Method and system for compensating order of eps shock noise

Abstract

The application discloses an EPS vibration noise order compensation control method, comprising the following steps: S1, collecting sensor data of hand force torque, motor torque, vehicle speed and motor rotor rotation; S2, calculating a current order frequency, and determining whether to activate a compensation state according to a judgment condition; S3, constructing a state factor based on the order frequency, constructing a state matrix A and an input matrix B in combination with a preset damping coefficient; constructing a state matrix X based on a previous period and a previous two-period basic compensation torque, and constructing an input matrix U based on a current moment and input sensing signals of the previous two periods; calculating the basic compensation torque; setting the basic compensation torque to 0 in a non-activated state; S4, multiplying the basic compensation torque by a compensation gain coefficient to obtain a to-be-limited-amplitude torque; respectively searching a table to obtain a maximum compensation torque corresponding to a rotation speed and a maximum compensation torque corresponding to a vehicle speed, and obtaining a final compensation torque after limiting amplitude; and S5, outputting a target assist torque superimposed with the final compensation torque to an EPS motor, so as to offset order periodic torque fluctuation.

Description

Technical Field

[0001] This invention relates to the automotive field, and in particular to a method and system for EPS vibration and noise order compensation control. Background Technology

[0002] Existing electric power steering (EPS) products consist of a motor body and a worm gear mechanical transmission pair. The motor's slot pole structure and the meshing operation of the worm gear generate periodic frequency signals of a fixed order. When the energy of this order frequency signal is large and coincides with the inherent resonant frequency range of the vehicle, it will cause the whole vehicle to resonate. The driver can clearly feel problems such as steering wheel vibration, low-frequency noise in the car, and resonance of the vehicle floor.

[0003] Existing conventional EPS power steering control strategies only output basic steering assist torque and do not have dedicated compensation control logic designed for the periodic order fluctuations generated by the motor and worm gear. They cannot identify the order frequency conditions, cannot generate compensation torque to offset the order fluctuations in real time, and are difficult to reduce the vibration and noise defects caused by periodic torque fluctuations. Summary of the Invention

[0004] The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] The technical problem to be solved by this invention is how to reduce the defects of existing EPS systems, such as steering wheel vibration, low-frequency noise in the vehicle, and body resonance, caused by the periodic order frequency generated by the motor body and worm gear meshing easily coupling with the vehicle's resonance frequency, through the orderless vibration identification and torque compensation mechanism of the EPS system.

[0006] To solve the above-mentioned technical problems, the present invention provides an EPS vibration noise order compensation control method, which includes the following steps: S1. Data Acquisition Steps: Acquire Hand Force Torque Motor torque Speed Motor rotor speed Sensor data; S2. Calculate the current order frequency and decide whether to activate the compensation state based on the judgment conditions. S3. Basic Compensation Torque Calculation Steps: Under the activated compensation state, construct a state factor based on the order frequency, and combine it with the preset damping coefficient. Construct state matrix A and input matrix B; The state matrix X is constructed based on the basic compensation torque of the previous cycle and the previous two cycles, and the input matrix U is constructed based on the input sensing signals of the current moment and the previous two cycles. pass Calculate the basic compensation torque The base compensation torque is set to 0 in the inactive state. S4. Compensation Torque Limiting Step: Multiply the base compensation torque by the compensation gain coefficient. Obtain the torque to be limited; look up the tables to get the maximum compensation torque corresponding to the engine speed and the maximum compensation torque corresponding to the vehicle speed, and then obtain the final compensation torque after limiting. ; S5. Torque Execution Step: Output the target assist torque superimposed with the final compensation torque to the EPS motor to counteract the periodic torque fluctuations.

[0007] Preferably, in a further improved EPS vibration and noise order compensation control method, the state matrix A includes two parameters, A1 and A2, calculated using the following formula: ; ; ; The input matrix B contains two parameters, B1 and B2, and is calculated using the following formula: ; ; ; ; It calculates the state factor.

[0008] Preferably, the EPS vibration and noise order compensation control method is further improved, and the state matrix X is as follows; ; for The calculated value from the previous period, for The first two periods are calculated, where T is the period; The state matrix U is as follows; ; The input matrix Input the sensor signal at the current moment, The input sensing signal is used for the first two cycles.

[0009] Preferably, in a further improved EPS vibration and noise order compensation control method, the input sensing signal is any one of hand torque, motor torque, motor phase current, and steering wheel speed.

[0010] Preferably, in a further improvement to the EPS vibration and noise order compensation control method, the compensation activation state determination parameter is: The range is greater than 5Hz. The range is greater than 50 rpm. This is a valid value.

[0011] Preferably, the EPS vibration noise order compensation control method is further improved in that the preset damping coefficient range is greater than 0.01 and the compensation gain coefficient range is [-20~20].

[0012] Preferably, in a further improvement to the EPS vibration and noise order compensation control method, the judgment conditions include: Simultaneously determine three sets of conditions: order and frequency. Motor rotor speed and vehicle speed ; It is the minimum threshold of the order frequency. It is the minimum threshold speed of the motor rotor. It is the maximum vehicle speed threshold; When all three conditions are met, the system is considered to be in a compensated active state; otherwise, it is in an inactive state.

[0013] Preferably, in a further improved EPS vibration and noise order compensation control method, the amplitude limiting operation performs the following: Limit the torque to be limited to and The final compensation torque is obtained within the range. ; This is the maximum lookup table compensation value that varies with engine speed and vehicle speed. This is the minimum compensation value.

[0014] This invention provides an EPS vibration and noise order compensation control system for executing any of the above-described EPS vibration and noise order compensation control methods, comprising: a data acquisition module, an order compensation state identification module, an order compensation torque calculation module, an order compensation torque limiting module, and an EPS execution motor connected in sequence. The data acquisition module is used to collect hand force torque. Motor torque Speed Motor rotor speed The sensor data is then output. The order compensation state identification module is connected to the data acquisition module and is used to calculate the order frequency based on the sensor data and determine the compensation activation state, and output the state flag bit. The order compensation torque calculation module is signal-connected to the order compensation state identification module, receives the state flag bit, calculates the basic compensation torque in the active state, and outputs 0Nm basic compensation torque in the inactive state. The order compensation torque limiting module is signal-connected to the order compensation torque calculation module, performs gain scaling and upper and lower limit processing on the basic compensation torque, and outputs the final compensation torque after limiting. The EPS actuator motor is connected to the order compensation torque limiting module, receives the final compensation torque and adds it to the basic assist torque output to offset the order vibration torque fluctuation.

[0015] Preferably, the EPS vibration and noise order compensation control system is further improved, wherein the order compensation torque limiting module stores a lookup table of the maximum compensation torque that varies with vehicle speed and a lookup table of the maximum compensation torque that varies with motor rotor speed.

[0016] The working principle of the present invention is explained below based on the above technical solution; The operation of the motor and worm gear generates periodic order frequency torque fluctuations. This invention first collects the vehicle and motor operation sensor signals, converts the order frequency by speed, and identifies resonance-prone conditions by matching vehicle speed and speed thresholds. It then uses a second-order state equation model to fit the order fluctuation law and calculates the basic compensation torque to offset the fluctuations in real time. Next, it combines speed and vehicle speed to look up tables and limit the amplitude to prevent overload of the compensation torque. Finally, it adds the limited compensation torque to the EPS motor assist output to counteract the periodic order torque fluctuations, reduce the order frequency vibration energy, and avoid resonance coupling with the vehicle.

[0017] Based on the above technical solution and working principle, the present invention can achieve at least the following technical effects compared with the prior art; (1) Existing technology lacks order frequency calculation and multi-threshold joint judgment logic, and cannot distinguish the low-speed and medium-speed motor speed range that is prone to resonance. Continuous compensation throughout the process will occupy a large amount of controller computing power.

[0018] This invention uses a combination of three conditions—order frequency, motor speed, and vehicle speed—to determine whether compensation is activated only when the conditions for resonance are met. In other operating conditions, the compensation torque is set to zero, reducing the real-time computation load of the controller. This invention can accurately identify vibration-prone operating conditions and activate compensation only in the resonance risk range, thereby reducing the controller's computing power consumption.

[0019] (2) Existing technologies only use a fixed ratio gain for simple torque correction, which cannot match the periodic fluctuation law of order sinusoidal type.

[0020] This invention constructs a trigonometric function state factor based on the order frequency, establishes a second-order discrete state equation, and accurately fits the order periodic fluctuation. By introducing the historical compensation torque and historical sensor input from the first two cycles into the calculation, it can accurately follow the phase of the periodic order fluctuation, reverse the fluctuation amplitude, and significantly reduce vibration noise energy. The compensation and suppression effect is better than that of fixed ratio compensation.

[0021] (3) The existing technology does not have compensation torque limiting logic. Under high fluctuation conditions, the compensation torque is too large, which will cause sudden changes in steering wheel force and abnormal steering feel.

[0022] This invention obtains the maximum allowable compensation torque by looking up tables based on motor speed and vehicle speed, and limits the range of motor speed and vehicle speed in two dimensions. The minimum value of the two is taken as the upper limit. The bidirectional limit constraint on the compensation torque output avoids sudden changes in steering feel and system loss of control caused by the compensation torque exceeding the limit. It suppresses vibration while ensuring stable steering feel and improves the safety of system operation.

[0023] (4) The existing EPS only outputs basic assist torque and has no control logic to counteract order fluctuations. Periodic torque fluctuations are continuously transmitted to the steering wheel and body, and low-frequency order frequencies can easily trigger vehicle resonance.

[0024] This invention outputs a real-time, phase-opposite compensating torque to counteract the periodic load fluctuations caused by the motor and worm gear, reducing the vibration energy of the order frequency, thus avoiding vehicle resonance at its source and eliminating problems such as steering wheel vibration, low-frequency noise inside the vehicle, and floor resonance. Attached Figure Description

[0025] The accompanying drawings are intended to illustrate the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the invention, supplementing the description in the specification. However, the drawings are schematic diagrams not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any of the given embodiments. The drawings should not be construed as limiting or restricting the range of numerical values ​​or properties covered by exemplary embodiments of the invention. The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a schematic diagram of the EPS vibration and noise order compensation control system. Figure 2 This is a schematic diagram of the overall structure of the EPS system; Figure 3 It is a curve showing the maximum compensation torque limit as a function of vehicle speed; Figure 4 It is a curve of the maximum compensation torque as the motor rotor speed changes. Detailed Implementation

[0027] The following specific embodiments illustrate the implementation of the present invention. 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 various 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, in the absence of conflict, the following embodiments and 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 to the specific embodiments set forth 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 embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements. Throughout the drawings, the same reference numerals always denote the same elements.

[0028] First embodiment; This invention provides a method for order compensation and control of EPS vibration and noise, comprising the following steps: Step S1: Collect hand force torque Motor torque Speed Motor rotor speed Sensor data; Step S2, Identification of Compensation Activation Status: 1) For example, set a fixed parameter: minimum order frequency threshold. The minimum speed threshold for the motor is 20Hz. The maximum vehicle speed threshold is 600 rpm. The speed is 30 km / h. The order to be optimized is... It is of order 2; 2) Formula for calculating order frequency: ; 3) Judgment conditions: Order frequency Motor rotor speed and vehicle speed ; It is the minimum threshold of the order frequency. It is the minimum threshold speed of the motor rotor. It is the maximum vehicle speed threshold; When all three conditions are met, the compensation activation state flag is set to 1; otherwise, the inactive state flag is set to 0. Taking actual operating conditions as an example: motor rotor speed The speed is 901 rpm. Substitute this into the formula to calculate. If all the judgment conditions are met, the compensation activation flag is set to 1. S3. Under the compensated state activation condition, a state factor is constructed based on the order frequency, combined with a preset damping coefficient. Construct state matrix A and input matrix B. It is 0.5; Calculate state factors Exemplary It is 30.03Hz, calculated as follows It is 0.00946; Solving for state matrices A1 and A2 forms matrix A, and solving for state matrices B1 and B2 forms matrix B: ; ; ; The input matrix B contains two parameters, B1 and B2, and is calculated using the following formula: ; ; ; The state matrix X is as follows; The initial calculation cycle has no historical values, and the initial value of the X matrix is ​​0; for The calculated value from the previous period, for The first two periods are calculated, where T is the period; The state matrix U is as follows; An exemplary input signal U is selected as the hand force torque. In this example, the real-time hand force torque It is 2Nm. =0; The input matrix Input the sensor signal at the current moment, The input sensing signal is used for the first two cycles.

[0029] pass Calculate the basic compensation torque The initial period X is 0, which simplifies to The calculated value is 0.089 Nm; the base compensation torque is set in the inactive state. =0; S4. Multiply the base compensation torque by the compensation gain coefficient. Obtain the torque to be limited. Set it to 0.8; look up the tables to obtain the maximum compensated torque corresponding to the engine speed and the maximum compensated torque corresponding to the vehicle speed. This is the maximum lookup table compensation value that varies with engine speed and vehicle speed. For the minimum compensation value, Limit the torque to be limited to and Within the range, the final compensation torque is obtained. ; S5. Output the target assist torque to the EPS motor, which is superimposed with the final compensation torque, to counteract the periodic torque fluctuations.

[0030] Second embodiment; like Figure 1 As shown, the present invention provides an EPS vibration and noise order compensation control system, comprising: a data acquisition module, an order compensation state identification module, an order compensation torque calculation module, an order compensation torque limiting module, and an EPS actuator motor; each module is connected to the other by electrical signals in sequence.

[0031] Data acquisition module: collects hand force and torque. Motor torque Speed Motor rotor speed And transmit it to the order compensation state recognition module; The order compensation state recognition module has a built-in order frequency calculation formula and triple threshold judgment logic, and outputs a 0 / 1 binary state flag to the order compensation torque calculation module. Order-compensated torque calculation module: Includes a built-in second-order state equation calculation program; receives state flags; when the flag is 1, the calculation proceeds according to the steps of the first embodiment. When the flag is 0, the output is 0 or Nm; Order-compensated torque limiting module: Built-in speed-torque lookup table ( Figure 4 As shown), vehicle speed-torque lookup table ( Figure 3 As shown), perform gain scaling and bidirectional limiting operations, and output... ; EPS actuator motor: Receives the compensation torque after amplitude limiting, and superimposes it with the basic assist torque to drive the steering mechanism, thus offsetting the order fluctuation.

[0032] The following improvements can be made as an option: 1. The input matrix U, except for the hand force torque, can be replaced with motor torque, motor phase current, and steering wheel speed without changing the core calculation logic; 2. Can be modified according to the motor slot poles and worm gear structure. It is suitable for vibration suppression requirements of different orders, such as 4th, 8th, 24th, and 1st order. 3. Damping coefficient Compensation gain coefficient Each threshold frequency / speed / vehicle speed can be adjusted according to the vehicle calibration requirements without changing the overall control process.

[0033] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless explicitly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0034] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for order compensation control of EPS vibration and noise, characterized in that, Includes the following steps: S1. Collect sensor data on hand force torque, motor torque, vehicle speed, and motor rotor speed; S2. Calculate the current order frequency and decide whether to activate the compensation state based on the judgment conditions. S3. Under the condition of compensation state activation, state factors are constructed based on the order frequency, and state matrix A and input matrix B are constructed in combination with the preset damping coefficient. The state matrix X is constructed based on the basic compensation torque of the previous cycle and the previous two cycles, and the input matrix U is constructed based on the input sensing signals of the current moment and the previous two cycles. pass Calculate the base compensation torque; in the inactive state, the base compensation torque is set to 0. S4. Multiply the basic compensation torque by the compensation gain coefficient to obtain the torque to be limited; The maximum compensation torque corresponding to the engine speed and the maximum compensation torque corresponding to the vehicle speed are obtained by looking up the tables respectively, and the final compensation torque is obtained after limiting. S5. Output the target assist torque to the EPS motor, which is superimposed with the final compensation torque, to counteract the periodic torque fluctuations.

2. The EPS vibration and noise order compensation control method according to claim 1, characterized in that: The state matrix A contains two parameters, A1 and A2, and is calculated using the following formula: ； ； ； The input matrix B contains two parameters, B1 and B2, and is calculated using the following formula: ； ； ； ； It calculates the state factor.

3. The EPS vibration noise order compensation control method according to claim 1, characterized in that: The state matrix X is as follows; ； for The calculated value from the previous period, for The first two periods are calculated, where T is the period; The state matrix U is as follows; ； The input matrix Input the sensor signal at the current moment, The input sensing signal is used for the first two cycles.

4. The EPS vibration noise order compensation control method according to claim 1, characterized in that: The input sensing signal can be any one of the following: hand torque, motor torque, motor phase current, or steering wheel speed.

5. The EPS vibration and noise order compensation control method according to claim 1, characterized in that, The parameters for determining the compensation activation state are: The range is greater than 5Hz. The range is greater than 50 rpm. This is a valid value.

6. The EPS vibration and noise order compensation control method according to claim 1, characterized in that, The preset damping coefficient ranges from greater than 0.01, and the compensation gain coefficient ranges from -20 to 20.

7. The EPS vibration and noise order compensation control method according to claim 1, characterized in that, The judgment conditions include: Simultaneously determine three sets of conditions: order and frequency. Motor rotor speed and vehicle speed ; It is the minimum threshold of the order frequency. It is the minimum threshold speed of the motor rotor. It is the maximum vehicle speed threshold; When all three conditions are met, the system is considered to be in a compensated active state; otherwise, it is in an inactive state.

8. The EPS vibration and noise order compensation control method according to claim 1, characterized in that, The amplitude limiter performs the following operations: Limit the torque to be limited to and The final compensation torque is obtained within the range. ; This is the maximum lookup table compensation value that varies with engine speed and vehicle speed. This is the minimum compensation value.

9. An EPS vibration noise order compensation control system, characterized in that, The EPS vibration and noise order compensation control method according to any one of claims 1-6 comprises: a data acquisition module, an order compensation state identification module, an order compensation torque calculation module, an order compensation torque limiting module, and an EPS execution motor connected in sequence. The data acquisition module is used to collect hand force torque. Motor torque Speed Motor rotor speed Sensing data and outputting it; The order compensation state identification module is connected to the data acquisition module and is used to calculate the order frequency based on the sensor data and determine the compensation activation state, and output the state flag bit. The order compensation torque calculation module is signal-connected to the order compensation state identification module, receives the state flag bit, calculates the basic compensation torque in the active state, and outputs 0Nm basic compensation torque in the inactive state. The order compensation torque limiting module is signal-connected to the order compensation torque calculation module, performs gain scaling and upper and lower limit processing on the basic compensation torque, and outputs the final compensation torque after limiting. The EPS actuator motor is connected to the order compensation torque limiting module, receives the final compensation torque and adds it to the basic assist torque output to offset the order vibration torque fluctuation.

10. The EPS vibration and noise order compensation control system according to claim 9, characterized in that: The order-compensation torque limiting module stores a lookup table for the maximum compensation torque that varies with vehicle speed and a lookup table for the maximum compensation torque that varies with motor rotor speed.

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