A closed-loop control signal detection method for a wire-controlled steering actuator

Abstract

The present invention discloses a closed-loop control signal detection method for a wire-controlled steering actuator, which relates to the field of control signal detection for wire-controlled steering actuators, and aims to solve the problem in the prior art that the detection accuracy cannot be further improved when the accuracy of the position sensor is limited. The technical solution adopted is to use a position sensor to detect the initial position of an action component, and use the rotor position change detected by the motor rotor position sensor of the controller motor assembly, and convert the displacement of the action component by combining the ratio of the motor rotor position change and the position change of the action component brought about by it, and calculate the position information after the position change by superimposing the displacement on the initial position. By combining the detection result of the position sensor with the detection result of the motor rotor position sensor with higher accuracy, the accuracy limitation of the position sensor can be broken through, thereby improving the accuracy and reliability of the detection, and facilitating the precise control of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of control signal detection for a wire-controlled steering actuator, and in particular to a closed-loop control signal detection method for a wire-controlled steering actuator. Background Art

[0002] At present, most new domestic vehicles use electric power steering systems, which can be divided into column-type electric power steering systems, gear-type electric power steering systems, and rack-type electric power steering systems according to the different positions of the power-assisting mechanism in the steering system. In the future, most high-level autonomous driving vehicles will use wire-controlled steering actuators developed on the basis of gear-type or rack-type electric steering systems. The precise control of the wire-controlled actuator is based on the precise detection of the position of the moving parts. The existing detection method is to detect through position sensors or angle sensors, but when the accuracy of the sensor is limited, the detection accuracy of the existing detection method will also be limited, which is not conducive to higher-precision detection and control needs. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a closed-loop control signal detection method for a wire-controlled steering actuator, which can effectively solve the problems in the background technology.

[0004] In order to achieve the above object, the present invention discloses a closed-loop control signal detection method for a wire-controlled steering actuator, and the technical solution adopted is to include the following steps:

[0005] Step 1: Power on the steer-by-wire actuator to get the maximum measurement range of the position sensor. The output signal of the motor rotor position sensor of the controller motor assembly has a maximum measurement range of 360° and shows periodic changes, and the change period is °, the change cycle of the motor rotor position sensor is °The maximum position change of the action component corresponding to each unit cycle can be obtained ;

[0006] Step 2: Get control signal information through position sensor detection at the moment of power-on , The motor rotor position sensor of the controller motor assembly detects the position information of the motor rotor. , according to the position information of the motor rotor Get the position of the action component corresponding to the current motor rotor position ;like ≤ , indicating that according to the current range of the displacement sensor, the displacement of the action component can be detected within the range, then step 2 is performed followed by step 3 and step 4; otherwise, step 5 to step 8 are performed;

[0007] Step 3: After the action component moves and its position changes, the position information after the action is detected by the position sensor ; The position information of the motor rotor is obtained by detecting the motor rotor position sensor of the controller motor assembly , according to the position information of the motor rotor Get the position of the action component corresponding to the current motor rotor position , then the current action component position ,in is the initial position, It is the displacement detected by the motor rotor position sensor. The sum of the two is the position after the action, the current position of the action component The initial datum for the next displacement calculation;

[0008] Step 4: The device continues to operate. After the action component is activated, the motor rotor position sensor of the controller motor assembly detects the increment of the motor rotor position and compares it with the action component position obtained in step 2. Superposition is performed to obtain subsequent position information until the action of the action component is completely completed;

[0009] Step 5: After the action component moves and its position changes, the position information after the action is detected by the position sensor ; The position information of the motor rotor is obtained by detecting the motor rotor position sensor of the controller motor assembly ; and obtain the control signal information change of the position sensor and the motor rotor position signal information change of the controller motor assembly ; According to the change of the motor rotor position signal information of the controller motor component Get the corresponding displacement change of the action component ;

[0010] Step 6: Calculate the number of complete cycles that the motor rotor position sensor passes through , the displacement T corresponding to each complete cycle and the number of complete cycles Multiplying them gives the total displacement corresponding to the number of complete cycles passed, plus , That is, the displacement in the last incomplete cycle, and the absolute position information within the current control signal range can be obtained. .

[0011] As a preferred technical solution of the present invention, in step 1, the position sensor is a linear displacement sensor or an angle sensor. The displacement sensor can be used to detect the movement of the linear motion component, and the angle sensor can be used to detect the movement of the rotational motion component.

[0012] As a preferred technical solution of the present invention, the ratio of the motor rotor position change of the controller motor assembly to the position change of the action component is , then the motor rotor position corresponds to the position of the action component .

[0013] As a preferred technical solution of the present invention, in step 1, ; In step 2, ; In the step 3, .

[0014] As a preferred technical solution of the present invention, in step 5, after the action component is actuated, the motor rotor position detected by the motor rotor position sensor at the previous moment is recorded as ,but , and then get .

[0015] As a preferred technical solution of the present invention, in step 6, if the position sensor is a linear displacement sensor, then for , according to the change in the control signal information of the position sensor The maximum position change of the moving part corresponding to each unit cycle of the motor rotor position sensor Get the number of cycles that the motor rotor position sensor has gone through during this action , rounded down to get the number of complete cycles passed ; By calculating the number of complete cycles and the displacement of the last incomplete cycle, the overall displacement of this action can be obtained. .

[0016] As a preferred technical solution of the present invention, in step 6, if the position sensor is an angle sensor, the maximum measuring stroke of its output signal is 360°, showing periodic changes, and its maximum measuring stroke is That is its change cycle, take and The least common multiple of , the output of the device is defined as 0 when the steering is in the middle position, then the control signal range is ; Simultaneous measurement and The obtained combination uniquely corresponds to a position information within the range of the control signal. , ,pass The number of cycles of the angle sensor in this action can be obtained , rounded down to get the number of complete cycles passed , by calculating the number of complete cycles and the displacement of the last incomplete cycle, the overall displacement of this action can be obtained. .

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention can break through the accuracy limitation of the position sensor by combining the detection results of the position sensor with the detection results of the motor rotor position sensor with higher accuracy. The current position can be obtained by adding the position offset to the initial position, and can be mutually verified with the detection results of the position sensor. Therefore, without changing the structural composition, the detection accuracy is improved through the information fusion method, which facilitates the precise control of the device.

[0018] Furthermore, by fusing information between the position sensor and the motor rotor position sensor, when either the position sensor or the motor position sensor temporarily fails or cannot be automatically reset, the other sensor can be used in the device as a backup sensor for the faulty sensor for a short period of time, giving the driver the opportunity to stop by the roadside, troubleshoot or call for help without losing functionality, thereby improving the overall reliability of the wire-controlled steering actuator. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1

[0021] This embodiment discloses a first implementation mode of the present invention, and the adopted technical solution is to include the following steps:

[0022] Step 1: Power on the steer-by-wire actuator to obtain the maximum measurement stroke of the position sensor (linear displacement sensor) Right now ) and the output signal of the motor rotor position sensor of the controller motor assembly. The maximum measurement stroke of the motor rotor position sensor of the controller motor assembly is 360°, showing periodic changes, and the change period is Tb °, the change cycle of the motor rotor position sensor is Tb °The maximum position change of the action component corresponding to each unit cycle can be obtained Tc , assuming that the ratio of the motor rotor position change distance of the controller motor assembly to the displacement of the rack is ,but ;

[0023] Step 2: When the wire-controlled steering actuator is powered on, the control signal information is obtained through the position sensor detection. , as the initial reference position reference; the motor rotor position sensor of the controller motor assembly detects the position information of the motor rotor , then the rack position corresponding to the current motor rotor position is obtained : at this time, is the initial position of the rack detected by the linear displacement sensor, The initial position of the rack detected by the motor rotor position sensor;

[0024] Compare and ,Discover ;

[0025] Step 3: After the rack is displaced, the position information after the displacement is detected by the linear displacement sensor. ; The position information of the motor rotor is obtained by detecting the motor rotor position sensor of the controller motor assembly , according to the position information of the motor rotor Get the rack position corresponding to the current motor rotor position : The current rack position It can be obtained by adding the displacement change to the initial position: Current rack position The initial reference for the next displacement calculation is calculated by By superimposing the next displacement increment, the position information after displacement can be obtained until the steering action is completed.

[0026] Example 2

[0027] The difference between this embodiment and embodiment 1 is that the position sensor is an angle sensor, the maximum measuring stroke of its output signal is 360°, showing periodic changes, and its maximum measuring stroke is That is its changing cycle, the moving parts are the lead screw nut, It is the turning angle information detected by the turning angle sensor.

[0028] Example 3

[0029] This embodiment discloses a third implementation mode of the present invention, and the technical solution adopted is to include the following steps:

[0030] Step 1: Power on the steer-by-wire actuator to obtain the maximum measurement stroke of the position sensor (linear displacement sensor) Right now ) and the output signal of the motor rotor position sensor of the controller motor assembly. The maximum measurement stroke of the motor rotor position sensor of the controller motor assembly is 360°, showing periodic changes, and the change period is Tb °, the change cycle of the motor rotor position sensor is Tb °The maximum position change of the action component corresponding to each unit cycle can be obtained Tc , assuming that the ratio of the motor rotor position change distance of the controller motor assembly to the displacement of the rack is ,but ;

[0031] Step 2: When the wire-controlled steering actuator is powered on, the control signal information is obtained through the position sensor detection. , as the initial reference position reference; the motor rotor position sensor of the controller motor assembly detects the position information of the motor rotor , then the rack position corresponding to the current motor rotor position is obtained : at this time, is the initial position of the rack detected by the linear displacement sensor, The initial position of the rack detected by the motor rotor position sensor;

[0032] Compare and ,Discover ;

[0033] Step 3: After the action component moves and its position changes, the position information after the action is detected by the position sensor ; The position information of the motor rotor is obtained by detecting the motor rotor position sensor of the controller motor assembly ; The motor rotor position detected by the motor rotor position sensor at the last moment is recorded as Right now ), and obtain the control signal information change of the position sensor ( ) and the motor rotor position signal information change of the controller motor assembly ( ); According to the change of the motor rotor position signal information of the controller motor component Get the corresponding displacement change of the action component ( );

[0034] Step 4: According to the change in the control signal information of the position sensor The maximum position change of the moving part corresponding to each unit cycle of the motor rotor position sensor Get the number of cycles that the motor rotor position sensor has gone through during this action ( ), rounded down to get the number of complete cycles passed ;but .

[0035] Example 4

[0036] The difference between this embodiment and embodiment 3 is that the position sensor is an angle sensor, the maximum measuring stroke of its output signal is 360°, showing periodic changes, and its maximum measuring stroke is That is its changing cycle, the moving parts are the lead screw nut, It is the turning angle information detected by the turning angle sensor.

[0037] Step 4, take and The least common multiple of , the output of the device is defined as 0 when the steering is in the middle position, then the control signal range is ; Simultaneous measurement and The obtained combination uniquely corresponds to a position information within the range of the control signal. ( ), the displacement detected by the motor rotor position sensor and the change cycle of the displacement sensor The number of cycles of the motor rotor position sensor in this action can be obtained ( ), rounded down to get the number of complete cycles passed ,but .

[0038] Comparative Example 1:

[0039] The detection result of the linear displacement sensor is directly used as the detection result of the position of the action component of the wire-controlled steering actuator.

[0040] Compare the accuracy of Example 1 with that of Comparative Example 1:

[0041] Comparative Example 1: The existing rack linear displacement sensor has an accuracy of 0.3mm and a stroke of 72mm;

[0042] Embodiment 1: The measurement accuracy of the existing motor rotor position sensor is 0.00013°.

[0043] The reduction ratio between the small pulley and the motor shaft is 1.

[0044] The reduction ratio between the small pulley and the large pulley is 3.37.

[0045] The reduction ratio between the large pulley and the nut is 1.

[0046] The pitch between the nut and the screw is 3mm.

[0047] The reduction ratio between the screw and the rack is 1.

[0048] Therefore, the measurement accuracy of the motor rotor position sensor is converted to the rack, and its accuracy is:

[0049] 0.00013 / 3.37 / 360*3=0.0000003mm.

[0050] It can be seen from this that the detection accuracy of Example 1 is much higher than that of Comparative Example 1.

[0051] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A closed-loop control signal detection method for a wire-controlled steering actuator, characterized in that: The following steps are involved: Step 1: Power on the steer-by-wire actuator to get the maximum measurement range of the position sensor. The output signal of the motor rotor position sensor of the controller motor assembly has a maximum measurement range of 360° and shows periodic changes, and the change period is °, the change cycle of the motor rotor position sensor is °The maximum position change of the action component corresponding to each unit cycle can be obtained ,like ≤ , then proceed to step 2 and then to step 3 and step 4; otherwise, proceed to step 5 to step 8; Step 2: Get control signal information through position sensor detection at the moment of power-on , The motor rotor position sensor of the controller motor assembly detects the position information of the motor rotor. , according to the position information of the motor rotor Get the position of the action component corresponding to the current motor rotor position ; Step 3: After the action component moves and its position changes, the position information after the action is detected by the position sensor ; The position information of the motor rotor is obtained by detecting the motor rotor position sensor of the controller motor assembly , according to the position information of the motor rotor Get the position of the action component corresponding to the current motor rotor position , then the current action component position , current action component position The initial datum for the next displacement calculation; Step 4: The device continues to operate. After the action component is activated, the motor rotor position sensor of the controller motor assembly detects the increment of the motor rotor position and compares it with the action component position obtained in step 2. Superposition is performed to obtain subsequent position information until the action of the action component is completely completed; Step 5: After the action component moves and its position changes, the position information after the action is detected by the position sensor ; The position information of the motor rotor is obtained by detecting the motor rotor position sensor of the controller motor assembly ; and obtain the control signal information change of the position sensor and the motor rotor position signal information change of the controller motor assembly ; According to the change of the motor rotor position signal information of the controller motor component Get the corresponding displacement change of the action component ; Step 6: Calculate the number of complete cycles that the motor rotor position sensor passes through , the displacement T corresponding to each complete cycle and the number of complete cycles Multiply and add , you can get the absolute position information within the current control signal range .

2. The closed-loop control signal detection method of a wire-controlled steering actuator according to claim 1, characterized in that: In step 1, the position sensor is a linear displacement sensor or a rotation angle sensor.

3. The closed-loop control signal detection method of the wire-controlled steering actuator according to claim 2, characterized in that: Assume that the ratio of the motor rotor position change of the controller motor assembly to the position change of the action component is , then the motor rotor position corresponds to the position of the action component .

4. The closed-loop control signal detection method for a steer-by-wire actuator according to claim 3, characterized in that: In the step 1, ; In step 2, ; In the step 3, .

5. The closed-loop control signal detection method of a wire-controlled steering actuator according to claim 3, characterized in that: In step 5, after the action component is actuated, the motor rotor position detected by the motor rotor position sensor at the previous moment is recorded as ,but , and then get .

6. The closed-loop control signal detection method for a steer-by-wire actuator according to claim 5, characterized in that: In step 6, if the position sensor is a linear displacement sensor, then for , according to the change in the control signal information of the position sensor The maximum position change of the moving part corresponding to each unit cycle of the motor rotor position sensor Get the number of cycles that the motor rotor position sensor has gone through during this action , rounded down to get the number of complete cycles passed ;but .

7. The closed-loop control signal detection method for a steer-by-wire actuator according to claim 5, characterized in that: In step 6, if the position sensor is an angle sensor, the maximum measuring stroke of its output signal is 360°, showing periodic changes, and its maximum measuring stroke is That is its change cycle, take and The least common multiple of , the output of the device is defined as 0 when the steering is in the middle position, then the control signal range is ; Simultaneous measurement and The obtained combination uniquely corresponds to a position information within the range of the control signal. , ,pass The number of cycles of the angle sensor in this action can be obtained , rounded down to get the number of complete cycles passed ,but .