positive 5·如申#专利|&围围The stability condition of the 4 sliding mode control in the positive control method of the electric auxiliary steering system is to use the steering system-type sliding-sliding plane, the sliding plane needs to satisfy the sliding state inequality, and the inequality is The following financial program indicates: V = ^i <-^|^| ^ The sliding plane of the mosquito to the disk dynamics, which is composed of the sliding plane and the angular velocity, ^ is a first-order second-order time of a sliding plane ^ a Lyapunov-V) equation; I Lyapunov equation 甴 sliding plane 5 The configuration enables the sliding mode controller to be stable when the sliding plane satisfies the inequality. 6. If the patent control method is applied to the control method, the sliding control module 5 of the electric auxiliary steering system is returned to the formal control equation, and the sliding 24 1355344 inequality is used to obtain 'k value according to the lining (4) The 彳 mode changes, causing the steering wheel to be controlled within the set stability range. 7. The method of returning positive control of the electric assist steering system according to item 1 of the patent scope, wherein the sliding mode control equation k value is obtained by an experiment, when the k value falls within the range of 230 to 55 ,, The controller can overcome the uncertainty of the system parameters, so that the motion dynamics of the steering wheel can be controlled within the set stable range. • 8. The method of return control of the electric assist steering system according to the scope of claim 1 of the patent application, wherein the basic auxiliary table, you collect the road returning moment under different vehicle speeds and steering angles, and establish the basic auxiliary of the small pear car Gain two-dimensional 杳 • table. - 9. A bait positive control method for a motor-assisted steering system, comprising: a sensor for measuring a vehicle speed signal, a driver input torque signal and an angle signal of a steering wheel; - operating via a signal processing unit The chirp signal is used to obtain a dynamic estimation value of the steering system; ', using a trigger controller to use the vehicle speed signal, the input torque signal and the angle to break the handle state, and rotate a trigger signal to one time. The positive controller; s positive controller is a phase lead compensation, and based on the steering system module 1, the adjustment design parameters are used to correct the control torque, expressed in the following formula: (Formula i Ψ , ^e /wrri is the positive torque of the motor ^ is the sum of the moments, which is the estimated reaction torque of 25-measurement; Λ °hai back to the controller receives the trigger signal and calculates the dynamic estimation value of the steering system to calculate a motor A reference signal is used once; and the vehicle speed signal and the input torque signal are used to check and obtain a basic auxiliary signal 'the positive reference signal and the auxiliary signal The total 'get the assist torque command power-assisted steering system, the steering system to perform the back to the positive control. 1〇. The method of returning positive control of the electric auxiliary steering system according to claim 9 of the patent scope, wherein the sum of the torques of the phase lead compensation is determined by a transfer f number according to the angle of the steering column and the required angle of the steering column The error is obtained. The main control parameter of the transfer function is a selected phase margin and the frequency at which the phase is located, and the gain value calculated by the system parameter is used to determine the steering wheel angle signal. When the angle is greater than The preset angle, = direction, position control is not required at the center position, and then discriminates back to 'When the positive control is not started, the start timer will start the dial angle signal. 11. The method of returning positive control f of the electric assist steering system according to claim 9 of the patent application, wherein the trigger controller determines the vehicle mode according to the vehicle speed signal. When the vehicle speed signal is higher than the preset vehicle speed, then according to (4) The input torque signal 'discriminate the driver's operation state, when the input torque is less than the preset twist (in the formula: / is the rotation inertia of the rotation (four) system," is the steering column angular acceleration 'used on the steering touch Torque, horse hybrid Weimail positive torque twist W 7 > for the friction torque '5 for the steering system damping, 6 for the steering degree). Zheng 13. The return control method of the electric auxiliary steering system according to claim 9 of the patent application scope, wherein the basic auxiliary table is collected at different vehicle speeds and steerings: performing road surface returning moment, and establishing a basic auxiliary gain of the small car Dimensional table. A method for controlling the return control of a motor-assisted steering system, comprising: measuring a vehicle speed signal, a driver wheel torque signal and an angle signal of a steering wheel by using a sensor; and calculating the angle signal via a signal processing unit, To obtain the dynamic estimation value of the steering system; ^ use a trigger controller to determine the vehicle state by using the vehicle speed signal, the input torque signal and the angle k, and output a trigger signal to a positive controller; The controller is configured to receive the trigger signal and calculate a dynamic estimated value of the steering system to calculate a positive reference signal of a motor; and use the vehicle speed signal and the input torque signal, A basic auxiliary signal is detected and a basic auxiliary signal is detected, and the positive reference signal and the auxiliary signal are summed to obtain an auxiliary torque command of the electric assist steering system to perform the steering back control. 15. The method of returning positive control of the electric assist steering system according to claim 14, wherein the trigger controller determines the vehicle mode 1355344 according to the vehicle speed signal when the vehicle speed signal is higher than a preset vehicle speed, and then according to driving The input torque signal is used to determine the driving state of the driver, and when the input torque is less than the preset torque, the steering wheel angle signal is successively determined. When the angle is greater than the preset angle, it is determined that the steering wheel is not at the center position, and position control is required, and then the determination is made. When the control of the positive control is not started, the start timer will start counting, and the steering wheel will remain in the above state, so that the start timer is greater than or equal to the preset start time, and the return control will be started. 16. The method of returning positive control of a motor-assisted steering system according to claim 14 wherein the steering system model is expressed by the following equation: ~Tsum - βθ (where: / is the moment of inertia of the steering system, 4 Augmenting the angle of the steering column is the force of the tester acting on the steering column, the torque of the motor and the torque of the positive torque of the road ~, & 7} is the friction torque, 5 is the damping of the steering system, and 6 is the steering Column angular velocity). 17. The method for controlling the back-to-back control of the electric assisted steering system according to claim 14 of the patent application, wherein the return controller is a sliding mode control, and the robust item processing using the sliding mode control exists in the steering system The friction torque and the ambiguous system parameters are expressed by the following equation: retum λΐρ^θ~~TRTSS +1p{〇d + λθά^-Ipksat(ί, (in the case of the motor back to the positive torque, meaning the steering system The positive parameter of the damping parameter, the convergence rate of the red real number on the sliding surface, the rate of inertia is the angular velocity of the steering column, and I 28 1355344 is the input torque of the driver. Atss is estimated. The reaction torque, which is the angular acceleration required for the steering column, is the required angular velocity of the steering column, 'k is a strong term, and sat(s, (D) is a continuous saturation function). The method for controlling the return control of the electric assist steering system, wherein the sliding mode controls the stray complex system parameter, wherein the change between the system parameter/the design parameter , is defined by the following equation ( Medium: ΔΖ is the uncertainty of the moment of inertia of the steering system, and its range is; W is the normal number); the variation between the system parameter 5 and the design parameter A is defined as follows: Β = Βρ-ΑΒ , \^Β\<β (in the middle of the steering system, the weight of the damping is not normal, the normal number of changes); Α is the actual reaction between rRTSS and the reaction force of the estimated side is too wide, defined as The following equation is shown: ^RTSS = -^RTSS + ^^RTSS >|^^RTSs| ^ CC constant) (In the formula, ArRTSS is the range of variation of the estimated accuracy, and the range of variation is "for the foot 19. The motor-assisted steering system referred to in Item 17 of the patent dry circumference is controlling the condition of the (4) motion mode (4) of the towel, and the side-oriented system-like-sliding plane, the sliding plane 29 inequality, wherein the inequality is based on the following equation Representation: V. (= where .5 is the sliding plane defined by the steering wheel dynamics, which is composed of ^ steering wheel angle and angular velocity," is the first-order 彳曰 derivative of the sliding plane, 77 is a positive integer. f is a Lyapunov equation =). The step-time derivative, which is constructed by the sliding plane s, and the sliding plane satisfies the material, which enables the sliding controller to lose 20. As claimed in the patent scope, the 19th rhyme electric lion steering system The method of returning to the 7th method, wherein the sliding mode control equation k value is obtained by using the slip state inequality, so that W can be changed according to the sliding control mode, and the motion of the steering disk can be controlled within the set stable range. 21. The method according to claim 17, wherein the sliding mode control equation is controlled by a 2, and when the planting falls into the range of 23〇 to 55〇, The controller can overcome the inaccuracy of the number of 'systems' so that the motion dynamics of the steering wheel can be controlled within a set stable range. 22. The method of returning positive control of the electric auxiliary steering system according to claim 14 of the patent application scope is as follows: the phase advance compensation controller is used to adjust the control parameters to correct the control torque, and is expressed by the following silk formula. : Tretum _ Tnet -fRTSS 30 (where: for the motor to return positive torque, L for torque total, 4tss for estimated reaction torque). 23. The method of returning positive control of the electric assist steering system according to claim 22, wherein the sum of the torques of the phase lead compensation is determined by a transfer function according to the angle between the steering column angle and the required angle of the steering column. It is found that the main control parameter of the transfer function is a selected phase margin and the frequency at which the phase is located, and the gain value calculated by the system parameters. 24. The method of returning positive control of the electric assisted steering system according to claim 14 of the patent application, wherein the basic auxiliary table collects the road returning moment under different vehicle speeds and steering angles, and the basic auxiliary gain of the small vehicle is established. Check table. 31