Position acquisition method and position acquisition system based on inductance type position sensor

Abstract

The embodiment of the invention provides a position acquisition method and a position acquisition system based on an inductance type position sensor. The method comprises the steps that an MCU controls an inductance type position sensor to charge and discharge through a charge and discharge control unit and receives the environment temperature collected by a temperature sensor; the MCU obtains a third terminal voltage signal in the charging and discharging process; the MCU determines the current sliding block position of the inductance type position sensor according to the slope change of the third end voltage signal; a sliding block position error corresponding to the environment temperature is obtained, the current sliding block position is calibrated according to the sliding block position error, and the calibrated sliding block position is obtained; and the MCU determines the position of a target component connected with the sliding block of the inductance type position sensor according to the position of the calibration sliding block. According to the method, the measurement value of the inductance type position sensor is corrected according to the temperature change, the measurement precision of the inductance type position sensor is improved, and accurate position and distance information is provided for an automatic driving system.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a position acquisition method and a position acquisition system based on an inductive position sensor. Background Art

[0002] Inductive position sensors can accurately measure and locate the position of target objects, playing a vital role in vehicle intelligent driving. For example, in an autonomous driving system, inductive position sensors can monitor the environment and obstacles around the vehicle in real time, providing the autonomous driving system with accurate position and distance information. This helps the autonomous driving system make correct decisions and maneuvers, thereby improving the safety and driving efficiency of the vehicle.

[0003] In the prior art, the working principle of the inductive position sensor is: the control unit controls the connection or disconnection of the charging unit, so that when the charging unit is turned on, the inductance in the inductive position sensor is charged by a preset charging power supply to obtain the terminal voltage of the inductive position sensor; then the comparison unit compares the terminal voltage with the preset reference voltage and outputs the comparison result; the control unit then determines the position of the inductive position sensor based on the comparison result.

[0004] However, since the working principle of the inductive position sensor is based on the law of electromagnetic induction, when the temperature changes, the resistance of the inductive coil and the magnetic permeability of the magnetic material on the inductive coil core will change with the temperature. Therefore, the measurement value of the inductive position sensor will deviate, affecting the measurement accuracy of the inductive position sensor, and ultimately resulting in errors in the accurate position and distance information provided to the autonomous driving system, affecting the safety and driving efficiency of the vehicle. Summary of the invention

[0005] The embodiments of the present application provide a position acquisition method and a position acquisition system based on an inductive position sensor, so as to improve the position measurement accuracy of the inductive position sensor and improve the safety and driving efficiency of the vehicle.

[0006] In a first aspect, an embodiment of the present application provides a position acquisition method based on an inductive position sensor, which is applied to a position acquisition system on a vehicle, wherein the position acquisition system includes: a microprocessor unit MCU, a charge and discharge control unit, a first comparator, a second comparator, an inductive position sensor, and a temperature sensor arranged at the inductive position sensor, wherein the MCU is connected to the charge and discharge control unit, the inductive position sensor, and the temperature sensor, the charge and discharge control unit is connected to a voltage end of the inductive position sensor, the first comparator and the second comparator are sequentially connected to the voltage end of the inductive position sensor, the first comparator is used to intercept a second end voltage signal within a preset reference voltage range from a first end voltage signal output from the voltage end, and the second comparator is used to smooth and filter the second end voltage signal to obtain a third end voltage signal, wherein the method includes:

[0007] The MCU controls the charging and discharging of the inductive position sensor through the charging and discharging control unit, and receives the ambient temperature collected by the temperature sensor;

[0008] The MCU obtains the third terminal voltage signal during the charging and discharging process;

[0009] The MCU determines the current slider position of the inductive position sensor according to the slope change of the third terminal voltage signal;

[0010] Obtaining a slider position error corresponding to the ambient temperature, and calibrating the current slider position according to the slider position error to obtain a calibrated slider position;

[0011] The MCU determines the position of a target component connected to the slider of the inductive position sensor according to the position of the calibration slider.

[0012] In a possible implementation, the charge and discharge control unit includes: a charging power supply, a first NMOS, and a second NMOS, the drain of the first NMOS is connected to the charging power supply, the gate of the first NMOS is connected to the drain of the second NMOS, the source of the first NMOS is grounded through a fourth resistor and a fifth resistor in sequence, the inductive position sensor is connected between the fourth resistor and the fifth resistor, the gate of the second NMOS is connected to the MCU through a first resistor, the drain of the second NMOS is grounded through a third resistor and a first capacitor, the source of the second NMOS is grounded, and the gate and source of the second NMOS are connected through a second resistor, and the charge and discharge control unit controls the charge and discharge of the inductive position sensor, including:

[0013] The MCU outputs a low voltage to the charge and discharge control unit to control the charge and discharge control unit to charge the inductive position sensor;

[0014] The MCU outputs a high voltage to the charge and discharge control unit to control the discharge of the inductive position sensor through the charge and discharge control unit.

[0015] In a possible implementation manner, obtaining the slider position error corresponding to the ambient temperature includes:

[0016] Calculating the temperature difference between the ambient temperature and the standard temperature, wherein the standard temperature is the temperature corresponding to when the inductive position sensor measures without error;

[0017] Calculating the product of the temperature difference and a preset unit error as the slider position error, wherein the unit error is the slider position error corresponding to a slider position error when the temperature differs from the standard temperature by a unit dimension;

[0018] The step of calibrating the current slider position according to the slider position error to obtain a calibrated slider position includes:

[0019] The sum of the slider position error and the current slider position is used as the calibration slider position.

[0020] In a possible implementation manner, the process of generating the unit error includes:

[0021] Under the standard temperature, the inductive position sensor is used to measure the position of the object at the target position to obtain a first measuring slider position;

[0022] Under different test temperatures, the inductive position sensor is used to measure the position of the object at the target position to obtain a second measuring slider position;

[0023] For each of the test temperatures, determining a position difference between a second measuring slider position and a first measuring slider position at the test temperature, and determining a test temperature difference between the test temperature and the standard temperature to determine a ratio of the position difference to the test temperature difference;

[0024] An average value of the ratios corresponding to the test temperatures is calculated as the unit error.

[0025] In a possible implementation manner, before determining the position difference between the second measuring slider position and the first measuring slider position at the test temperature, the method further includes:

[0026] Performing curve fitting on the positions of the second measuring slider corresponding to different test temperatures to obtain a fitting curve;

[0027] A second measuring slider position whose distance from the fitting curve is greater than or equal to a preset distance threshold is eliminated from the fitting curve.

[0028] In a possible implementation manner, before measuring the position of the object at the target position by the inductive position sensor at the standard temperature to obtain the first measuring slider position, the method further includes:

[0029] Determine a sensing area of ​​the position sensor to divide the sensing area into a plurality of sub-areas, and initialize the target position to one of the sub-areas;

[0030] After determining the ratio of the position difference to the test temperature difference, the method further includes:

[0031] The target area is adjusted to the next sub-area, and the step of returning to the step of measuring the position of the object at the target position by the inductive position sensor at the standard temperature to obtain the first measurement slider position.

[0032] In a possible implementation manner, the MCU controls the temperature sensor to operate when or before charging the inductive position sensor starts;

[0033] When or after the charging of the inductive position sensor is completed, the MCU controls the temperature sensor to stop working.

[0034] In a second aspect, an embodiment of the present application provides a position acquisition system on a vehicle, comprising: a microprocessor unit MCU, a charge and discharge control unit, a first comparator, a second comparator, an inductive position sensor, and a temperature sensor arranged at the inductive position sensor, the MCU is connected to the charge and discharge control unit, the inductive position sensor, and the temperature sensor, the charge and discharge control unit is connected to the voltage end of the inductive position sensor, the first comparator and the second comparator are sequentially connected to the voltage end of the inductive position sensor, the first comparator is used to intercept a second terminal voltage signal within a preset reference voltage range from a first terminal voltage signal output from the voltage end, and the second comparator is used to smooth and filter the second terminal voltage signal to obtain a third terminal voltage signal;

[0035] The MCU is further used to control the charging and discharging of the inductive position sensor through the charging and discharging control unit, and receive the ambient temperature collected by the temperature sensor;

[0036] The MCU is further used to obtain the third terminal voltage signal during the charging and discharging process;

[0037] The MCU is further used to determine the current slider position of the inductive position sensor according to the slope change of the third terminal voltage signal;

[0038] MCU, used for obtaining a slider position error corresponding to the ambient temperature, and calibrating the current slider position according to the slider position error to obtain a calibrated slider position;

[0039] The MCU determines the position of a target component connected to the slider of the inductive position sensor according to the position of the calibration slider;

[0040] The embodiment of the present application further provides a charge and discharge control unit, comprising: a charging power supply, a first NMOS, and a second NMOS, wherein the drain of the first NMOS is connected to the charging power supply, the gate of the first NMOS is connected to the drain of the second NMOS, the source of the first NMOS is connected to ground via a fourth resistor and a fifth resistor in sequence, the inductive position sensor is connected between the fourth resistor and the fifth resistor, the gate of the second NMOS is connected to the MCU via a first resistor, the drain of the second NMOS is connected to ground via a third resistor and a first capacitor, the source of the second NMOS is grounded, and the gate and source of the second NMOS are connected via a second resistor;

[0041] The MCU outputs a low voltage to the charge and discharge control unit to control the charge and discharge control unit to charge the inductive position sensor;

[0042] The MCU outputs a high voltage to the charge and discharge control unit to control the discharge of the inductive position sensor through the charge and discharge control unit.

[0043] In a vehicle position acquisition system provided in this application:

[0044] MCU, used to calculate the temperature difference between the ambient temperature and the standard temperature, where the standard temperature is the temperature corresponding to the error-free measurement of the inductive position sensor;

[0045] The MCU is further used to calculate the product of the temperature difference and a preset unit error as the slider position error, where the unit error is the slider position error corresponding to a slider position error when the temperature differs from the standard temperature by a unit dimension;

[0046] The current slider position is calibrated according to the slider position error to obtain a calibrated slider position, including:

[0047] The MCU is further configured to use the sum of the slider position error and the current slider position as the calibration slider position.

[0048] In a vehicle position acquisition system provided in this application:

[0049] The inductive position sensor is used to measure the position of an object at a target position at the standard temperature to obtain a first measuring slider position;

[0050] The inductive position sensor is further used to obtain the position of the second measuring slider by measuring the position of the object at the target position at different test temperatures;

[0051] MCU, used for determining, for each of the test temperatures, a position difference between a second measuring slider position and a first measuring slider position at the test temperature, and determining a test temperature difference between the test temperature and the standard temperature, so as to determine a ratio of the position difference to the test temperature difference;

[0052] The MCU is further used to calculate the average value of the ratios corresponding to the test temperatures as the unit error.

[0053] In a vehicle position acquisition system provided in this application:

[0054] MCU, used for performing curve fitting on the positions of the second measuring slider corresponding to different test temperatures to obtain a fitting curve;

[0055] The MCU is used to remove from the fitting curve the second measuring slider position whose distance from the fitting curve is greater than or equal to a preset distance threshold.

[0056] In a vehicle position acquisition system provided in this application:

[0057] The MCU is used to determine a sensing area of ​​the position sensor, divide the sensing area into a plurality of sub-areas, and initialize the target position to one of the sub-areas;

[0058] After determining the ratio of the position difference to the test temperature difference, the method further includes:

[0059] The MCU is used to adjust the target area to the next sub-area, and return to the step of measuring the position of the object at the target position by the inductive position sensor at the standard temperature to obtain the first measurement slider position.

[0060] In a vehicle position acquisition system provided in this application:

[0061] The MCU is used to control the temperature sensor to operate when or before charging of the inductive position sensor begins;

[0062] The MCU is further used to control the temperature sensor to stop working when or after the charging of the inductive position sensor is completed.

[0063] In a third aspect, an embodiment of the present application provides an MCU for executing the first aspect and / or various possible implementations of the first aspect as described above.

[0064] In a fourth aspect, the present application provides a vehicle, comprising a position acquisition system and / or a charge and discharge control unit on the vehicle.

[0065] The embodiment of the present application provides a position acquisition method and a position acquisition system based on an inductive position sensor, wherein the MCU controls the charging and discharging of the inductive position sensor through the charging and discharging control unit, and receives the ambient temperature collected by the temperature sensor, and then the MCU obtains the third-terminal voltage signal during the charging and discharging process, and the MCU determines the current slider position of the inductive position sensor according to the slope change of the third-terminal voltage signal, and then obtains the slider position error corresponding to the ambient temperature, and calibrates the current slider position according to the slider position error to obtain the calibrated slider position, and finally the MCU determines the position of the target component connected to the slider of the inductive position sensor according to the calibrated slider position. Compared with the prior art, in which the terminal voltage of the inductive position sensor is directly compared with a preset reference voltage and then the position of the inductive position sensor is determined according to the comparison result, the present application obtains the slider position error corresponding to the ambient temperature, and then calibrates the current slider position according to the slider position error to obtain the calibrated slider position, and finally determines the position of the target component connected to the slider of the inductive position sensor according to the obtained calibrated slider position, and calibrates the inductive position sensor using the measurement error corresponding to the temperature, thereby improving the measurement accuracy of the inductive position sensor, thereby improving the safety and driving efficiency of the autonomous driving system. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0067] Figure 1 A schematic diagram of an application scenario of a position acquisition method based on an inductive position sensor applicable to an embodiment of the present application;

[0068] Figure 2 A schematic diagram of a flow chart of a first embodiment of a position acquisition method based on an inductive position sensor provided in the present application;

[0069] Figure 3 A schematic diagram of a flow chart of a second embodiment of a position acquisition method based on an inductive position sensor provided in the present application;

[0070] Figure 4A schematic diagram of a flow chart of a third embodiment of a position acquisition method based on an inductive position sensor provided in the present application;

[0071] Figure 5 A schematic diagram of a flow chart of a fourth embodiment of a position acquisition method based on an inductive position sensor provided in the present application;

[0072] Figure 6 It is a structural schematic diagram of the position acquisition system on the vehicle;

[0073] Figure 7 It is a structural diagram of the charge and discharge control unit.

[0074] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0075] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0076] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0077] In the prior art, since the working principle of the inductive position sensor is based on the law of electromagnetic induction, when the temperature changes, the resistance of the inductive coil in the inductive position sensor and the magnetic permeability of the magnetic material on the inductive coil core will change with the temperature, thus causing the measurement value of the inductive position sensor to deviate, ultimately resulting in errors in the accurate position and distance information provided to the autonomous driving system, affecting the safety and driving efficiency of the vehicle.

[0078] Based on this, the inventive concept of this application is how to provide a position acquisition method based on an inductive position sensor, and how to correct the measured value of the inductive position sensor according to the temperature change when the temperature changes, so as to improve the measurement accuracy of the inductive position sensor. Based on this, by obtaining the ambient temperature, and calculating the slider position error corresponding to the ambient temperature according to the ambient temperature, and then calibrating the current slider position according to the slider position error, the calibration slider position is obtained, and finally the position of the target component connected to the slider of the inductive position sensor is determined according to the calibration slider position, thereby improving the measurement accuracy of the inductive position sensor and providing accurate position and distance information for the autonomous driving system.

[0079] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0080] Figure 1 The present invention is a schematic diagram of an application scenario of a position acquisition method based on an inductive position sensor applicable to an embodiment of the present application, wherein the first comparator intercepts a second terminal voltage signal within a preset reference voltage range from a first terminal voltage signal output from a voltage terminal of the inductive position sensor, and then the second comparator is used to smooth and filter the second terminal voltage signal output from the first comparator to obtain a third terminal voltage signal. Then the MCU determines the current slider position of the inductive position sensor according to the third terminal voltage signal, and then the MCU calibrates the current slider position according to the slider position error corresponding to the ambient temperature to obtain the calibration slider position, and finally the MCU determines the position of the target component connected to the slider of the inductive position sensor according to the calibration slider position.

[0081] Figure 2 A schematic diagram of a flow chart of a first embodiment of a position acquisition method based on an inductive position sensor provided in the present application, such as Figure 2 As shown, the method comprises the following steps:

[0082] S201: The MCU controls the charging and discharging of the inductive position sensor through the charging and discharging control unit, and receives the ambient temperature collected by the temperature sensor.

[0083] In the embodiment of the present application, the microcontroller unit (MCU) is connected to the charge and discharge control unit, and the charge and discharge control unit is connected to the voltage terminal of the inductive position sensor, so the MCU sends instructions to the charge and discharge control unit to instruct the charge and discharge control unit to control the charge and discharge of the inductive position sensor. And the MCU is also connected to the temperature sensor, and the MCU is used to receive the ambient temperature collected by the temperature sensor. Optionally, the temperature sensor is a thermistor, a thermocouple or other type of temperature sensitive element, which can convert the ambient temperature into an electrical signal. The MCU obtains the current ambient temperature by reading the output signal of the temperature sensor.

[0084] The MCU controls the temperature sensor to operate when or before charging the inductive position sensor.

[0085] In the embodiment of the present application, before the MCU charges the inductive position sensor or when charging starts, the MCU first sends a command to the temperature sensor to start working. After receiving the command, the temperature sensor will immediately start collecting the ambient temperature.

[0086] When or after the charging of the inductive position sensor is completed, the MCU controls the temperature sensor to stop working.

[0087] In an embodiment of the present application, when the MCU finishes charging the inductive position sensor or after charging is completed, the MCU sends an instruction to the temperature sensor to control the temperature sensor to stop working. After receiving the instruction, the temperature sensor immediately stops collecting ambient temperature information and turns off related circuits to save energy.

[0088] In an embodiment of the present application, the MCU controls the temperature sensor to start working when or before the charging of the inductive position sensor starts, and controls the temperature sensor to stop working when or after the charging of the inductive position sensor ends. The MCU controls the temperature sensor to work only when the MCU controls the charging and discharging of the inductive position sensor through the charging and discharging control unit, and controls the temperature sensor to stop working at other times, so as to reduce the power consumption of the temperature sensor, which helps to reduce the overall energy consumption of the position acquisition system on the vehicle.

[0089] S202: The MCU obtains a third terminal voltage signal during the charging and discharging process.

[0090] In an embodiment of the present application, the voltage end of the inductive position sensor is connected to a first comparator and a second comparator in sequence. The first comparator is used to intercept a second end voltage signal within a preset reference voltage range from a first end voltage signal output from the voltage end of the inductive position sensor. The second comparator is used to smooth and filter the second end voltage signal to obtain a third end voltage signal. By smoothing and filtering the second end voltage signal to remove high-frequency noise and fluctuations in the second end voltage signal, the obtained third segment voltage signal is made a smoother and more stable voltage signal. Therefore, the MCU obtains the third end voltage signal output by the second comparator during the charging and discharging process.

[0091] S203: The MCU determines the current slider position of the inductive position sensor according to the slope change of the third terminal voltage signal.

[0092] In the embodiment of the present application, the MCU calculates the slope change of the third-terminal voltage signal based on the third-terminal voltage signal obtained from the second comparator, and determines the current slider position of the inductive position sensor through the slope change of the third-terminal voltage signal.

[0093] S204: Obtaining a slider position error corresponding to the ambient temperature, and calibrating the current slider position according to the slider position error to obtain a calibrated slider position.

[0094] In the embodiment of the present application, the MCU obtains the slider position error corresponding to the ambient temperature, and then calibrates the current slider position according to the slider position error to obtain the calibrated slider position.

[0095] S205: The MCU determines the position of the target component connected to the slider of the inductive position sensor according to the position of the calibration slider.

[0096] In the embodiment of the present application, the MCU determines the position of the target component connected to the slider of the inductive position sensor according to the obtained calibration slider position, and converts the slider position into the actual position coordinates of the target component.

[0097] In the embodiment of the present application, the MCU controls the charging and discharging of the inductive position sensor through the charging and discharging control unit, and receives the ambient temperature collected by the temperature sensor, and then the MCU obtains the third terminal voltage signal during the charging and discharging process, and the MCU determines the current slider position of the inductive position sensor according to the slope change of the third terminal voltage signal, and then obtains the slider position error corresponding to the ambient temperature, and calibrates the current slider position according to the slider position error to obtain the calibration slider position, and finally the MCU determines the position of the target component connected to the slider of the inductive position sensor according to the calibration slider position. Compared with the prior art, directly comparing the terminal voltage of the inductive position sensor with the preset reference voltage, and then determining the position of the inductive position sensor according to the comparison result, the present application obtains the slider position error corresponding to the ambient temperature, and then calibrates the current slider position according to the slider position error to obtain the calibration slider position, and finally determines the position of the target component connected to the slider of the inductive position sensor according to the obtained calibration slider position, and calibrates the inductive position sensor using the measurement error corresponding to the temperature, thereby improving the measurement accuracy of the inductive position sensor, thereby improving the safety and driving efficiency of the automatic driving system.

[0098] Figure 3 The present invention provides a flow chart of a second embodiment of a method for collecting a position based on an inductive position sensor. Figure 1 Based on the illustrated embodiment, a specific implementation of step S201 is as follows:

[0099] S301: The MCU outputs a low voltage to the charge and discharge control unit to control the charge and discharge control unit to charge the inductive position sensor.

[0100] In the embodiment of the present application, when the MCU needs to control the charging of the inductive position sensor, the MCU outputs a low voltage signal to the charge and discharge control unit, and the gate voltage of the second NMOS is reduced, causing the second NMOS to be non-conductive. At this time, the gate voltage of the first NMOS is increased, and the high voltage makes the gate-source voltage of the first NMOS large enough, thereby causing the first NMOS to be conductive, and the VCC power supply charges the inductive position sensor through the first NMOS.

[0101] S302: The MCU outputs a high voltage to the charge and discharge control unit to control the discharge of the inductive position sensor through the charge and discharge control unit.

[0102] In the embodiment of the present application, when the MCU outputs a high voltage to the charge and discharge control unit, the gate voltage of the second NMOS increases, causing the second NMOS to be turned on. After the second NMOS is turned on, the gate voltage of the first NMOS is pulled down to 0V. The low voltage makes the gate-source voltage of the first NMOS insufficient to maintain its on state. Therefore, the first NMOS is not turned on, and the VCC power supply no longer supplies power to the inductive position sensor. At this time, the inductive position sensor is discharged.

[0103] The first resistor, the second resistor, the third resistor, the fourth resistor and the fifth resistor in the charge and discharge control unit are used to limit the current in the charge and discharge control unit to protect the charge and discharge control unit. The first capacitor is used to stabilize the power supply voltage to ensure the normal operation of the charge and discharge control unit circuit.

[0104] In the embodiment of the present application, the MCU outputs a low voltage to the charge and discharge control unit to control the charge and discharge control unit to charge the inductive position sensor, and the MCU outputs a high voltage to the charge and discharge control unit to control the discharge of the inductive position sensor through the charge and discharge control unit. By designing the charge and discharge control unit, the MCU accurately controls the high and low voltages to achieve precise time control of the charge and discharge process of the inductive position sensor, thereby ensuring that the inductive position sensor can accurately obtain position information when needed.

[0105] Figure 4 The present invention provides a flow chart of a method for collecting a position based on an inductive position sensor according to a third embodiment of the present invention. Figure 1 Based on the embodiment shown, the specific implementation method of obtaining the slider position error corresponding to the ambient temperature in step S204 is:

[0106] S401: Calculate the temperature difference between the ambient temperature and the standard temperature, where the standard temperature is the temperature corresponding to the error-free measurement of the inductive position sensor.

[0107] In the embodiment of the present application, the MCU stores a standard temperature in advance, and the standard temperature is the temperature corresponding to the inductive position sensor when measuring without error. After receiving the ambient temperature collected by the temperature sensor, the MCU calculates the temperature difference between the ambient temperature and the standard temperature. For example, the ambient temperature minus the standard temperature is the temperature difference between the ambient temperature and the standard temperature.

[0108] S402: Calculate the product of the temperature difference and a preset unit error as the slider position error, where the unit error is the slider position error corresponding to a difference of a unit dimension from the standard temperature.

[0109] In the embodiment of the present application, the product of the temperature difference and the preset unit error is calculated based on the obtained temperature difference and the preset unit error as the slider position error, wherein the unit error is the slider position error corresponding to the difference of a unit dimension from the standard temperature.

[0110] The current slider position is calibrated according to the slider position error to obtain the calibrated slider position, including:

[0111] S403: taking the sum of the slider position error and the current slider position as the calibration slider position.

[0112] In an embodiment of the present application, the slider position error is added to the current slider position to obtain a calibrated slider position.

[0113] In an embodiment of the present application, by calculating the temperature difference between the ambient temperature and the standard temperature, the standard temperature is the temperature corresponding to the error-free measurement of the inductive position sensor, and then calculating the product of the temperature difference and the preset unit error as the slider position error, and finally taking the sum of the slider position error and the current slider position as the calibration slider position, by calculating the temperature difference and applying the unit error for compensation, the slider position measurement error caused by changes in ambient temperature can be significantly reduced, and as the ambient temperature changes, the slider position error is calculated and applied in real time for calibration, so that the position acquisition system on the vehicle can dynamically adapt to environmental changes and maintain high-precision position measurement.

[0114] Figure 5 This is a flow chart of a fourth embodiment of a position acquisition method based on an inductive position sensor provided in the present application. Figure 4 Based on the illustrated embodiment, the process of generating the unit error includes:

[0115] The method further comprises: measuring the position of an object at a target position by using an inductive position sensor at a standard temperature, and obtaining the first measuring slider position before the first measuring slider position is obtained;

[0116] A sensing area of ​​the position sensor is determined to divide the sensing area into a plurality of sub-areas, and a target position is initialized as one of the sub-areas.

[0117] In the embodiment of the present application, the sensing area of ​​the inductive position sensor is first determined, and the sensing area is divided into multiple sub-areas to more accurately locate the target position, and the target position is initialized to one of the sub-areas as the starting point of the measurement. For example, when the sensing area of ​​the position sensor is a 100-centimeter straight line, for accurate measurement, the straight line is divided into 10 sub-areas, each sub-area is 10 centimeters, and the target position is initialized to the midpoint of the fifth sub-area, that is, 50 centimeters.

[0118] S501: Under a standard temperature, a position of an object at a target position is measured by an inductive position sensor to obtain a first measurement slider position.

[0119] In the embodiment of the present application, the position of the object at the target position is measured by the inductive position sensor at the standard temperature to obtain the first measurement slider position. For example, at the standard temperature of 25°C, the position of the object at the target position is measured by the inductive position sensor, and the first measurement slider position is 50 cm.

[0120] S502: measuring the position of an object at a target position by using an inductive position sensor at different test temperatures to obtain a second measuring slider position.

[0121] In the embodiment of the present application, different temperatures are set, and at different test temperatures, the position of the object at the target position is measured by the inductive position sensor to obtain the position of the second measurement slider. For example, the test temperature is set to 10°C, 20°C, 30°C, and 35°C, and the position of the object at the target position is measured by the inductive position sensor at different temperatures. For example, the second measurement slider position obtained at 10°C is 49.0 cm, and the second measurement slider position obtained at 20°C is 49.5 cm.

[0122] Before determining the position difference between the second measuring slider position and the first measuring slider position at the test temperature, the method further includes:

[0123] Curve fitting is performed on the positions of the second measuring slider corresponding to different test temperatures to obtain a fitting curve.

[0124] In an embodiment of the present application, curve fitting is performed on the second measurement slider positions corresponding to different test temperatures to obtain a fitting curve. Optionally, linear regression can be used to perform curve fitting on the second measurement slider positions corresponding to different test temperatures.

[0125] The second measuring slider position whose distance from the fitting curve is greater than or equal to the preset distance threshold is eliminated from the fitting curve.

[0126] In the embodiment of the present application, for the obtained fitting curve, the vertical distance from each data point to the fitting curve is calculated. All data points are traversed, and if the vertical distance from the data point to the fitting curve is greater than or equal to the second measurement slider position of the preset distance threshold, the data point is removed.

[0127] In an embodiment of the present application, curve fitting is performed on the obtained second measurement slider positions at different test temperatures, and then the second measurement slider positions whose distances from the fitting curve are greater than or equal to a preset distance threshold are eliminated to improve the data accuracy of the second measurement slider positions, thereby improving the accuracy of the calculated unit error.

[0128] S503: For each test temperature, determine the position difference between the second measurement slider position and the first measurement slider position at the test temperature, and determine the test temperature difference between the test temperature and the standard temperature to determine the ratio of the position difference to the test temperature difference.

[0129] In the embodiment of the present application, for each test temperature, the position difference between the second measuring slider position and the first measuring slider position at the test temperature is calculated, and the test temperature difference between the test temperature and the standard temperature is calculated, and then the ratio of the position difference to the test temperature difference is calculated. For example, at 20°C, the position difference is 0.5 cm, the test temperature difference is 5 cm, and the ratio of the position difference to the test temperature difference is 0.1.

[0130] After determining the ratio of the position difference and the test temperature difference, it also includes:

[0131] The target area is adjusted to the next sub-area, and the step of returning to the step of measuring the position of the object at the target position by the inductive position sensor at the standard temperature to obtain the first measurement slider position.

[0132] In the embodiment of the present application, after determining the ratio of the position difference and the test temperature difference, by adjusting the target area to the next sub-area, returning to the above step S501, that is, measuring the position of the object at the target position by the inductive position sensor at the standard temperature, and obtaining the step of the first measurement slider position, the ratio of multiple position differences and test temperature differences is obtained by repeating the calculation multiple times in a cycle to improve the measurement accuracy and reliability of the ratio of position differences and test temperature differences. Optionally, the iteration is stopped when the data volume of the ratio of the position difference and test temperature difference reaches a preset value, or the iteration is stopped when the preset number of iterations is reached.

[0133] S504: Calculate the average value of the ratios corresponding to the test temperatures as the unit error.

[0134] In the embodiment of the present application, for each test temperature, the ratio of the position difference to the test temperature difference is calculated, and then the average value of the ratio corresponding to each test temperature is taken as the unit error.

[0135] In the embodiment of the present application, the position of the object at the target position is measured by the inductive position sensor at the standard temperature to obtain the first measurement slider position, and then the position of the object at the target position is measured by the inductive position sensor at different test temperatures to obtain the second measurement slider position. For each test temperature, the position difference between the second measurement slider position and the first measurement slider position at the test temperature is determined, and the test temperature difference between the test temperature and the standard temperature is determined to determine the ratio of the position difference and the test temperature difference, and finally the average value of the ratio corresponding to each test temperature is calculated as the unit error. By measuring the position of the slider at different test temperatures and calculating the position difference with the standard temperature, the influence of temperature on the measurement accuracy of the inductive position sensor is quantified, and then the ratio of the position difference and the test temperature difference is calculated, and the average value thereof is calculated as the unit error, which can more accurately describe the average change in the slider position when the temperature changes by one degree, which is helpful to accurately compensate the measurement results according to the ambient temperature in practical applications.

[0136] Figure 6 This is a schematic diagram of the structure of the position acquisition system on the vehicle. Figure 6 As shown, the position acquisition system on the vehicle includes: a microprocessor unit MCU601, a charge and discharge control unit 602, a first comparator 603, a second comparator 604, an inductive position sensor 605, and a temperature sensor 606 arranged at the inductive position sensor;

[0137] Among them, the first comparator 603 is used to intercept the second terminal voltage signal within a preset reference voltage range from the first terminal voltage signal output from the voltage terminal, and the second comparator 604 is used to smooth and filter the second terminal voltage signal to obtain a third terminal voltage signal; MCU601 controls the charging and discharging of the inductive position sensor 605 through the charging and discharging control unit 602, and receives the ambient temperature collected by the temperature sensor 606; MCU601 obtains the third terminal voltage signal during the charging and discharging process; MCU601 determines the current slider position of the inductive position sensor 605 according to the slope change of the third terminal voltage signal; obtains the slider position error corresponding to the ambient temperature, and calibrates the current slider position according to the slider position error to obtain the calibrated slider position; MCU601 determines the position of the target component connected to the slider of the inductive position sensor 605 according to the calibrated slider position.

[0138] Figure 7 Figure 1 is a schematic diagram of the structure of the charge and discharge control unit. Figure 7 As shown, the charge and discharge control unit includes: a charging power supply 701, a first NMOS 702, a second NMOS 703, a first resistor 704, a second resistor 705, a third resistor 706, a fourth resistor 707 and a fifth resistor 708, and a first capacitor 709;

[0139] Among them, the gate of the first NMOS702 is connected to the drain of the second NMOS703, the source of the first NMOS702 is grounded through the fourth resistor 707 and the fifth resistor 708 in sequence, the inductive position sensor is connected between the fourth resistor 707 and the fifth resistor 708, the gate of the second NMOS703 is connected to the MCU through the first resistor 704, the drain of the second NMOS703 is grounded through the third resistor 706 and the first capacitor 709, the source of the second NMOS703 is grounded, and the gate and source of the second NMOS703 are connected through the second resistor 705.

[0140] The present application also provides an MCU, which is used to execute the above-mentioned position acquisition method based on an inductive position sensor.

[0141] Based on the same technical concept, the embodiment of the present application also provides a vehicle, including the position acquisition system and / or charge and discharge control unit on the above-mentioned vehicle provided in the embodiment of the present application. The vehicle provided in the embodiment of the present application can be applied to all application scenarios using the above-mentioned position acquisition system and / or charge and discharge control unit.

[0142] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A position acquisition method based on an inductive position sensor, characterized in that: A position acquisition system applied to a vehicle, the position acquisition system comprising: a microprocessor unit MCU, a charge and discharge control unit, a first comparator, a second comparator, an inductive position sensor, and a temperature sensor arranged at the inductive position sensor, the MCU being connected to the charge and discharge control unit, the inductive position sensor, and the temperature sensor, the charge and discharge control unit being connected to a voltage terminal of the inductive position sensor, the first comparator and the second comparator being connected to the voltage terminal of the inductive position sensor in sequence, the first comparator being used to intercept a second terminal voltage signal within a preset reference voltage range from a first terminal voltage signal output from the voltage terminal, the second comparator being used to perform smooth filtering on the second terminal voltage signal to obtain a third terminal voltage signal, the method comprising: The MCU controls the charging and discharging of the inductive position sensor through the charging and discharging control unit, and receives the ambient temperature collected by the temperature sensor; The MCU obtains the third terminal voltage signal during the charging and discharging process; The MCU determines the current slider position of the inductive position sensor according to the slope change of the third terminal voltage signal; Obtaining a slider position error corresponding to the ambient temperature, and calibrating the current slider position according to the slider position error to obtain a calibrated slider position; The MCU determines the position of a target component connected to the slider of the inductive position sensor according to the position of the calibration slider.

2. The method according to claim 1, characterized in that The charge and discharge control unit includes: a charging power supply, a first NMOS, and a second NMOS, wherein the drain of the first NMOS is connected to the charging power supply, the gate of the first NMOS is connected to the drain of the second NMOS, the source of the first NMOS is connected to ground via a fourth resistor and a fifth resistor in sequence, the inductive position sensor is connected between the fourth resistor and the fifth resistor, the gate of the second NMOS is connected to the MCU via a first resistor, the drain of the second NMOS is connected to ground via a third resistor and a first capacitor, the source of the second NMOS is connected to ground, and the gate and source of the second NMOS are connected via a second resistor, and the charge and discharge control unit controls the charge and discharge of the inductive position sensor, including: The MCU outputs a low voltage to the charge and discharge control unit to control the charge and discharge control unit to charge the inductive position sensor; The MCU outputs a high voltage to the charge and discharge control unit to control the discharge of the inductive position sensor through the charge and discharge control unit.

3. The method according to claim 1, characterized in that The obtaining of the slider position error corresponding to the ambient temperature includes: Calculating the temperature difference between the ambient temperature and the standard temperature, wherein the standard temperature is the temperature corresponding to when the inductive position sensor measures without error; Calculating the product of the temperature difference and a preset unit error as the slider position error, wherein the unit error is the slider position error corresponding to a slider position error when the temperature differs from the standard temperature by a unit dimension; The step of calibrating the current slider position according to the slider position error to obtain a calibrated slider position includes: The sum of the slider position error and the current slider position is used as the calibration slider position.

4. The method according to claim 3, characterized in that The generation process of the unit error includes: Under the standard temperature, the inductive position sensor is used to measure the position of the object at the target position to obtain a first measuring slider position; Under different test temperatures, the inductive position sensor is used to measure the position of the object at the target position to obtain a second measuring slider position; For each of the test temperatures, determining a position difference between a second measuring slider position and the first measuring slider position at the test temperature, and determining a test temperature difference between the test temperature and the standard temperature to determine a ratio of the position difference to the test temperature difference; An average value of the ratios corresponding to the test temperatures is calculated as the unit error.

5. The method according to claim 4, characterized in that Before determining the position difference between the second measuring slider position and the first measuring slider position at the test temperature, the method further includes: Performing curve fitting on the positions of the second measuring slider corresponding to different test temperatures to obtain a fitting curve; A second measuring slider position whose distance from the fitting curve is greater than or equal to a preset distance threshold is eliminated from the fitting curve.

6. The method according to claim 4, characterized in that Before measuring the position of the object at the target position by the inductive position sensor at the standard temperature to obtain the first measuring slider position, the method further includes: Determine a sensing area of ​​the position sensor to divide the sensing area into a plurality of sub-areas, and initialize the target position to one of the sub-areas; After determining the ratio of the position difference to the test temperature difference, the method further includes: The target area is adjusted to the next sub-area, and the step of returning to the step of measuring the position of the object at the target position by the inductive position sensor at the standard temperature to obtain the first measurement slider position.

7. The method according to claim 1, characterized in that Also includes: The MCU controls the temperature sensor to operate when or before charging of the inductive position sensor begins; When or after the charging of the inductive position sensor is completed, the MCU controls the temperature sensor to stop working.

8. A position acquisition system on a vehicle, characterized in that: The position acquisition system comprises: A microprocessor unit MCU, a charge and discharge control unit, a first comparator, a second comparator, an inductive position sensor, and a temperature sensor arranged at the inductive position sensor, the MCU is connected to the charge and discharge control unit, the inductive position sensor, and the temperature sensor, the charge and discharge control unit is connected to the voltage end of the inductive position sensor, the first comparator and the second comparator are connected to the voltage end of the inductive position sensor in sequence, the first comparator is used to intercept a second terminal voltage signal within a preset reference voltage range from a first terminal voltage signal output from the voltage end, and the second comparator is used to smooth and filter the second terminal voltage signal to obtain a third terminal voltage signal.

9. The system according to claim 8, characterized in that The charge and discharge control unit comprises: A charging power supply, a first NMOS, and a second NMOS, wherein the drain of the first NMOS is connected to the charging power supply, the gate of the first NMOS is connected to the drain of the second NMOS, the source of the first NMOS is connected to ground via a fourth resistor and a fifth resistor in sequence, the inductive position sensor is connected between the fourth resistor and the fifth resistor, the gate of the second NMOS is connected to the MCU via a first resistor, the drain of the second NMOS is connected to ground via a third resistor and a first capacitor, the source of the second NMOS is grounded, and the gate and source of the second NMOS are connected via a second resistor.

10. An MCU, characterized in that: Used to perform the method according to any one of claims 1 to 7.

11. A vehicle, characterized in that: The method comprises the position acquisition system as described in claim 8 or 9.

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