PTS Sensor Stroke Calibration Method

Abstract

The present invention discloses a method for calibrating the stroke of a PTS sensor, which includes: reading the current position of the PTS sensor and recording data. If the PTS sensor data is outside the mechanical range of the ECU system, the calibration fails; repeatedly advancing the pedal push rod by a fixed step length multiple times and then repeating step S2 until the feedback force of the pedal push rod is greater than the pedal force requirement of the ECU system. Read the current position value of the PTS sensor and record the data. If the data is outside the mechanical range of the ECU system, the calibration fails; sort the recorded data in the order of recording and fill it into an array for verification, form a fitting curve from all the PTS sensor stroke calibration point data and then store it; advance the pedal push rod by a fixed step length again. If the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is within the allowable error range, the PTS sensor position value is the data on the fitting curve closest to the current position value, and calculate the stroke value. If the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is outside the allowable error range, the calibration fails.

Description

Technical Field

[0001] The present invention relates to the field of automobiles, and particularly to a method for calibrating the travel of a PTS sensor. Background Art

[0002] A PTS sensor (Pedal Travel Sensor) is a Hall sensor mainly used to measure the displacement travel of the pedal when the driver steps on the pedal. This measurement data has wide applications and usually has high precision requirements. For example, the ECU of the braking control system in the vehicle chassis domain usually needs to collect the displacement travel data of the brake pedal to judge the driver's braking intention, and the ECU provides corresponding braking assistance according to the driver's intention. Due to the limited space inside the vehicle cab, the pedal travel is usually only between a few millimeters and dozens of millimeters. If the actual measurement value of the sensor differs greatly from the theoretical value required for ECU control, there will be a situation of misinterpreting the driver's intention. Taking the brake pedal as an example, if the measured value of the sensor is much smaller than the actual travel value of the brake pedal, there will be a situation of insufficient vehicle braking force, resulting in an extended braking distance of the vehicle, thus generating a safety risk. Therefore, the measured value of the PTS sensor and the actual travel value of the brake pedal need to be as close as possible. Since the magnetic field generated by a single magnet is difficult to meet the sensor measurement accuracy requirements, when in the magnetic field generated by multiple magnets at different positions, simply performing zero calibration will result in a large error at a large travel, affecting vehicle safety and increasing the safety risk of the vehicle.

[0003] Chinese Patent CN202111347635.5 discloses a method for calibrating an accelerator pedal, which is used to correct the correspondence between the accelerator pedal and the acceleration driving force and the deceleration braking force in the single-pedal mode. On the basis of linearly calibrating the accelerator pedal opening and the acceleration driving force and the deceleration braking force, a correction parameter related to the change rate of the accelerator pedal opening is introduced. When the change rate of the accelerator pedal opening is fast, a stronger acceleration driving force or deceleration braking force is provided. This technical solution still cannot effectively solve the technical problem of the difference between the measured value of the PTS sensor and the actual travel value of the brake pedal.

[0004] Chinese patent CN202210697670.8 discloses a brake pedal calibration method, which includes obtaining the zero-position sensor signal value and zero-position travel of the brake pedal in its initial zero-position state; obtaining the current travel of the brake pedal, and determining the brake pedal travel change based on the zero-position travel and current travel; inputting the travel change into a preset calibration model to obtain the current sensor signal change value of the vehicle's brake pedal; superimposing the current sensor signal change value with the zero-position sensor signal value, and determining the superimposed sensor signal value as the calibrated sensor signal value. This technical solution still fails to effectively resolve the technical problem of discrepancies between the PTS sensor measurement value and the actual brake pedal travel value caused by the magnetic field generated by multiple magnets in different positions. Summary of the Invention

[0005] The Summary of the Invention introduces a series of simplified concepts, which are simplifications of existing technologies in the field and are further described in detail in the Detailed Description of the Invention. The Summary of the Invention is not intended to define the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] The technical problem to be solved by the present invention is to provide a PTS sensor stroke calibration method which can avoid large errors in long stroke calibration of the PTS sensor caused by magnetic fields generated by multiple magnets in different positions.

[0007] To solve the above technical problems, the present invention provides a PTS sensor stroke calibration method, comprising the following steps:

[0008] S1, determine whether the calibration conditions are met, if not, exit the calibration;

[0009] S2, read the current position of the PTS sensor and record the data. If the PTS sensor data is outside the mechanical range of the ECU system, the calibration data is cleared and a calibration failure prompt is displayed;

[0010] S3: Repeat step S2 after repeatedly advancing the pedal push rod by a fixed step length until the pedal push rod feedback force exceeds the pedal force requirement of the ECU system. Then, read the current position value of the PTS sensor and record the data. If the data is outside the mechanical range of the ECU system, clear the calibration data and prompt calibration failure.

[0011] S4, sorting the recorded data in the order of recording, filling it into an array and verifying it, forming a fitting curve for all the PTS sensor travel calibration point data and then storing it;

[0012] S5: The ECU is powered off and restarted, and the pedal push rod is moved forward again by a fixed step length. If the difference between the PTS sensor stroke value and the actual pedal push rod stroke value is within the allowable error range, the PTS sensor position value is the data closest to the current position value on the fitting curve, and the calculated stroke value is:

[0013] Travel value = position value - calibration zero point value, record the success of this PTS calibration, and end PTS calibration;

[0014] If the difference between the PTS sensor stroke value and the actual pedal push rod stroke value is outside the allowable error range, the calibration data will be cleared and a calibration failure will be prompted.

[0015] Optionally, the PTS sensor stroke calibration method is further improved to calibrate data of multiple PTS sensor stroke calibration points, wherein the calibration points include: PTS sensor stroke zero point, PTS sensor stroke maximum value and multiple stroke intermediate measurement points, and the distance between two stroke intermediate measurement points is a fixed step size.

[0016] Optionally, the PTS sensor stroke calibration method is further improved, and the fixed step range is 1 mm-50 mm.

[0017] Optionally, the PTS sensor stroke calibration method can be further improved, and the calibration conditions include:

[0018] Enter EOL mode, clear previous calibration data, and send periodic messages to ensure the device is online.

[0019] Optionally, the PTS sensor stroke calibration method can be further improved by using the following method for calibration:

[0020] Compare each element in the array, and pass the check if the value of the previous array element is less than the value of the next array element.

[0021] Optionally, the PTS sensor stroke calibration method can be further improved. When implementing step S5, the pedal push rod is advanced by a fixed step length multiple times to determine whether the difference between the PTS sensor stroke value and the actual pedal push rod stroke value is within the allowable error range.

[0022] Optionally, the PTS sensor stroke calibration method can be further improved. If the current position value of the PTS sensor is less than the minimum value of the calibration data in the stored data, or greater than the maximum value of the calibration data in the stored data, the stroke value is recorded as 0, which is an invalid stroke.

[0023] Different from traditional calibration methods, in addition to calibrating the zero point, this invention calibrates the maximum value and multiple intermediate measurement points. Connecting the sensor data corresponding to each calibration point can obtain the corresponding calibration fitting curve. Move the pedal push rod forward by a fixed step length again. If the difference between the PTS sensor travel value and the actual travel value of the pedal push rod is within the error tolerance range, the PTS sensor position value is the data on the fitting curve closest to the current position value, and the travel value is calculated.

[0024] Traditional calibration methods usually need to consider the number of magnets and the magnet installation positions, and often adopt different calibration methods according to different magnetic field distributions. This invention is not affected by the magnet installation positions. The difference between the position value corresponding to the sensor data and the zero point position value is the actual pedal travel value, and the travel value = position value - calibration zero point value. This invention can avoid changing the calibration method due to different magnetic field distributions, and the entire calibration process can be standardized, avoiding uneven product performance caused by the technical level of designers. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings of this invention are intended to show the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments according to this invention, and supplement the description in the specification. However, the drawings of this invention are schematic diagrams not drawn to scale, and thus may not accurately reflect the precise structures or performance characteristics of any given embodiment. The drawings of this invention should not be construed as limiting or restricting the scope of the numerical values or properties covered by the exemplary embodiments according to this invention. The following further details this invention in conjunction with the drawings and specific embodiments:

[0026] Figure 1 is the flow diagram of this invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following specific embodiments illustrate the implementation manners of this invention. Those skilled in the art can fully understand the other advantages and technical effects of this invention from the content disclosed in this specification. This invention can also be implemented or applied through different specific implementation manners. The details in this specification can also be applied based on different viewpoints, and various modifications or changes can be made without departing from the overall design concept of the invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. The following exemplary embodiments of this invention can be implemented in many different forms and should not be construed as being limited only to the specific embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of this invention thorough and complete, and to fully convey the technical solutions of these exemplary specific embodiments to those skilled in the art.

[0028] The First Embodiment;

[0029] ReferenceFigure 1 As shown in the figure, the present invention provides a method for calibrating the stroke of a PTS sensor, including the following steps:

[0030] S1. Determine whether the calibration conditions are met. If not, exit the calibration.

[0031] Exemplarily, send a host computer control command to enter the EOL (end of line, product offline detection) mode, and clear the calibration fitting curve previously stored in the NVM (NVRAM Manager, non-volatile random access memory management).

[0032] Provide the UDS protocol (ISO14229, Unified Diagnostic Services) that complies with industry specifications.

[0033] Enter the EOL mode: Send the message 02 10 02 to switch to the programming session.

[0034] Send the message 02 3E 80 at a fixed period to ensure that the diagnostic device is online (Tester Present).

[0035] S2. Read the current position of the PTS sensor and record the data. If the PTS sensor data is outside the mechanical range of the ECU system, clear the calibration data and prompt calibration failure.

[0036] S3. Advance the pedal push rod by a fixed step length multiple times and then repeat step S2 until the feedback force of the pedal push rod is greater than the pedal force requirement of the ECU system. Read the current position value of the PTS sensor and record the data. If the data is outside the mechanical range of the ECU system, clear the calibration data and prompt calibration failure.

[0037] S4. Sort the recorded data in the order of recording and fill it into an array, and compare each element in the array. If the value of the previous array element is less than the value of the next array element, the calibration passes. Form a fitting curve from all the PTS sensor stroke calibration point data and then store it, for example, store it in the NVM.

[0038] S5. Power off and restart the ECU, advance the pedal push rod by a fixed step length again. If the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is within the error tolerance range, the PTS sensor position value is the data on the fitting curve closest to the current position value, and the calculated stroke value is:

[0039] Stroke value = position value - calibration zero point value. Record that the PTS calibration is successful and end the PTS calibration.

[0040] If the difference between the PTS sensor stroke value and the actual pedal push rod stroke value is outside the tolerance range, the calibration data is cleared and a calibration failure message is displayed. Furthermore, if the PTS sensor's current position value is less than the minimum value of the calibration data in the stored data, or greater than the maximum value of the calibration data in the stored data, the stroke value is recorded as 0, indicating an invalid stroke.

[0041] Among them, data of multiple PTS sensor stroke calibration points are calibrated, and the calibration points include: PTS sensor stroke zero point, PTS sensor stroke maximum value and multiple stroke intermediate measurement points, and the distance between two stroke intermediate measurement points is a fixed step length.

[0042] Optionally, the fixed step length range is 1 mm-50 mm.

[0043] Optionally, the above embodiment can be further improved. When implementing step S5, the pedal push rod is advanced by a fixed step length multiple times to determine whether the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is within the allowable error range.

[0044] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will also be understood that, unless expressly defined herein, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, rather than being interpreted in an idealized or overly formal sense.

[0045] The present invention has been described in detail above by way of specific embodiments and examples, but these do not constitute limitations of the present invention. Without departing from the principles of the present invention, those skilled in the art may make many variations and improvements, which should also be considered within the scope of protection of the present invention.

Claims

1. A method for calibrating the travel of a PTS sensor, characterized in that, It includes the following steps: S1. Determine whether the calibration conditions are met. If not, exit the calibration. S2. Read the current position of the PTS sensor and record the data. If the PTS sensor data is outside the mechanical range of the ECU system, clear the calibration data and prompt calibration failure. S3. Advance the pedal push rod by a fixed step length multiple times and then repeat step S2 until the feedback force of the pedal push rod is greater than the pedal force requirement of the ECU system. Read the current position value of the PTS sensor and record the data. If the data is outside the mechanical range of the ECU system, clear the calibration data and prompt calibration failure. S4. Sort the recorded data in the order of recording and fill it into an array for verification. Form a fitting curve from all the PTS sensor stroke calibration point data and then store it. S5. Power off and restart the ECU. Advance the pedal push rod by a fixed step length again. If the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is within the allowable error range, the PTS sensor position value is the data on the fitting curve closest to the current position value. Calculate the stroke value as follows: Stroke value = position value - calibration zero value. Record the success of this PTS calibration and end the PTS calibration. If the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is outside the allowable error range, clear the calibration data and prompt calibration failure.

2. The PTS sensor stroke calibration method according to claim 1, characterized in that: Calibrate the data of multiple PTS sensor stroke calibration points, and the calibration points include: the PTS sensor stroke zero point, the PTS sensor stroke maximum value, and multiple stroke intermediate measurement points. The distance between two stroke intermediate measurement points is a fixed step length.

3. The PTS sensor stroke calibration method according to claim 1, characterized in that: The range of the fixed step length is 1 mm - 50 mm.

4. The PTS sensor stroke calibration method according to claim 1, wherein, The calibration conditions include: Enter the EOL mode, clear the previous calibration data, and send periodic messages to ensure the device is online.

5. The PTS sensor stroke calibration method according to claim 1, characterized in that: Adopt the following method for verification: Compare each element in the array. If the value of the previous array element is less than the value of the next array element, the verification passes.

6. The PTS sensor stroke calibration method according to claim 1, characterized in that: When implementing step S5, advance the pedal push rod by a fixed step length multiple times and determine whether the difference between the PTS sensor stroke value and the actual stroke value of the pedal push rod is within the allowable error range.

7. The PTS sensor stroke calibration method according to claim 1, characterized in that: If the current position value of the PTS sensor is less than the minimum calibration data value in the stored data or greater than the maximum calibration data value in the stored data, the stroke value is recorded as 0, and this is an invalid stroke at this time.

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