Electric power steering starting viscosity compensation control device and method

Abstract

The invention discloses an electric steering starting viscosity compensation control device and method, and the device comprises a torque sensor, a torque controller, and a detection unit which is used for detecting a rotating speed signal and a rotating angle signal of a motor or a steering wheel, and removing noise; the viscous state detection unit is used for calculating a viscous state quantity according to the read-in noise-removed motor rotating speed signal and the noise-removed motor angle signal provided by the detection unit and a preset rule; a state activation control means for reading the de-noised rotational speed signal output by the position detection means, the torque signal output by the torque sensor, and the viscous state quantity output by the viscous state detection means, and calculating an activated state quantity; and the high-frequency wave transmitter transmits a high-frequency wave current signal according to the activation state quantity output by the state activation control unit. According to the invention, the motor is controlled to output high-frequency oscillation components, so that the viscous phenomenon at the starting moment of the electric steering device is effectively eliminated.

Description

Technical Field

[0001] The invention relates to the field of motor vehicle control, and in particular to an electric steering startup viscosity compensation control device and method. Background Art

[0002] With the development of the automotive industry, the performance requirements in various aspects such as driving experience are getting higher and higher, and drivers have also put forward higher requirements for the steering performance of the car. As one of the most easily perceived problems by end users, starting viscosity has caused more and more user complaints in recent years. How to effectively reduce the related problems caused by mechanical viscosity during the steering start process has become a research focus of general concern for technical developers.

[0003] After the vehicle has been driving in a straight line for a long time at high speed, the driver operates the steering wheel to steer. At the moment the steering wheel starts to turn from stationary, the driver will feel stickiness, and the steering force will return to normal after turning.

[0004] At different vehicle speeds, the starting viscous torque varies. The higher the vehicle speed, the greater the starting viscous torque, and the greater the impact on the driver's driving steering behavior. When the starting viscous torque is small, the driver can feel the stickiness and unevenness of the starting process. When the starting viscous torque is large, the driver needs to overcome the large viscous torque to achieve steering. After the steering wheel is turned, the viscous torque disappears. Due to inertia, the driver maintains a large hand torque to turn the steering wheel, causing the steering wheel to shake at a large angle, seriously affecting the vehicle's operational stability and safety at high speeds.

[0005] Usually, the cause of the starting sticking phenomenon is poor lubrication of the worm gear, out-of-tolerance worm gear size, sharp edges on the worm top teeth, etc., which cause poor meshing of the worm gear and excessive maximum static friction or friction coefficient, thus causing the starting sticking phenomenon. At present, some solutions are to improve the manufacturing process of the worm gear to ensure the consistency of product processing, and at the same time fully inject lubricating grease, or adjust the viscosity of the lubricating grease to avoid poor meshing of the worm gear as much as possible. However, this method is not accurate enough and cannot accurately adjust the sticking phenomenon. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a device and a method, which can identify the start-up sticking with high accuracy and simply eliminate the start-up sticking phenomenon through a control method.

[0007] In order to solve the above technical problems, the present invention provides an electric power steering start-up viscosity compensation control device, comprising:

[0008] Torque sensor, which detects the driver's steering torque;

[0009] A torque controller reads the steering torque detected by the torque sensor and calculates and obtains the auxiliary torque current;

[0010] A detection unit, used to detect the rotational speed signal and the rotational angle signal of the motor or the steering wheel, and remove noise;

[0011] A viscous state detection unit, which reads the noise-removed motor rotational speed signal and angle signal provided by the detection unit, and calculates the viscous state quantity according to a preset rule;

[0012] A state activation control unit reads the noise-removed rotational speed signal output by the position detection unit, the torque signal output by the torque sensor, and the viscous state quantity output by the viscous state detection unit, and calculates the activation state quantity;

[0013] A high-frequency wave transmitter emits a high-frequency wave current signal according to the activation state quantity output by the state activation control unit;

[0014] An adder is used to add the auxiliary torque current output by the torque controller to the high-frequency wave current output by the control high-frequency wave transmitter to obtain the target current for controlling the motor.

[0015] Preferably, it further includes,

[0016] A current detection unit, which detects the current of the motor drive circuit;

[0017] A current control unit performs consistent control processing on the target current and the current detected by the current detection unit, forms a drive current and outputs it to the motor, and generates an assist torque for assisting the steering force provided by the driver to the steering shaft.

[0018] Preferably, the preset rule in the viscous state detection unit is that when the read rotational speed signal is greater than the threshold value, it is considered that the system does not have viscosity; when the read rotational speed signal is less than the threshold value, and the holding time is greater than the preset value, and the angle slip amount is less than the threshold value, it is considered that the system has viscosity.

[0019] Preferably, the state activation detection unit determines whether to activate the high-frequency wave transmitter by calculating the expected rotational speed according to the steering torque signal read from the torque sensor and the current signal read from the current detection unit, and comparing it with the rotational speed signal read from the detection unit.

[0020] Preferably, when the expected rotational speed is greater than the rotational speed signal, the high-frequency wave transmitter is activated.

[0021] Preferably, the expected rotational speed is calculated according to the following method:

[0022] The torque gradient is calculated based on the signal of the steering torque read from the torque sensor, and then the first expected speed is calculated based on the torque gradient. The motor output torque is calculated based on the motor current signal read from the current detection unit, and then the second expected speed is calculated based on the motor output torque. The smaller value of the first expected speed and the second expected speed is taken as the expected speed.

[0023] Preferably, it further includes a motor, and the detection unit is a position detection unit for detecting the rotational speed signal and the rotation angle signal of the motor.

[0024] Preferably, the torque sensor is a torsion angle sensor, and the detection unit is arranged in the torsion angle sensor.

[0025] The present invention also discloses an electric steering start-up stickiness compensation control method, including the following steps:

[0026] Step 1: Monitor and read the steering torque value, the rotation angle and the rotational speed value of the steering wheel of the driver.

[0027] Step 2: Read the steering torque value, the rotation angle and the rotational speed value in Step 1, and respectively calculate the auxiliary torque current and the stickiness state quantity.

[0028] Step 3: Read the steering torque value, the rotational speed value of the steering wheel and the stickiness state quantity to calculate and obtain the activation state quantity.

[0029] Step 4: Read the activation state quantity to calculate and obtain the high-frequency wave current.

[0030] Step 5: Add the high-frequency wave current to the auxiliary torque current to calculate and obtain the target current.

[0031] Step 6: Output the target current and the drive current corresponding to the PWM signal to the motor, and the motor generates an auxiliary torque to assist the steering force provided by the driver to the steering shaft.

[0032] Preferably, in Step 2, the calculation method adopts a method of calculating based on predetermined mapping data.

[0033] Compared with the prior art, the present invention can accurately detect the steering torque of the driver, the rotation angle of the motor and the rotational angular velocity of the motor, and effectively eliminate the stickiness phenomenon at the moment of starting of the electric steering device by controlling the high-frequency oscillation component output by the motor. Description of the Drawings

[0034] The accompanying drawings of the present invention are intended to show the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the present invention, and to supplement the descriptions in the specification. However, the accompanying drawings of the present invention are schematic diagrams not drawn to scale, and may not be able to accurately reflect the precise structures or performance characteristics of any given embodiment. The accompanying drawings of the present invention should not be construed as limiting or restricting the scope of the numerical values or properties covered by the exemplary embodiments of the present invention. The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0035] Figure 1 It is a block diagram showing the structure of the electric power steering control device according to Embodiment 1 of the present invention.

[0036] Figure 2 It is a flowchart showing the processing inside the microprocessor in Embodiment 1 of the present invention.

[0037] Figure 3 It is a block diagram showing a structural example of the viscous state detection unit according to Embodiments 1 and 2 of the present invention.

[0038] Figure 4 It is a predetermined mapping data table 1 of the state activation control unit according to Embodiments 1 and 2 of the present invention.

[0039] Figure 5 It is a predetermined mapping data table 2 of the state activation control unit according to Embodiments 1 and 2 of the present invention.

[0040] Figure 6 It is an output waveform showing an operation example of the high-frequency wave transmitter in Embodiment 1 of the present invention.

[0041] Figure 7 It is a block diagram showing the structure of the electric power steering control device according to Embodiment 2 of the present invention.

[0042] Figure 8 It is a flowchart showing the processing inside the microprocessor in Embodiment 2 of the present invention.

[0043] Figure 9 It is an output waveform showing an operation example of the high-frequency wave transmitter in Embodiment 2 of the present invention. Detailed Description of the Invention

[0044] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited only to the specific embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary specific embodiments to those skilled in the art.

[0045] Embodiment 1:

[0046] Figure 1 FIG. is a block diagram showing the structure of the electric power steering control device according to Embodiment 1 of the present invention. Details of the electric steering device itself are omitted here and may be a well-known structure.

[0047] An electric steering start-up viscous compensation control device, characterized by comprising:

[0048] A torque sensor for detecting the steering torque of the driver;

[0049] A torque controller for reading the steering torque detected by the torque sensor and calculating to obtain an auxiliary torque current;

[0050] A detection unit for detecting the rotational speed signal and the rotation angle signal of the motor or the steering wheel and removing noise;

[0051] A viscous state detection unit for calculating a viscous state quantity according to the noise-removed motor rotational speed signal and angle signal provided by the detection unit read in and according to a preset rule;

[0052] A state activation control unit for reading the noise-removed rotational speed signal output by the position detection unit, the torque signal output by the torque sensor, and the viscous state quantity output by the viscous state detection unit to calculate an activation state quantity;

[0053] A high-frequency wave transmitter for transmitting a high-frequency wave current signal according to the activation state quantity output by the state activation control unit;

[0054] An adder for adding the auxiliary torque current output by the torque controller and the high-frequency wave current output by controlling the high-frequency wave transmitter to obtain a target current for controlling the motor.

[0055] Specifically, in Figure 1In this case, the steering torque τ0 of the driver is detected by a torque sensor 1 using a well-known torsion bar or the like, and based on the output of the torque sensor, an auxiliary torque current I is provided to the motor 5 by an operation torque controller 2. a The current of the motor drive circuit 4 is detected by a well-known current detection unit 6, and the output torque of the motor 5 is calculated based on the current signal Id from the current detection unit 6. On the other hand, in this embodiment, the detection unit is a position detection unit 7, and the rotation angle and rotation speed of the motor 5 are detected by a well-known position detection unit, and the rotation speed signal Sn from the position detection unit 7 is filtered to remove the noise component from the rotation speed signal Sn and only retain the steering component.

[0056] Based on the noise-removed motor rotation speed signal Sn and angle signal Sm provided by the position detection unit 7, a viscous state quantity Sa is calculated by a viscous state detection unit 8; based on the noise-removed rotation speed signal Sn provided by the position detection unit 7, the torque signal τ0 output by the torque sensor 1, and the viscous state quantity Sa calculated by the viscous state detection unit 8, an activation state quantity Sb is calculated by a state activation control unit 9; the activation state quantity Sb calculated by the state activation control unit 9 controls a high-frequency wave transmitter 10 to transmit a high-frequency wave current signal Is, and the high-frequency wave current Is is added to the auxiliary torque current Ia from the torque controller 2 by an adder 11 to obtain a target current It for controlling the motor 5. The current control unit 3 performs control to make the calculated target current It consistent with the current Id detected by the current detection unit 6, and outputs it as a voltage command signal Sv such as a PWM signal to a drive circuit 4 composed of an H-bridge circuit, for example, and thereby outputs a drive current corresponding to the PWM signal to the motor 5. The motor 5 generates an assist torque to assist the steering force provided by the driver to the steering shaft.

[0057] In Figure 1 the structural blocks of the control device shown are not all composed of hardware, and the structure from the output torque signal τ0 of the torque sensor 1 to the calculation of the target current It by the adder 11 based on the rotation speed signal Sn detected by the position detection unit 7, or the structure until the voltage command signal Sv from the current control unit 3, is composed of software implemented by a microprocessor. The microprocessor includes a well-known central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and interface (IF), etc., sequentially extracts the programs stored in the ROM and performs desired calculations through the CPU and temporarily stores the calculation results in the RAM, etc., so as to execute the software and perform a specified control action.

[0058] Based on Figure 2Flowchart for explaining the operation of the electric power steering startup viscous compensation control device with the above structure. First, in step S101, the steering torque signal τ0, which is the output of the torque sensor 1, is read into the microprocessor and stored in the memory. Next, in step S102, the angle signal Sm and the rotational speed signal Sn read from the position detection unit 7 are stored in the memory. Next, in step S103, for the steering torque signal τ0, the auxiliary torque current Ia is calculated by the torque controller 2, and its output is stored in the memory. Here, the torque controller 2 can also be a known method, for example, a method of calculation based on predetermined mapping data. In step S104, for the angle signal Sm and the rotational speed signal Sn read from the position detection unit 7, the viscous state quantity Sa is calculated by the viscous state detection unit 8, and its output is stored in the memory. In step S105, the steering torque signal τ0 read from the torque sensor 1, the rotational speed signal Sn read from the position detection unit 7, and the viscous state quantity Sa calculated by the viscous state detection unit read from the memory are used to calculate the state activation quantity Sb by the state activation control unit, and its output is stored in the memory.

[0059] In step S106, for the state activation quantity signal Sb read from the memory, the high-frequency wave current signal Is is calculated by the high-frequency wave transmitter 10 and stored in the memory. Then, in step S107, in the adder 11, the high-frequency wave current signal Is is added to the auxiliary torque current Ia from the above torque controller 2 to determine the target current It. The operation of determining the target current It is repeated for each control sampling from the above steps S101 to S107.

[0060] Next, the viscous state detection unit 8 is explained: The viscous state quantity Sa is calculated based on the angle signal Sm and the rotational speed signal Sn read from the position detection unit 7. The viscous state quantity Sa is used to determine whether the steering system actually experiences viscous. If the system does not experience viscous, the system will not activate the emission of the high-frequency wave current signal Is. When the read rotational speed signal Sn is greater than the threshold Sn1, it is considered that the system does not experience viscous, and at this time, the viscous state quantity Sa = 0; when the read rotational speed signal Sn is less than the threshold Sn2 and the holding time is greater than T, and the angular slip amount Am is less than the threshold Am1, it is considered that the system experiences viscous, and at this time, the viscous state quantity Sa = 1;

[0061] Figure 3It is a block diagram showing a general structural example of the viscous state detection unit 8, including: determining the state condition 1 of whether the angular slip amount Am of the start timing and the end timing calculated according to the angular signal Sm output by the above-mentioned position detection unit 7 is less than the threshold value Am1; determining the state condition 2 of whether the rotational speed is less than the threshold value Sn2 according to the rotational speed signal Sn output by the above-mentioned position detection unit 7; the viscous state detection unit 8 should include a timer inside. If the determination of the state condition 2 is satisfied, the timing starts. When the timing time is greater than T and the determination of the state condition 2 is satisfied, the viscous state determination condition is satisfied, and it is considered that the system enters the viscous state. At this time, the viscous state quantity Sa = 1. If the determination of the state condition 1 or the state condition 2 is not satisfied, it is considered that the system exits the viscous state. At this time, the viscous state quantity Sa = 0. According to Figure 3 the method, the viscous state detection unit 8 can be simply constituted by general elements.

[0062] Next, the state activation detection unit 9 will be described: The state activation quantity Sb is calculated according to the steering torque signal τ0 read from the torque sensor 1, the rotational speed signal Sn read from the position detection unit 7, and the viscous state quantity signal Sa read from the memory. The state activation quantity Sb is used to activate the high-frequency wave transmitter 10. If it is not activated, the high-frequency wave current signal Is will not be emitted. The viscous state quantity signal Sa reflects whether the mechanical components such as the worm and worm gear part have actually become viscous. Only when the mechanical components actually become viscous is it necessary to activate the high-frequency wave transmitter 10. In addition, some conditions are required to activate the high-frequency wave transmitter 10: The expected rotational speed Sr is calculated by according to the steering torque signal τ0 read from the torque sensor 1 and the current signal Id read from the current detection unit 6, and compared with the rotational speed signal Sn read from the position detection unit 7, so as to determine whether to activate the high-frequency wave transmitter 10.

[0063] The high-frequency wave transmitter can be activated by the following method:

[0064]

[0065] The expected rotational speed Sr is the key condition for the system to determine whether to activate the high-frequency wave transmitter 10. The torque gradient G is calculated according to the steering torque signal τ0 read from the torque sensor 1 τ , where the torque gradient G is calculated τ It can be a well-known method, such as the differential method. Then, according to the torque gradient G τCalculate the first expected rotational speed Sr1, where calculating the first expected rotational speed Sr1 can be a well-known method, such as a method of calculation based on predetermined mapping data. Calculate the motor output torque τ1 according to the motor current signal Id read from the current detection unit 6, where calculating the motor output torque τ1 can be a well-known method, such as a method of estimating the output torque of a permanent magnet synchronous motor based on sampled current. Then calculate the second expected rotational speed Sr2 according to the motor output torque τ1, where calculating the second expected rotational speed Sr2 can be a well-known method, such as a method of calculation based on predetermined mapping data. Take the smaller value of the first expected rotational speed Sr1 and the second expected rotational speed Sr2 as the expected rotational speed Sr.

[0066] The expected rotational speed Sr can be calculated by the following method:

[0067] Torque gradient G τ = Gradient operator Grad(signal τ0 of the steering torque)

[0068] The first expected rotational speed signal Sr1 = Mapping data table 1(torque gradient G τ )

[0069] The motor output torque τ1 = Motor torque estimation operator(current signal Id)

[0070] The second expected rotational speed signal Sr2 = Mapping data table 2(motor output torque τ1)

[0071] IF(the first expected rotational speed signal Sr1 > the second expected rotational speed signal Sr2)

[0072] The expected rotational speed signal Sr = The second expected rotational speed signal Sr2

[0073] ELSE

[0074] The expected rotational speed signal Sr = The first expected rotational speed signal Sr1

[0075] ENDIF

[0076] Next, the mapping data table 1 of the first expected rotational speed Sr1 will be described.

[0077] Calculate the torque gradient G according to the signal τ0 of the steering torque read from the torque sensor 1 τ , and then calculate the first expected rotational speed Sr1 according to the torque gradient G τ . Calculate the first expected rotational speed Sr1 according to the torque gradient G τ as shown in Figure 4 : The first expected rotational speed Sr1 is positively correlated with the torque gradient G τ , and calculate the first expected rotational speed Sr1 by judging the change characteristics of the steering torque gradient G τ during the starting phase. In the steering torque gradient Gτ When it is small, the first desired rotational speed Sr1 increases with the steering torque gradient G τ increasing, and a larger steering torque gradient G τ does not calculate a larger first desired rotational speed Sr1.

[0078] Next, the mapping data table 2 of the second desired rotational speed Sr2 will be described.

[0079] The motor output torque τ1 is calculated based on the motor current signal Id read from the current detection unit 6, and then the second desired rotational speed Sr2 is calculated based on the motor output torque τ1. Calculating the second desired rotational speed Sr2 based on the motor output torque τ1 is as Figure 5 shown: The second desired rotational speed Sr2 is positively correlated with the motor output torque τ1, and the second desired rotational speed Sr2 is calculated by judging the change characteristics of the motor output torque τ1 during the starting stage. When the motor output torque τ1 is small, the slope of the second desired rotational speed Sr1 increasing with the motor output torque τ1 is larger.

[0080] Next, the high-frequency wave transmitter 10 will be described: The high-frequency wave transmitter 10 is used to transmit high-frequency oscillation waves, which can be in the form of periodic sine waves, square waves, or triangular waves, etc., and the frequency is in the range of 50 Hz - 120 Hz. The activation or deactivation of the high-frequency wave transmitter 10 to transmit high-frequency oscillation waves is controlled by the activation state quantity Sb. As Figure 6 shown, taking a square wave with a frequency of 50 Hz and a duty cycle of 50% as an example, when the high-frequency wave transmitter 10 is activated, it starts to transmit a high-frequency oscillation square wave, and stops transmitting when it is deactivated. To ensure the smoothness of the steering start process, the amplitude of the square wave transmitted will be gradually increased or decreased during the start and stop transmission processes. Figure 6 The amplitude of the square wave in [[ ]] is only for illustration and does not represent the actual magnitude of the high-frequency wave current transmitted.

[0081] Embodiment 2

[0082] Figure 7 is a block diagram showing the structure of the electric power steering control device according to Embodiment 2 of the present invention. The detailed description of the electric steering device itself is omitted here, and it can be a well-known structure.

[0083] In [[ ]] Figure 7 the steering torque τ0 of the driver is detected by using a well-known torsion angle sensor 1, and the auxiliary torque current I provided to the motor 5 by the torque controller 2 is calculated based on the output of the torsion angle sensor ɑ。The current of the motor drive circuit 4 is detected by a known current detection unit 6, and the output torque of the motor 5 is calculated based on the current signal Id from the current detection unit 6. On the other hand, the rotation angle Sm and rotation speed Sn of the steering wheel are detected by a known torsion angle sensor 1, and the rotation speed signal Sn from the torsion angle sensor 1 is filtered to remove the noise component from the rotation speed signal Sn, leaving only the steering component.

[0084] Based on the noise-removed motor rotation speed signal Sn and angle signal Sm provided by the torsion angle sensor, the viscous state quantity Sa is calculated by the viscous state detection unit 8; based on the noise-removed rotation speed signal Sn and torque signal τ0 provided by the torsion angle sensor and the viscous state quantity Sa calculated by the viscous state detection unit 8, the activation state quantity Sb is calculated by the state activation control unit 9; the activation state quantity Sb calculated by the state activation control unit 9 controls the high-frequency wave transmitter 10 to emit a high-frequency wave current signal Is, and the high-frequency wave current Is is added to the auxiliary torque current Ia from the torque controller 2 through the adder 11 to obtain the target current It for controlling the motor 5. The current control unit 3 controls to make the calculated target current It consistent with the current Id detected by the current detection unit 6, and outputs it as a voltage command signal Sv such as a PWM signal to the drive circuit 4 composed of an H-bridge circuit, for example, and thus outputs a drive current corresponding to the PWM signal to the motor 5. The motor 5 generates an auxiliary torque to assist the steering force provided by the driver to the steering shaft.

[0085] Based on Figure 8 the flowchart of, the operation of the electric power steering start viscous compensation control device with the above structure will be described. First, in step S101, the steering torque signal τ0, which is the output of the torsion angle sensor, is read into the microprocessor and stored in the memory. Next, in step S102, the angle signal Sm and rotation speed signal Sn read from the torsion angle sensor are stored in the memory. Next, in step S103, the auxiliary torque current Ia calculated by the torque controller 2 is read for the steering torque signal τ0, and its output is stored in the memory. Here, the torque controller 2 can also be a known method, for example, a method of calculating based on predetermined mapping data.

[0086] In step S104, for the angle signal Sm and rotation speed signal Sn read from the torsion angle sensor, the viscous state quantity Sa is calculated by the viscous state detection unit 8, and its output is stored in the memory. In step S105, for the signal τ0 of the steering torque and the rotation speed signal Sn read from the torsion angle sensor and the viscous state quantity Sa calculated by the viscous state detection unit read from the memory, the state activation quantity Sb is calculated by the state activation control unit, and its output is stored in the memory.

[0087] In step S106, for the state activation amount signal Sb read from the memory, the high-frequency wave transmitter 10 calculates the high-frequency wave current signal Is, which is stored in the memory. Then, in step S107, in the adder 11, the high-frequency wave current signal Is is added to the auxiliary torque current Ia from the torque controller 2 to determine the target current It. The operation of determining the target current It is repeatedly performed for each control sampling from the above steps S101 to S107.

[0088] Next, the high-frequency wave transmitter 10 will be described: The high-frequency wave transmitter 10 is used to transmit high-frequency oscillation waves, which can be in the form of periodic sine waves, square waves, or triangular waves, etc., with a frequency in the range of 50 Hz - 120 Hz. The activation or deactivation of the high-frequency wave transmitter 10 to transmit high-frequency oscillation waves is controlled by the activation state amount Sb. As Figure 9 shown, taking a sine wave of 50 Hz as an example, when the high-frequency wave transmitter 10 is activated, it starts to transmit high-frequency oscillation sine waves, and stops transmitting when deactivated. To ensure the smoothness of the steering start process, the amplitude of the sine wave transmitted will be gradually increased or decreased during the start and stop transmission processes. Figure 9 The amplitude of the sine wave in is only for illustration and does not represent the magnitude of the actual high-frequency wave current transmitted.

[0089] The viscous state amount detection unit of the present invention detects the viscous state amount of the electric power steering device; the activation state amount control unit is activated at the moment when viscosity occurs and deactivated in a timely manner at the moment when viscosity disappears; the high-frequency oscillation wave transmitter makes the worm and worm gear exit the viscous state in advance by transmitting high-frequency oscillation wave signals, and compensates for the viscous torque by constituting including the output of the torque controller, that is, the auxiliary torque current, and the output of the high-frequency oscillation wave transmitter, that is, the high-frequency oscillation wave signal. Compared with the prior art, the present invention can accurately detect the driver's steering torque, the motor rotation angle, and the motor rotation angular velocity, and effectively eliminate the viscous phenomenon at the moment of starting the electric steering device by controlling the high-frequency oscillation component output by the motor.

[0090] The above has described the present invention in detail through specific implementation manners and embodiments, but these do not constitute limitations to the present invention. Without departing from the principle of the present invention, those skilled in the art can also make many deformations and improvements, which should also be regarded as the protection scope of the present invention.

Claims

1. An electric power steering startup viscous compensation control device, characterized in that, Comprising: A torque sensor for detecting the steering torque of the driver; A torque controller for reading the steering torque detected by the torque sensor and calculating to obtain an auxiliary torque current; A detection unit for detecting the rotational speed signal and the rotational angle signal of the motor or the steering wheel and removing noise; A viscous state detection unit for calculating a viscous state quantity according to the noise-removed motor rotational speed signal and angle signal provided by the detection unit read in and according to a preset rule; A state activation control unit for reading the noise-removed rotational speed signal output by the position detection unit, the torque signal output by the torque sensor, and the viscous state quantity output by the viscous state detection unit to calculate an activation state quantity; A high-frequency wave transmitter for transmitting a high-frequency wave current signal according to the activation state quantity output by the state activation control unit; An adder for adding the auxiliary torque current output by the torque controller and the high-frequency wave current output by controlling the high-frequency wave transmitter to obtain a target current for controlling the motor.

2. The electric power steering startup stickiness compensation control device according to claim 1, wherein It further includes A current detection unit for detecting the current of the motor drive circuit; A current control unit for performing a consistency control process on the target current and the current detected by the current detection unit, forming a drive current and outputting it to the motor to generate an assisting torque for assisting the steering force provided by the driver to the steering shaft.

3. The electric steering start-up viscous compensation control device according to claim 1, characterized in that The preset rule in the viscous state detection unit is that when the read rotational speed signal is greater than the threshold value, it is considered that the system does not have viscosity; when the read rotational speed signal is less than the threshold value and the holding time is greater than the preset value and the angle slip amount is less than the threshold value, it is considered that the system has viscosity.

4. The electric steering start-up viscous compensation control device according to claim 1, characterized in that The state activation detection unit determines whether to activate the high-frequency wave transmitter by comparing the expected rotational speed calculated according to the steering torque signal read from the torque sensor and the current signal read from the current detection unit with the rotational speed signal read from the detection unit.

5. The electric steering start-up viscous compensation control device according to claim 4, characterized in that When the expected rotational speed is greater than the rotational speed signal, the high-frequency wave transmitter is activated.

6. The electric power steering startup stickiness compensation control device according to claim 5, characterized in that, The expected rotational speed is calculated according to the following method: Calculating a torque gradient according to the steering torque signal read from the torque sensor, then calculating a first expected rotational speed according to the torque gradient, calculating the motor output torque according to the motor current signal read from the current detection unit, and then calculating a second expected rotational speed according to the motor output torque, and taking the smaller value of the first expected rotational speed and the second expected rotational speed as the expected rotational speed.

7. The electric power steering startup stickiness compensation control device according to claim 1, characterized in that, It further includes a motor, and the detection unit is a position detection unit for detecting the rotational speed signal and the rotational angle signal of the motor.

8. The electric power steering startup viscous compensation control device according to claim 1, wherein The torque sensor is a torsion angle sensor, and the detection unit is arranged in the torsion angle sensor.

9. An electric steering start-up viscous compensation control method, characterized in that, Using the electric steering start-up viscous compensation control device according to any one of claims 1 to 8, and including the following steps: Step 1, monitoring and reading the steering torque value of the driver, the rotational angle and rotational speed value of the steering wheel; Step 2: Read the steering torque value, the rotation angle of the steering wheel, and the rotational speed value described in Step 1, and calculate the auxiliary torque current and the viscous state quantity respectively; Step 3: Read the steering torque value, the rotational speed value of the steering wheel, and the viscous state quantity, and calculate and obtain the activation state quantity; Step 4: Read the activation state quantity and calculate and obtain the high-frequency wave current; Step 5: Add the high-frequency wave current to the auxiliary torque current, and calculate and obtain the target current; Step 6: Output the target current and the drive current corresponding to the PWM signal to the motor, and the motor generates an auxiliary torque to assist the steering force provided by the driver to the steering shaft.

10. The electric power steering startup stickiness compensation control method according to claim 1, characterized in that: In Step 2, the calculation method adopts a method of calculating based on predetermined mapping data.

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