Improved design method of rotation position sensor for automobile pedal

Abstract

The invention relates to an improved design method of a rotation position sensor for an automobile pedal, which comprises the following steps of: additionally arranging a rebound mechanism on the rotation position sensor to provide a reverse rebound force, and reducing an initial rotation error during installation; after a rotation position sensor is installed on an automobile pedal, on-site support-free calibration is carried out; and during field calibration, the configuration flexibility is improved by configuring the number of calibration points and the corresponding output voltage value. Compared with the prior art, the method has the advantages of being low in installation error requirement, low in production and manufacturing error requirement, very high in flexibility and the like.

Description

Technical Field

[0001] This invention relates to the field of automotive sensors, and in particular to an improved design method for a rotary position sensor for automotive pedals. Background Technology

[0002] Car pedals are the core control components for drivers to control vehicle power, braking and gear shifting. They mainly include the accelerator pedal, brake pedal and clutch pedal. The pedal opening is an important data for automatic and safe driving of automobiles, so it is necessary to accurately detect the pedal opening.

[0003] The current industry standard is to use a rotary position sensor to measure the rotation angle of the pedal in real time. However, this method is limited by vehicle signals, sensor installation space and installation method, as well as manufacturing precision, and has the following problems:

[0004] ① When the rotary position sensor is installed with the car pedal, concentricity deviation is unavoidable;

[0005] ② In order to make their products more competitive, car pedal manufacturers have to adopt methods to improve the manufacturing precision of pedals in order to ensure consistency between different pedals, which significantly increases production costs and time.

[0006] ③ For different vehicles, the rotation angle range of the car pedals is different, which means that the rotation position sensor needs to be designed with different angle measurement ranges to adapt to different angle ranges, resulting in poor applicability and flexibility.

[0007] Therefore, it is necessary to improve the structure, installation, and calibration methods of the current rotary position sensors used in automotive pedals to enhance measurement accuracy and calibration flexibility. Summary of the Invention

[0008] To address the technical problems in the background art, this invention provides an improved design method for a rotary position sensor for automotive pedals, offering a flexible configuration scheme encompassing selection, structural design, on-site installation, and calibration, including:

[0009] A spring-back mechanism is added to the rotary position sensor to provide reverse spring-back force, reducing the initial rotation error during installation;

[0010] After installing the rotary position sensor on the car pedal, perform on-site calibration without support.

[0011] During on-site calibration, the flexibility of configuration can be improved by configuring the number of calibration points and the corresponding output voltage values.

[0012] Furthermore, when selecting a rotary position sensor, the mechanical range of the rotary position sensor should be greater than the sum of the working range of the car pedal, the preload angle that generates the rebound force, and the angle margin, and the working range of the car pedal should be less than 90% of the mechanical range of the rotary position sensor.

[0013] Furthermore, the rebound mechanism includes a spring sleeved on the outside of the input shaft of the rotary position sensor, one end of the spring being fixed at the mounting position on the housing of the rotary position sensor, and the other end being mounted at the mounting position on the input shaft.

[0014] Furthermore, before installing the rotary position sensor onto the rotating shaft of the car pedal, the spring is pre-tightened to provide a restoring force, ensuring a tight contact between the input shaft and the rotating shaft of the car pedal, thus reducing the initial rotational error during installation.

[0015] Furthermore, on-site calibration without support can be performed using one calibration point plus a given slope, two calibration points using linear interpolation, or three or more calibration points using multi-segment linear interpolation.

[0016] Furthermore, the linear interpolation method using two calibration points specifically includes the following steps:

[0017] 1) When the input shaft of the rotary position sensor is installed on the rotary shaft of the car pedal and pressed down by the spring return force, this position is taken as the initial position when the car pedal is not rotating. A calibration is performed at this initial position, and the angle θ of the rotary position sensor corresponding to the initial position is recorded. 初始 And for that angle θ 初始 Configure the corresponding output voltage value V 初始 ;

[0018] 2) When the car pedal can no longer be rotated, this point is taken as the final position where the car pedal has been rotated to its full extent. A calibration is then performed at this final position, and the angle θ of the rotation position sensor corresponding to this final position is recorded. 终止 And for that angle θ 终止 Configure the corresponding output voltage value V 终止 ;

[0019] 3) Based on the output voltage values ​​corresponding to the initial and final positions, perform linear interpolation calculations to complete the position calibration between the initial and final positions. Then:

[0020]

[0021] Where k is the slope, V is the output voltage value corresponding to the current angle θ, and O is the opening degree of the car pedal.

[0022] Furthermore, after completing the linear interpolation at the two calibration points, the following steps are also included:

[0023] 4) Configure the output voltage values ​​of the rotary position sensor for angles other than the actual working range of the car pedal to prevent output voltage jumps. Specifically, configure the rotary position sensor from the minimum mechanical angle to angle θ. 初始 The voltage configuration corresponding to the range is V 初始 The rotational position sensor is moved from angle θ 终止 The voltage configuration corresponding to the maximum mechanical angle range is V. 终止 .

[0024] Furthermore, when calibrating without support on-site, if the rotary position sensor adopts a redundant design, the slopes of its two channels will be the same or opposite numbers.

[0025] Furthermore, when there is no on-site calibration, if the car pedal needs to achieve a combination of light and heavy pedaling, a piecewise linear interpolation method is adopted with three calibration points. The initial position, intermediate position, and termination position are selected, and the output voltage value is configured so that the absolute value of the slope corresponding to the first section is less than that of the second section.

[0026] Furthermore, the host computer connects to the rotary position sensor via a programmer for on-site calibration. The host computer is equipped with rotary position sensor calibration software, including:

[0027] Serial port connection module: used to select the communication port to achieve communication connection between the host computer and the encoder;

[0028] Product control module: used to select the type of rotary position sensor and set the slope;

[0029] Product calibration module: used to configure the output voltage value and clamping voltage at the calibration position;

[0030] Product inspection module: Used to perform actual testing at each test point after calibration, to help determine whether the automotive pedal product with the currently installed rotary position sensor is qualified.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] I. The present invention applies a rebound force in advance to the rebound mechanism of the rotary position sensor. When the rotary position sensor is installed on the rotating shaft of the car pedal, the rebound force can make the two close together and press tightly, thereby reducing the installation error requirements of the rotary position sensor.

[0033] Second, the present invention adopts the scheme of first installing and then calibrating at two points without support. Since the two points selected for calibration are the initial position and the end position of the working range of the car pedal, it can adapt to car pedal products with different manufacturing errors, thereby reducing the requirements for the manufacturing error of the car pedal.

[0034] Third, it is flexible in configuration. The rotary position sensor, in conjunction with the encoder, can achieve voltage calibration at any angle within the mechanical range. It is highly flexible and eliminates the need to design multiple rotary position sensors with different mechanical ranges for different working ranges of car pedals. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0036] Figure 2 A schematic diagram of the two-point calibration process for a rotary position sensor;

[0037] Figure 3 This is a schematic diagram of the calibration interface for rotary position sensor calibration software. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0039] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0041] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0042] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0044] Example

[0045] like Figure 1 As shown, this invention provides an improved design method for a rotary position sensor for automotive pedals, offering an overall solution for adapting a rotary position sensor to automotive pedals. This improves the tolerance of automotive pedals with rotary position sensors to installation errors, reduces the manufacturing precision requirements of automotive pedals, and enhances the adaptability and flexibility of calibration. The design method mainly involves improved design schemes for the structure of the rotary position sensor, the installation method of the rotary position sensor on the automotive pedal, and the on-site calibration method, as described in detail below:

[0046] 1. Improve the structure of the rotary position sensor to increase the tolerance for installation errors.

[0047] In this example, a rebound mechanism is added to the rotary position sensor. Specifically, a spring is fitted around the outside of the input shaft of the rotary position sensor. One end of the spring is fixed to the mounting position on the housing of the rotary position sensor, and the other end is connected to the mounting position on the outside of the input shaft. The spring provides the rebound force of the input shaft. In addition, two mechanical limit blocks are provided circumferentially at the mounting position of the input shaft on the housing of the rotary position sensor to limit the rotation range of the input shaft, i.e., the mechanical range of the rotary position sensor. In this example, the mechanical range design of the rotary position sensor takes into account both angle requirements and output sensitivity requirements. The angle requirements need to cover the actual working range of the car pedal, the angle of the spring preload rebound force (generally not exceeding 10% of the mechanical range), and the safety angle margin. The measurement resolution requirement is that the output voltage / current range corresponding to the actual working range of the car pedal should be as large as possible.

[0048] Because a spring-loaded mechanism is added to the rotary position sensor, the input shaft of the rotary position sensor is pre-rotated by a certain angle before being installed onto the rotating shaft of the car pedal. During installation, the input shaft of the rotary position sensor has a reverse spring-loaded force under the action of the spring preload. This spring-loaded force ensures that the input shaft is always in tight contact with the rotating shaft of the car pedal, eliminating the rotational gap between the two, reducing the initial rotational error during installation, and thus improving the tolerance for installation errors.

[0049] 2. The rotary position sensor is installed on the car pedal on-site and then calibrated, which reduces the requirements for the production consistency of the car pedal.

[0050] In this invention, after the rotational position sensor is installed on the car pedal, a two-point unsupported calibration is performed on-site. The specific process is as follows:

[0051] 1) When the input shaft of the rotary position sensor is installed on the rotary shaft of the car pedal, under the pressure of the spring return force, this position is taken as the initial position when the car pedal is not rotating. A calibration is performed at this initial position, and the angle θ of the rotary position sensor corresponding to the initial position is recorded. 初始 And for that angle θ 初始 Configure the corresponding output voltage value V 初始 (The voltage value output by the rotary position sensor can be used as a signal to communicate with the vehicle controller to characterize the opening of the vehicle pedals);

[0052] 2) When the car pedal rotates to the point where it can no longer rotate under continuous external force, this point is taken as the final position where the car pedal has rotated to its full extent. A calibration is then performed at this final position, and the angle θ of the rotation position sensor corresponding to this final position is recorded. 终止 And for that angle θ 终止 Configure the corresponding output voltage value V 终止 ;

[0053] 3) Based on the output voltage values ​​corresponding to the initial and final positions, perform linear interpolation calculations to complete the calibration of the position between the initial and final positions (including the position range between the initial and final positions, i.e., the actual working range of the car pedal), then:

[0054]

[0055] Where k is the slope, V is the output voltage value corresponding to the current angle θ, and O is the opening degree of the car pedal (i.e., voltage percentage).

[0056] Furthermore, V 初始 With V 终止 The values ​​of V are all within the output voltage range of the current rotary position sensor. For example, if the output voltage range of the current rotary position sensor is 0-5V, then V 初始 With V 终止 The values ​​can be 0.5V and 4.5V respectively. In order to maximize the detection sensitivity, when selecting a sensor (before production and installation), the actual working range of the car pedal should be less than 90% of the mechanical range of the rotary position sensor.

[0057] 4) After completing the two-point calibration of the car pedal, it is also necessary to configure the output voltage values ​​of the rotary position sensor for angles other than the actual working range of the car pedal. Taking the mechanical range of the rotary position sensor as 0-100°, the actual working range of the car pedal as 0-80°, the spring return force pre-rotation angle as 10°, and the sum of the current production and assembly errors of the car pedal as 1.1° as an example, the initial angle (0°) of the car pedal corresponds to an angle of 11.1° for the rotary position sensor, and the corresponding output voltage value is configured as 0.5°. The termination angle (+ The angle of the rotary position sensor corresponding to 80° is 91.1°, and the corresponding output voltage value is configured to be 4.5° with a positive slope. In order to prevent the voltage output from jumping, the output voltage value of the rotary position sensor corresponding to 0°-11.1° is set to 0.5V, and the output voltage value corresponding to 91.1°-100° is set to 4.5V. Similarly, for the case with a negative slope, the output voltage value of the rotary position sensor corresponding to 0°-11.1° is set to 4.5V, and the output voltage value corresponding to 91.1°-100° is set to 0.5V.

[0058] Preferably, in order to make full use of the part of the rotary position sensor with better linearity, the 50% opening position of the car pedal should be located at the center of the mechanical range of the rotary position sensor.

[0059] This invention calibrates the vehicle pedal once when it is in its initial position and again when it rotates to its final position. After linear interpolation, the actual working range of the rotational position sensor within the vehicle pedal is calibrated, without the need for other high-precision equipment. Considering that the precision of vehicle pedals decreases during production and manufacturing, leading to reduced consistency between different pedal products, this invention adopts a post-installation calibration method. This is equivalent to tailoring each vehicle pedal product to a specific requirement, thereby reducing the impact of inconsistency. It allows for reduced precision in the production and manufacturing of vehicle pedal products, resulting in lower costs and greater long-term competitiveness.

[0060] It should be noted that the number of calibration points and the sign of the slope used in the unsupported field calibration of this invention can be adaptively configured according to actual testing requirements, improving the design flexibility of this invention. Specifically, this includes:

[0061] (1) One calibration point + given slope: suitable for high-precision and high-linearity automotive pedal products;

[0062] (2) Two calibration points (initial position and end position): applicable to two-point linear interpolation calibration (fixed slope) for ordinary automotive pedal products;

[0063] (3) Three or more calibration points (initial position, ending position and several intermediate calibration points): This is suitable for situations where the intermediate calibration position is more sensitive. Piecewise linear interpolation is used for calibration to improve the linearity of the measurement.

[0064] Additionally, if the car pedal needs to achieve a combination of light and heavy pedaling, such as braking with 90% light and slow braking at the beginning and 10% heavy and sudden braking at the end, three calibration points can be selected: the initial position (0% opening), the middle position (90% opening), and the final position (100% opening). Piecewise linear interpolation can be used for calibration, but by configuring different output voltage values, the slope (or the absolute value of the slope) corresponding to the beginning is much lower than that of the end. This way, the braking requirement of light pedaling at the beginning and heavy pedaling at the end can be achieved.

[0065] Positive / Negative Slope: Applicable to cases of redundant rotary position sensor channels. The two channels of the rotary position sensor can be respectively assigned positive / negative slopes, and these positive / negative slopes are opposites of each other. In addition, when the rotary position sensor channels are redundant, the slopes of the two channels can also be configured to be the same.

[0066] 3. For example Figure 2 As shown, in order to facilitate automatic on-site calibration, this invention also realizes the calibration of automotive pedal products through an encoder (an existing open-source programmable data adapter) and a host computer. The host computer runs rotary position sensor calibration software, which is connected to the encoder through a serial port. The encoder is connected to the output interface of the rotary position sensor. The output port of the rotary position sensor can be used as both the output interface for detection data and the programming interface for calibration.

[0067] like Figure 3 As shown in the figure, the calibration interface of the rotary position sensor calibration software of the host computer is displayed. The rotary position sensor calibration software includes a serial port connection module, a product control module, a product calibration module, and a product inspection module. The functions of each module are described below.

[0068] (1) The serial port connection module is used to select the communication port to realize the communication connection between the host computer and the encoder;

[0069] (2) The product type selection unit of the product control module is used to select the type of rotary position sensor, which is applicable to single-channel rotary position sensor (non-redundant) and dual-channel rotary position sensor (redundant). The parameter consistency selection unit is used to ensure that the slope of the output voltage value of the lower channel of the dual-channel rotary position sensor is the same or opposite to each other.

[0070] (3) The product calibration module is used to configure the output voltage values ​​of the initial position (point A) and the final position (point B) during two-point calibration. It can also set the maximum and minimum percentage of the clamping voltage (in this example, 10% of the sensor's maximum operating voltage of 5V is 0.5V, and 90% is 4.5V). In addition, it can also be adapted to single-point and three-point or more calibrations.

[0071] (4) The product inspection module is used to perform actual testing at various angle detection points within the actual working range of the car pedal after calibration, output and display the current channel voltage value and the corresponding voltage ratio (i.e., opening degree) in real time, and assist in judging whether the car pedal product with the currently installed rotation position sensor is qualified.

[0072] In this invention, the rotary position sensor is used in conjunction with a programmable programmer. By setting the corresponding voltage value, it can be adapted to the angle measurement of the working range of different car pedal models, eliminating the need to design multiple rotary position sensors with different mechanical ranges to adapt to different working ranges.

[0073] In addition, the present invention has high calibration flexibility. It uses a two-point calibration method to determine the output curve of the rotary position sensor. During on-site calibration, the output voltage value of the calibration position can be freely input within the mechanical range, making the calibration more flexible. In addition to two-point calibration, it can also be extended to multi-point calibration or slope calibration, further expanding the calibration flexibility. At the same time, multi-point calibration can also improve the measurement linearity.

[0074] In summary, this invention provides an improved design method for a rotary position sensor for automotive pedals, offering a practical solution for a highly flexible, linear, and precise rotary position sensor for automotive pedals, encompassing structural design and field calibration. This solution addresses the challenges of low manufacturing consistency, large installation position errors, and poor calibration flexibility in automotive pedal products, achieving flexible adjustment of calibration voltage, high tolerance for inconsistencies and installation errors. It demonstrates excellent practical applicability and can also address the issue of reducing the production cost of automotive pedal products.

[0075] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. An improved design method for a rotary position sensor for automotive pedals, characterized in that, include: A spring-back mechanism is added to the rotary position sensor to provide reverse spring-back force, reducing the initial rotation error during installation; After installing the rotary position sensor on the car pedal, perform on-site calibration without support. During on-site calibration, the flexibility of configuration can be improved by configuring the number of calibration points and the corresponding output voltage values.

2. The improved design method of a rotary position sensor for automotive pedals according to claim 1, characterized in that, When selecting a rotary position sensor, the mechanical range of the rotary position sensor should be greater than the sum of the working range of the car pedal, the preload angle that generates the rebound force, and the angle margin, and the working range of the car pedal should be less than 90% of the mechanical range of the rotary position sensor.

3. The improved design method of a rotary position sensor for automotive pedals according to claim 1, characterized in that, The rebound mechanism includes a spring sleeved on the outside of the input shaft of the rotary position sensor. One end of the spring is fixed to the mounting position on the housing of the rotary position sensor, and the other end is mounted on the mounting position on the input shaft.

4. The improved design method for a rotary position sensor for automotive pedals according to claim 2, characterized in that, Before installing the rotary position sensor onto the rotating shaft of the car pedal, the spring is preloaded to provide a rebound force, ensuring a tight contact between the input shaft and the rotating shaft of the car pedal, thus reducing the initial rotational error during installation.

5. The improved design method of a rotary position sensor for automotive pedals according to claim 1, characterized in that, On-site calibration without support can be performed using one calibration point plus a given slope, two calibration points using linear interpolation, or three or more calibration points using multi-segment linear interpolation.

6. An improved design method for a rotary position sensor for automotive pedals according to claim 5, characterized in that, The linear interpolation method using two calibration points specifically includes the following steps: 1) When the input shaft of the rotary position sensor is installed on the rotary shaft of the car pedal and pressed down by the spring return force, this position is taken as the initial position when the car pedal is not rotating. A calibration is performed at this initial position, and the angle θ of the rotary position sensor corresponding to the initial position is recorded. 初始 And for that angle θ 初始 Configure the corresponding output voltage value V 初始 ; 2) When the car pedal can no longer be rotated, this point is taken as the final position where the car pedal has been rotated to its full extent. A calibration is then performed at this final position, and the angle θ of the rotation position sensor corresponding to this final position is recorded. 终止 And for that angle θ 终止 Configure the corresponding output voltage value V 终止 ; 3) Based on the output voltage values ​​corresponding to the initial and final positions, perform linear interpolation calculations to complete the position calibration between the initial and final positions. Then: Where k is the slope, V is the output voltage value corresponding to the current angle θ, and O is the opening degree of the car pedal.

7. An improved design method for a rotary position sensor for automotive pedals according to claim 6, characterized in that, After completing the linear interpolation at the two calibration points, the following steps are also included: 4) Configure the output voltage values ​​of the rotary position sensor for angles other than the actual working range of the car pedal to prevent output voltage jumps. Specifically, configure the rotary position sensor from the minimum mechanical angle to angle θ. 初始 The voltage configuration corresponding to the range is V 初始 The rotational position sensor is moved from angle θ 终止 The voltage configuration corresponding to the maximum mechanical angle range is V. 终止 .

8. An improved design method for a rotary position sensor for automotive pedals according to claim 5, characterized in that, When calibrating without support on site, if the rotary position sensor adopts a redundant design, the slopes of its two channels will be the same or opposite numbers.

9. An improved design method for a rotary position sensor for automotive pedals according to claim 5, characterized in that, When there is no support for calibration on site, if the car pedal needs to achieve a combination of light and heavy pedaling, a piecewise linear interpolation method is used with three calibration points. The initial position, intermediate position and termination position are selected, and the output voltage value is configured so that the absolute value of the slope corresponding to the first part is less than that of the second part.

10. An improved design method for a rotary position sensor for automotive pedals according to claim 1, characterized in that, The host computer connects to the rotary position sensor via a programmer for on-site calibration. The host computer is equipped with rotary position sensor calibration software, including: Serial port connection module: used to select the communication port to achieve communication connection between the host computer and the encoder; Product control module: used to select the type of rotary position sensor and set the slope; Product calibration module: used to configure the output voltage value and clamping voltage at the calibration position; Product inspection module: Used to perform actual testing at each test point after calibration, to help determine whether the automotive pedal product with the currently installed rotary position sensor is qualified.

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