CN107097643B - A Non-contact Accelerator Pedal Sensor System Based on Hall Effect - Google Patents

Abstract

The invention discloses a non-contact accelerator pedal sensor system based on Hall effect, which comprises a support fixed on a vehicle, a pedal rod hinged on the support through a pedal hinge shaft, a return spring connected with the pedal rod and the support and used for returning the pedal rod, one side of the support is provided with a pedal sensor based on a Hall effect, the pedal sensor is in driving connection with a pedal rod and converts the swing of the pedal rod into an electric signal to be output to an engine manager, so that the engine manager senses the operation of a driver on an accelerator in real time, and the power output is changed. The invention avoids the abrasion problem of the traditional accelerator pedal sensor, and greatly prolongs the service life while improving the precision.

Description

A Non-contact Accelerator Pedal Sensor System Based on Hall Effect

technical field

The invention belongs to the field of automobile control, and in particular relates to a Hall effect-based non-contact gas pedal sensor system.

Background technique

With the continuous popularization of automobiles in daily life, its power, safety and comfort have received more and more attention. These performance enhancements depend on the development of automotive electronic control systems. The accelerator pedal sensor is an important part of the electronic control system of the vehicle, and its performance directly affects the reliability and stability of the entire electronic control system of the vehicle.

The traditional accelerator pedal sensor uses the potentiometer principle, and uses thick film resistors or conductive plastics as the resistor matrix. When the driver steps on the gas pedal, the electric brush is driven to move, changing its relative position with the resistance matrix. By detecting the voltage change to judge the relative position of the brush, and finally determine the rotation angle of the accelerator pedal.

However, the working environment of the car is relatively harsh, and the accelerator pedal sensor needs to maintain good stability under high temperature and vibration conditions. The traditional contact resistance sensor brush and resistance substrate are easy to wear, which seriously affects the output characteristics and service life of the sensor. Moreover, the signal current allowed to pass through the resistor substrate is generally relatively small, and specific electrical connection components need to be developed in the actual application process, which further increases the development cost.

Contents of the invention

The technical problem to be solved by the invention is: the traditional contact pedal sensor has poor precision and short service life.

In order to solve the above technical problems, the present invention adopts the following technical solutions to realize:

A non-contact accelerator pedal sensor system based on the Hall effect, including a support fixed on the vehicle, a pedal rod hinged on the support through a pedal hinge shaft, connected to the pedal rod and a support for the pedal rod The return spring for returning, one side of the support is provided with a pedal sensor based on the Hall effect, the pedal sensor is connected to the pedal rod for driving and converts the swing of the pedal rod into an electrical signal and outputs it to the engine manager, thereby Make the engine manager sense the driver's operation on the accelerator in real time, and change the power output.

Further, the pedal sensor includes: a sleeve, a bolt, a transmission link, a gasket, a shell, a cylindrical magnet, a circular circuit board, and an end cover, and the center of the gasket is provided with a flat hole in the center of the gasket, The edge is eccentrically provided with a gasket eccentric hole, one end of the bolt is movably connected with the gasket eccentric hole, and the sleeve is rotatably set on the bolt and passes through the arc-shaped hole on one side of the support and the end of the pedal rod. The fork is matched; the transmission connecting rod is fixedly connected to one side of the shell through the central flat hole of the gasket, and the cylindrical magnet is centered and fixed on the other side of the shell to convert the actual angle signal into a magnetic signal; The circular circuit board is fixed in the end cover and is opposite to the cylindrical magnet for converting the magnetic signal into an electric signal and filtering the electric signal; the end cover is fixed on the support by fastening screws On one side, the wiring harness of the circular circuit board is led out through the end cover and connected to the engine manager.

Further, the transmission connecting rod sequentially includes a cylindrical part, a positioning shoulder, and a driving part. The cross-sectional shape of the driving part matches the shape of the flat hole in the center of the gasket. Rod positioning hole, the cylindrical part is rotatably inserted into the positioning hole of the transmission link and axially positioned by the positioning shoulder, and a housing connecting hole whose shape matches the driving part is centrally provided on one side of the housing.

Further, the circular circuit board includes an angular position detection module and a signal filtering module, and the angular position detection module adopts MLX90360 three-axis Hall effect chip.

Further, the cylindrical magnet adopts N35SH NdFeB cylindrical magnet with a diameter ≥ 4mm.

Furthermore, when the cylindrical magnet rotates around its center, the eccentricity relative to the center of the MLX90360 three-axis Hall effect chip is less than 0.2mm, which reduces the problem of the accuracy of the accelerator pedal sensor caused by the error of the mechanical structure.

Further, the distance between the front end surface of the cylindrical magnet and the sensing part of the MLX90360 three-axis Hall effect chip is 2 mm ± 0.01 mm, which reduces the problem of the decrease in accuracy of the accelerator pedal sensor caused by the error of the mechanical structure.

Further, the center position error between the cylindrical magnet and the sensing part of the MLX90360 three-axis Hall effect chip is less than 0.1mm, which reduces the problem of the decrease in the accuracy of the accelerator pedal sensor caused by the error of the mechanical structure.

Further, the center parallelism error between the cylindrical magnet and the sensing part of the MLX90360 three-axis Hall effect chip is less than 0.1mm, which reduces the problem of the decrease in the accuracy of the accelerator pedal sensor caused by the error of the mechanical structure.

Further, the material of the shell is PA66 A218V20 engineering plastic, which reduces the electromagnetic interference of the pedal sensor during use.

The present invention introduces the MLX90360 three-axis Hall effect position sensor on the basis of the traditional accelerator pedal sensor. It fundamentally solves the problems of easy wear, low precision and short service life of the traditional contact accelerator pedal sensor. At the same time, it also overcomes the shortcomings of complex layout and numerous wiring harnesses existing in the capacitive sensor. And it has optimized the error caused by the unreasonable mechanical structure of the general non-contact Hall effect sensor. The accuracy can be increased to 0.4°, and the independent linearity can reach 1.05%, with high repeatability. The invention meets the requirements of the automobile pedal sensor and can provide accurate and reliable pedal stroke measurement for the automobile engine manager in real time.

Description of drawings

Fig. 1 is a three-dimensional schematic diagram of an embodiment of the present invention.

Fig. 2 is a schematic diagram of an exploded structure of an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a transmission link according to an embodiment of the present invention.

Fig. 4 is a schematic diagram of the gasket structure of an embodiment of the present invention.

Fig. 5 is a schematic diagram of the support structure of an embodiment of the present invention.

Fig. 6 is a schematic diagram of the shell structure of an embodiment of the present invention.

Fig. 7 is a schematic structural diagram of a circular circuit board according to an embodiment of the present invention.

Fig. 8 is a schematic diagram of the control flow of the embodiment of the present invention.

Fig. 9 is a schematic circuit diagram of an embodiment of the present invention.

Fig. 10 is a schematic diagram of the relative positions of the cylindrical magnet and the MLX90360 three-axis Hall effect chip under the initial conditions of an embodiment of the present invention.

In the figure: 1-pedal lever, 2-support, 21-arc hole, 22-positioning hole of transmission link, 23-hinge hole, 24-screw hole, 25-spring positioning groove, 3-sleeve, 4- Bolt, 5-transmission connecting rod, 51-cylindrical part, 52-locating shoulder, 53-driving part, 6-gasket, 61-gasket eccentric hole, 62-gasket center hole, 7-shell, 71-shell Connection hole, 8-cylindrical magnet, 9-circular circuit board, 91-angle position detection module, 10-end cover, 11-fastening screw; 12-pedal hinge shaft, 13-return spring.

Detailed ways

In order to make the technical solutions and advantages of the present invention more prominent, the present invention will now be described clearly and completely in conjunction with the accompanying drawings. Based on the described embodiments of the present invention, other examples obtained by persons of ordinary skill in the art without making creative efforts should also belong to the protection scope of the present invention.

As shown in Figures 1 to 7, a non-contact accelerator pedal sensor system based on the Hall effect includes a support 2 fixed on the vehicle, a pedal rod hinged on the support 2 through a pedal hinge shaft 12 1. A return spring 13 connected to the pedal rod 1 and the support 2 for the return of the pedal rod 1. The support 2 is provided with a hinge hole 23 and a spring positioning groove 25. One side of the support 2 is provided with a The pedal sensor of the Hall effect, the pedal sensor is connected with the pedal lever 1 and converts the swing of the pedal lever 1 into an electrical signal and outputs it to the engine manager, so that the engine manager can sense the driver's operation on the accelerator in real time and change PTO.

Specifically, the pedal sensor includes: a sleeve 3, a bolt 4, a transmission connecting rod 5, a gasket 6, a housing 7, a cylindrical magnet 8, a circular circuit board 9, an end cover 10, and the gasket 6. The center of the gasket is provided with a central flat hole 62, and the edge is eccentrically provided with a gasket eccentric hole 61 (see Figure 4). One end of the bolt 4 is flexibly connected to the gasket eccentric hole 61. The arc-shaped hole 21 on the bolt 4 and through the side of the support 2 is matched with the fork at the tail end of the pedal rod 1; the transmission connecting rod 5 is fixedly connected to the side of the housing 7 through the flat hole 62 in the center of the gasket , the cylindrical magnet 8 is centrally fixed on the other side of the housing 7 for converting the actual angle signal into a magnetic signal; the circular circuit board 9 is fixed in the end cover 10 and is opposite to the cylindrical magnet 8 , used to convert the magnetic signal into an electrical signal, and filter the electrical signal. The power supply is a 6V DC rechargeable power supply; the end cover 10 is fixed on one side of the support 2 by fastening screws, and the circular circuit The wiring harness of the board 9 is connected with the engine manager after being led out through the end cover 10 .

As shown in FIG. 3 , the transmission connecting rod 5 sequentially includes a cylindrical portion 51, a positioning shoulder 52, and a driving portion 53. The cross-sectional shape of the driving portion 53 matches the shape of the flat hole 62 in the center of the washer. One side of the support 2 is provided with a transmission connecting rod positioning hole 22, the cylindrical part 51 is rotatably inserted into the transmission connecting rod positioning hole 22 and axially positioned by the positioning shoulder 52, and one side of the housing 7 is centered There is a housing connecting hole 71 whose shape matches the driving part 53 .

As shown in FIG. 7 , the circular circuit board 9 includes an angular position detection module 91 and a signal filtering module, and the angular position detection module adopts a MLX90360 three-axis Hall effect chip.

The cylindrical magnet 8 of this embodiment is a N35SH NdFeB cylindrical magnet with a size of D6H1. If an alternative solution is required, the magnetic induction intensity excited in the space shall not be higher than 70mT, and shall not be lower than 20mT.

Because the accuracy of the mechanical assembly will have a considerable impact on the measurement of the overall angle, especially the position of the magnet during the rotation process plays a decisive role in the accuracy of the entire sensor. Therefore, the cylinder of this embodiment When the shaped magnet 8 rotates around its center, the eccentricity relative to the center of the MLX90360 three-axis Hall effect chip is <0.2mm; the distance between the front end of the cylindrical magnet 8 and the sensing part of the MLX90360 three-axis Hall effect chip is 2mm±0.01 mm; the central position error of the cylindrical magnet 8 and the sensing part of the MLX90360 three-axis Hall effect chip <0.1mm; the center parallelism error of the cylindrical magnet 8 and the sensing part of the MLX90360 three-axis Hall effect chip <0.1 mm, so as to reduce the problem of the accuracy of the accelerator pedal sensor caused by the error of the mechanical structure.

At the same time, the material of the shell 7 is PA66 A218V20 engineering plastic to reduce the electromagnetic interference of the pedal sensor during use.

Specific principle: During driving, when the driver depresses the accelerator pedal, the pedal rod 1 will rotate around the pedal hinge shaft 12 connected to the support 2, and the fork at the tail end of the pedal rod 1 will rotate through the sleeve 3 And the bolt 4 is transmitted to the gasket 6, and the rotation of the gasket 6 will make the transmission connecting rod 5 drive the cylindrical magnet 8 embedded in the shell 7 to rotate, and the circular circuit board 9 and the end cover 10 are fixedly connected. The screw 11 is fixed on one side of the support 2 . The cylindrical magnet 8 is facing the surface of the MLX90360 three-axis Hall effect chip. When the cylindrical magnet 8 rotates, the MLX90360 three-axis Hall effect chip on the circuit board parallel to it will detect the change of the magnetic induction intensity and convert it into The electrical signal, the electrical signal shown is filtered and output to the engine manager in the form of analog, so that the engine manager can sense the driver's operation on the accelerator in real time and change the power output.

Fig. 8 is a schematic workflow diagram of an embodiment of the present invention, including steps:

S11: the accelerator pedal is depressed;

S12: drive the cylindrical magnet 8 to rotate;

S13: Angle position measurement module 91 senses angle change;

S14: Output in the form of analog quantity.

Wherein, step S13 specifically includes: the magnetism collecting material of the MLX90360 three-axis Hall effect chip captures the magnetic field change parallel to the chip surface, and generates two components in two perpendicular directions proportional to the magnetic field intensity, and then two pairs of These two signals are detected by conventional planar Hall elements perpendicular to each other and parallel to the chip surface.

Step S14 specifically includes: encoding the two signals obtained in step S13 into two sine and cosine signals with a phase difference of 90 degrees, and finally amplifying, sampling and converting them into digital signals, and the two digital signals will calculate the angle through the arctangent function value, the digital signal representing the current angle value is then passed through a digital-to-analog converter to obtain an analog output.

Figure 9 is the circuit diagram of this embodiment, because the MLX90360 three-axis Hall effect chip has a high degree of integration, it only needs to simply filter the analog signal in the periphery.

FIG. 10 shows the relative positional relationship between the cylindrical magnet 8 and the MLX90360 three-axis Hall effect chip under the initial condition of the present embodiment and the accelerator pedal sensor is at electrical zero degree.

As a preferred solution, the MLX90360 three-axis Hall effect chip is calibrated using the 16-point calibration method of the PTC-04 programming tool provided by Melexis. The detailed operation is as follows: After connecting the MLX90360 chip and PTC-04, the PTC -04 Connect to the computer and select the corresponding chip model. First set the output mode, output angle mapping field, clamp low level ratio, clamp high level ratio, start angle, and filter method. Then the gain is automatically set by the DAC. Finally, choose 16-point programming.

During driving, when the driver depresses the accelerator pedal, the pedal rod will drive the cylindrical magnet at the front end of the sensor shaft to rotate. A chip on a circuit board parallel to the front face detects changes in magnetic induction and converts them into electrical signals. After filtering, it is output to the engine manager in the form of analog quantity. So that the engine manager senses the driver's operation on the accelerator in real time and changes the power output.

The above-mentioned embodiments are only used to illustrate the features of the present invention, and should not limit other implementations accordingly. For those skilled in the art, various modifications can be made based on the idea of the present invention. It is impossible and unnecessary to list them all here, and any non-creative changes made within the spirit and principle of the present invention shall be included within the protection scope of the patent claims of the present invention.

Claims (9)

1. The utility model provides a non-contact accelerator pedal sensor system based on hall effect, includes support (2) fixed on the car, articulates through footboard hinge (12) pedal pole (1) on support (2), connects return spring (13) that are used for pedal pole (1) return in pedal pole (1) and support (2), its characterized in that:

one side of the support (2) is provided with a pedal sensor based on a Hall effect, the pedal sensor is in driving connection with the pedal rod (1) and converts swing of the pedal rod (1) into an electric signal to be output to an engine manager, so that the engine manager senses the operation of a driver on an accelerator in real time and changes the power output;

the pedal sensor includes:

the novel pedal rod comprises a sleeve (3), a bolt (4), a transmission connecting rod (5), a gasket (6), a shell (7), a cylindrical magnet (8), a circular circuit board (9) and an end cover (10), wherein a gasket central flat hole (62) is formed in the center of the gasket (6), a gasket eccentric hole (61) is eccentrically formed in the edge of the gasket, one end of the bolt (4) is movably connected with the gasket eccentric hole (61), and the sleeve (3) is rotatably sleeved on the bolt (4) and penetrates through an arc-shaped hole (21) on one side of a support (2) to be matched with a fork opening at the tail end of the pedal rod (1); the transmission connecting rod (5) passes through a flat hole (62) in the center of the gasket and is fixedly connected with one side of the shell (7), the cylindrical magnet (8) is centrally fixed on the other side of the shell (7), when an accelerator pedal is depressed, the pedal rod (1) rotates around a pedal hinge shaft (12) connected with the support (2), a fork opening at the tail end of the pedal rod (1) transmits a rotating angle to the gasket (6) through the sleeve (3) and the bolt (4), and the rotation of the gasket (6) enables the transmission connecting rod (5) to drive the cylindrical magnet (8) embedded in the shell (7) to rotate; the circular circuit board (9) is fixed in the end cover (10) and is opposite to the cylindrical magnet (8) and is used for converting a magnetic signal into an electric signal and filtering the electric signal; the end cover (10) is fixed on one side of the support (2) through a fastening screw (11), and the wire harness of the circular circuit board (9) is led out through the end cover (10) and then connected with the engine manager.

2. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the transmission connecting rod (5) sequentially comprises a cylindrical part (51), a positioning shaft shoulder (52) and a driving part (53), the cross section shape of the driving part (53) is matched with the shape of a flat hole (62) in the center of the gasket, one side of the support (2) is provided with a transmission connecting rod positioning hole (22), the cylindrical part (51) is rotationally inserted into the transmission connecting rod positioning hole (22) and is axially positioned by the positioning shaft shoulder (52), and one side of the shell (7) is centrally provided with a shell connecting hole (71) with the shape matched with the driving part (53).

3. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the circular circuit board (9) comprises an angular position detection module and a signal filtering module, wherein the angular position detection module adopts an MLX90360 three-axis Hall effect chip.

4. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the cylindrical magnet (8) is an N35SH neodymium-iron-boron cylindrical magnet, and the diameter is more than or equal to 4mm.

5. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the eccentricity of the cylindrical magnet (8) rotating about its centre is <0.2mm relative to the centre of the MLX90360 three-axis hall effect chip.

6. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the distance between the front end face of the cylindrical magnet (8) and the sensing part of the MLX90360 three-axis Hall effect chip is 2mm plus or minus 0.01mm.

7. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the error of the center position of the sensing part of the cylindrical magnet (8) and the MLX90360 three-axis Hall effect chip is less than 0.1mm.

8. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the error of the central parallelism of the cylindrical magnet (8) and the sensing part of the MLX90360 three-axis Hall effect chip is less than 0.1mm.

9. A hall effect based non-contact accelerator pedal sensor system in accordance with claim 1, wherein: the shell (7) is made of PA 66A 218V20 engineering plastic.

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