P-gear switch acquisition circuit

Abstract

The invention relates to a P-gear switch acquisition circuit, and belongs to the technical field of automobiles. The circuit comprises a first power supply, a second power supply, an MCU, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a first filter capacitor, a second filter capacitor, a third filter capacitor, a fourth filter capacitor, a first MOS tube and a second MOS tube. The MCU comprises a first input port, a second input port, a third input port and a fourth input port; the fourth resistor is a first force sensitive resistor and is matched with the first P-gear key for use; one end of the first resistor is connected with the first input port, the other end of the first resistor is connected with a point a arranged between the first filter capacitor and the second resistor, and the other end of the first filter capacitor is grounded. According to the invention, unexpected activation of the CDP function caused by circuit failure, mechanical clamping stagnation or other reasons can be avoided.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular relates to a P gear switch acquisition circuit. Background Art

[0002] like Figure 3 As shown in the figure, the most commonly used P gear switch acquisition circuit currently includes two contacts, button1 and button2. When the P gear switch is pressed, button1 and button2 are pressed at the same time. At this time, P1 and P2 simultaneously acquire low levels. At this time, the MCU considers that the P gear switch is pressed and forwards the network signal of the P gear switch being pressed. The currently commonly used CDP function logic is: when the P gear switch long press time acquired by the MCU of the combination switch reaches 5 seconds (calibrable), a request CDP signal is issued, and the corresponding ESC will perform hydraulic braking and generate a deceleration of 0.6g, thereby safely parking the vehicle.

[0003] As mentioned above, the most widely used gear switch acquisition circuit can accurately collect the driver's pressing information through double electric contact on the basis of ensuring the diagnostic coverage that meets the functional safety requirements. However, this solution still has the following problems: when a person presses a key, there may be a situation where the key is pressed in an offset manner, resulting in one side of the contact collecting the key information, but the other side of the contact does not collect the key information; but when a certain contact acquisition circuit fails (such as button1 or button2 is short-circuited to the ground), it will also cause one side of the contact to collect the key information while the other side of the contact does not collect it; mechanical stagnation on one side of the P gear switch will also cause the same situation. At this time, the MCU used to collect the P gear switch cannot distinguish which situation causes only one side of the contact signal to be collected. For the current CDP function logic, since the CDP function does not consider the vehicle speed, that is, at a very high speed, if the ESC receives the signal, it will also perform braking. If the CDP function request signal is indeed pressed manually, it is a normal function; however, if it is due to a fault in the P gear switch acquisition circuit or mechanical stagnation, the CDP request signal can still be issued, which will cause the vehicle to decelerate unexpectedly and suddenly, causing harm. Summary of the invention

[0004] The present disclosure proposes a P gear switch acquisition circuit to solve the above technical problems.

[0005] A P gear switch acquisition circuit includes a first power supply, a second power supply, an MCU, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a first filter capacitor, a second filter capacitor, a third filter capacitor, a fourth filter capacitor, a first MOS tube, and a second MOS tube; the MCU includes a first input port, a second input port, a third input port, and a fourth input port; the fourth resistor is a first force-sensitive resistor, which is used in conjunction with a first P gear button; one end of the first resistor is connected to the first input port, and the other end is connected to a point a between the first filter capacitor and the second resistor, and the other end of the first filter capacitor is grounded; the other end of the second resistor is connected to the third resistor, and the other end of the third resistor is connected to the first power supply; one end of the first force-sensitive resistor is connected to a point b between the second resistor and the third resistor, and the other end of the first force-sensitive resistor is connected to the fifth resistor, and the other end of the fifth resistor is grounded, and both ends of the second filter capacitor are connected to both ends of the fifth resistor; one end of the sixth resistor is connected to the second input port, and the other end is connected to a point b between the first filter capacitor and the third resistor, and the other end of the first force-sensitive resistor is connected to the fifth resistor, and the other end of the fifth resistor is grounded, and both ends of the second filter capacitor are connected to both ends of the fifth resistor; The first MOS tube is connected to the point d between the sixth resistor and the fifth resistor; one end of the first MOS tube is grounded, one end of the first MOS tube is connected to the point c between the sixth resistor and the point d, and one end of the first MOS tube is connected to the point a; the tenth resistor is a second force-sensitive resistor, which is used in conjunction with the second P gear button; one end of the seventh resistor is connected to the third input port, and the other end is connected to the point g between the third filter capacitor and the eighth resistor, and the other end of the third filter capacitor is grounded; the other end of the eighth resistor is connected to the ninth resistor, and the other end of the ninth resistor is connected to the second power supply; one end of the second force-sensitive resistor is connected to the point h between the eighth resistor and the ninth resistor, the other end of the second force-sensitive resistor is connected to the eleventh resistor, the other end of the eleventh resistor is grounded, and both ends of the third filter capacitor are connected to both ends of the eleventh resistor; one end of the twelfth resistor is connected to the fourth input port, and the other end is connected to the point j between the second force-sensitive resistor and the eleventh resistor; one end of the second MOS tube is grounded, one end of the second MOS tube is connected to the point i between the eleventh resistor and the point j, and one end of the second MOS tube is connected to the point h.

[0006] In some embodiments, the cross-section of the first P gear button is T-shaped, and the first P gear button is used in conjunction with the first force-sensitive resistor through a first shell and a first spring. The first P gear button includes a first handle and a first force-sensitive resistor cooperation rod. The first force-sensitive resistor cooperation rod extends into the first spring disposed inside the first shell. The first force-sensitive resistor is disposed at the bottom of the first shell, and the middle position of the top surface of the first force-sensitive resistor is opposite to the bottom surface of the first force-sensitive resistor cooperation rod.

[0007] In some embodiments, the cross-section of the second P gear button is T-shaped, and the second P gear button is used in conjunction with the second force-sensitive resistor through a second shell and a second spring. The first P gear button includes a second handle and a second force-sensitive resistor cooperation rod, and the second force-sensitive resistor cooperation rod extends into a second spring disposed inside the second shell. The second force-sensitive resistor is disposed at the bottom of the second shell, and the middle position of the top surface of the second force-sensitive resistor is opposite to the bottom surface of the second force-sensitive resistor cooperation rod.

[0008] In some embodiments, an accelerator pedal signal detection module is burned into the MCU.

[0009] In some embodiments, the output voltage of the first power supply is 12V.

[0010] In some embodiments, the output voltage of the second power supply is 12V.

[0011] Beneficial effects of the present disclosure: The present disclosure can avoid unexpected activation of the CDP function due to circuit failure, mechanical jamming, or other reasons, and can accurately identify the driver's intention and accurately trigger the CDP function when the driver really needs it, thereby ensuring both safety and usability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0013] Figure 1 is a schematic diagram showing the structure of a P-speed switch acquisition circuit according to some embodiments of the present disclosure.

[0014] Figure 2 It is a schematic diagram showing the coordinated use of a P-gear button and a force-sensitive resistor according to some embodiments of the present disclosure.

[0015] Figure 3 It is a schematic diagram of the structure of the P gear switch acquisition circuit in the background technology.

[0016] The markings in the figure are as follows: 1. First P gear button; 2. First housing; 3. First spring; 4. First force-sensitive resistor. DETAILED DESCRIPTION

[0017] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless otherwise specifically stated.

[0018] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0019] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0020] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0021] At present, the existing solutions cannot distinguish whether it is a situation where only one contact signal is valid due to a person pressing the wrong button, a circuit failure on one side, or a mechanical jam on one side. So when only one contact signal is valid, there are two strategies: one is to consider the P gear button to be valid, and the other is to consider the P gear button to be invalid.

[0022] The P gear switch is used to realize two functions, one is the P gear function (pulling up the EPB at the same time), and the other is the CDP function (pressing and holding the P gear button to achieve braking when the brake fails).

[0023] For the P gear function, if only one side of the contact signal is valid, the P gear button is considered invalid, and the usability will be greatly reduced, because the P gear cannot be engaged if the driver presses the wrong position (but the driver wants to engage the P gear at this time);

[0024] If only one side of the contact signal is valid, the P gear button is considered valid. In this case, due to mechanical jamming or failure of the contact acquisition circuit on one side, the P gear will be shifted into P gear. This is not very reasonable, but the current P gear logic is that the P gear valid signal will be accepted only when the vehicle is stationary. Therefore, if only one side of the contact signal is valid, it is considered that the P gear button is valid and there is no problem with the P gear function.

[0025] For the CDP function, if only one side of the contact signal is valid, the P gear button is considered valid. Then mechanical jamming and one side of the contact circuit failure will trigger the CDP function (the CDP function does not consider the vehicle speed, that is, the CDP function can also be triggered when the vehicle speed is very high). At this time, the vehicle is equivalent to stepping on the brakes unexpectedly, causing the vehicle to become unstable or rear-end-ended by the vehicle behind. Due to the large hazard, the current functional safety requirement is that the P gear switch is considered valid only when both sides of the contact are valid at the same time to avoid the hazard; but if only one side of the contact signal is valid, the P gear button is considered invalid (the P gear switch is considered valid only when both sides of the contact are valid at the same time), then in an emergency situation where the brakes fail, the driver is likely to press the P gear switch by mistake. At this time, the driver wants to trigger the CDP function, but cannot trigger it, resulting in an accident. There is currently no better solution to solve this problem.

[0026] The current CDP function logic is to only judge the CDP request signal sent by the combination switch, that is, to perform corresponding braking upon receiving the CDP request signal, which will aggravate unexpected braking caused by problems with the P gear switch.

[0027] In view of this, the present disclosure proposes a P gear switch acquisition circuit, which can not only avoid the unexpected activation of the CDP function due to circuit failure, mechanical jamming, or other reasons, but also accurately identify the driver's intention and accurately trigger the CDP function when the driver really needs it, thereby ensuring both safety and usability.

[0028] like Figure 1As shown, a P gear switch acquisition circuit is characterized in that it includes a first power supply, a second power supply, an MCU, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a first filter capacitor, a second filter capacitor, a third filter capacitor, a fourth filter capacitor, a first MOS tube, and a second MOS tube; the MCU includes a first input port, a second input port, a third input port, and a fourth input port; the fourth resistor is a first force-sensitive resistor, which is used in conjunction with the first P gear button; one end of the first resistor is connected to the first input port, and the other end is connected to a point a between the first filter capacitor and the second resistor, and the other end of the first filter capacitor is grounded; the other end of the second resistor is connected to the third resistor, and the other end of the third resistor is connected to the first power supply; one end of the first force-sensitive resistor is connected to a point b between the second resistor and the third resistor, the other end of the first force-sensitive resistor is connected to the fifth resistor, the other end of the fifth resistor is grounded, and both ends of the second filter capacitor are connected to both ends of the fifth resistor; one end of the sixth resistor is connected to the second input port, and the other end is connected to a point b between the second resistor and the third resistor The first force-sensitive resistor is connected to the point d between the fifth resistor; one end of the first MOS tube is grounded, one end of the first MOS tube is connected to the point c between the sixth resistor and the point d, and one end of the first MOS tube is connected to the point a; the tenth resistor is a second force-sensitive resistor, which is used in conjunction with the second P gear button; one end of the seventh resistor is connected to the third input port, and the other end is connected to the point g between the third filter capacitor and the eighth resistor, and the other end of the third filter capacitor is grounded; the other end of the eighth resistor is connected to the ninth resistor, and the other end of the ninth resistor is connected to the second power supply one end of the second force-sensitive resistor is connected to the h point between the eighth resistor and the ninth resistor, the other end of the second force-sensitive resistor is connected to the eleventh resistor, the other end of the eleventh resistor is grounded, and the two ends of the third filter capacitor are connected to the two ends of the eleventh resistor; one end of the twelfth resistor is connected to the fourth input port, and the other end is connected to the j point between the second force-sensitive resistor and the eleventh resistor; one end of the second MOS tube is grounded, one end of the second MOS tube is connected to the i point between the eleventh resistor and the j point, and one end of the second MOS tube is connected to the h point.

[0029] like Figure 1As shown, it should be noted that the first P gear button and the second P gear button are combined into an integral P gear button; R1 is the first resistor, R2 is the second resistor, R3 is the third resistor, R4 is the fourth resistor, R5 is the fifth resistor, R11 is the sixth resistor, R6 is the seventh resistor, R7 is the eighth resistor, R8 is the ninth resistor, R9 is the tenth resistor, R10 is the eleventh resistor, and R12 is the twelfth resistor. Figure 1 As shown, the second filter capacitor is connected to both ends of the fifth resistor via point e and point f. The fourth filter capacitor is connected to both ends of the eleventh resistor via point k and point l.

[0030] like Figure 2 As shown, the cross-section of the first P gear button 1 is T-shaped. The first P gear button is used in conjunction with the first force-sensitive resistor 4 through the first shell 2 and the first spring 3. The first P gear button includes a first handle and a first force-sensitive resistor cooperation rod. The first force-sensitive resistor cooperation rod extends into the first spring arranged inside the first shell. The first force-sensitive resistor is arranged at the bottom of the first shell, and the middle position of the top surface of the first force-sensitive resistor is opposite to the bottom surface of the first force-sensitive resistor cooperation rod.

[0031] In some embodiments, the cross-section of the second P gear button is T-shaped, and the second P gear button is used in conjunction with the second force-sensitive resistor through a second shell and a second spring. The first P gear button includes a second handle and a second force-sensitive resistor cooperation rod, and the second force-sensitive resistor cooperation rod extends into a second spring disposed inside the second shell. The second force-sensitive resistor is disposed at the bottom of the second shell, and the middle position of the top surface of the second force-sensitive resistor is opposite to the bottom surface of the second force-sensitive resistor cooperation rod.

[0032] In some embodiments, an accelerator pedal signal detection module is burned into the MCU.

[0033] In some embodiments, the output voltage of the first power supply is 12V.

[0034] In some embodiments, the output voltage of the second power supply is 12V.

[0035] P gear switch: Currently, P gear has become a mainstream gear configuration, in which P gear is a button located on the side of the switch, and engaging P gear will simultaneously pull up the EPB (electronic parking brake system).

[0036] EPB: The abbreviation of Electrical Park Brake, which means electronic parking brake system, can realize vehicle parking brake through electronic control.

[0037] CDP: The abbreviation of Controller Deceleration Parking, which means the deceleration control of the parking brake. When the brake pedal fails, the driver can brake by long pressing the P gear switch.

[0038] ESC: The abbreviation of Electronic Stability Controller, which means electronic stability control system, is used to control vehicle braking and body stability.

[0039] like Figure 1 As shown, the rectangle on the right is a circuit board, which contains an MCU and a 12V power supply. The upper and lower parts are acquisition circuits for two contact switches. The two circuits are exactly the same, so this article only focuses on explaining the upper part. The reason for setting up two acquisition circuits is to improve the fault diagnosis coverage.

[0040] There is a 12V power supply inside the circuit board, connected to R3 and R2 (the resistance of R2 is much larger than that of R3, and similarly the resistance of R7 is much larger than that of R8, to ensure that point h can still maintain a high level when the MOS tube is turned on) as pull-up resistors, which also have a current limiting effect. R1 and R11 are also current limiting resistors for protecting the MCU. C1 is a filter capacitor, and P1 and P2 are two input ports of the MCU, respectively. P1 is valid at a low level and P2 is valid at a high level.

[0041] The left side of the circuit board is the external circuit. R4 is a force-sensitive resistor, and its resistance will decrease when it is subjected to pressure.

[0042] Q1 is a MOS tube. When point c is at an appropriate high level, the MOS tube will be turned on and off; when the voltage at point c is at a low level, the MOS tube will be turned off and off. However, when the voltage at point c is too high, the MOS tube will be damaged, and the MOS tube will be turned off and off and will not recover.

[0043] R5 is a voltage divider resistor and C2 is a filter capacitor.

[0044] Specific working logic: When the P gear switch is pressed, button 1 and button 2 will be pressed at the same time (since the circuits controlled by button 1 and button 2 are exactly the same, only the button 1 circuit is analyzed here), button 1 is connected to R4, and when button 1 is pressed, R4 is subjected to pressure. R4 is a force-sensitive resistor (its resistance decreases when subjected to pressure). When R4 decreases, the current flowing through R3, R4 and R5 increases, and the R5 voltage divider increases, so the potential at point e increases. The potentials at points e, d, and c are the same, so the potential at point c increases to a high level. At this time, the MOS tube Q1 is turned on and the potential at point a drops to a low level.

[0045] The P1 and P2 ports of the MCU collect the voltage at point a and point c respectively. According to the previous analysis, when button1 is pressed, point a is low voltage and point c is high voltage. The following logic is performed inside the MCU: only when the MCU collects that P1 is low level and P2 is high level, it considers that button1 is pressed. We define this situation as button1 is pressed effectively.

[0046] Similarly, when the MCU's P3 port collects a low level and the P4 port collects a high level, it is considered that button2 is pressed. We define this situation as button2 being pressed effectively.

[0047] MCU output logic: As long as the MCU detects that button1 is pressed effectively or button2 is pressed effectively, it will consider that the P gear switch is pressed effectively and output the network signal of the P gear switch being pressed.

[0048] Strategy of CDP function: To further ensure the correct execution of the CDP function, the present invention makes the following changes to the trigger logic of CDP: After receiving the CDP request signal from the combination switch, the CDP function also judges the accelerator pedal signal. Only when the CDP request signal is valid and the accelerator pedal signal is invalid, the ESC executes the CDP function.

[0049] As mentioned above, regarding the problem of people pressing the P gear button off-center: when people press the P gear switch off-center, button1 will be valid but button2 will be invalid (or button2 will be valid but button1 will be invalid), but button1 can still collect pressure (because people did press it), and MCU will take the OR of button1 valid and button2 valid, so the P gear switch pressing signal can still be sent when people press it off-center.

[0050] For the problem of circuit failure: if point b is open, point c is low level, Q1 will not conduct, and the potential at point a is also high level, then the acquisition result is that button1 is invalid; if point d or point c is open, the level at point c is low level, Q1 will not conduct, and the acquisition result is still that button1 is invalid; if point e is open, point c is 12V high level, and the appropriate Q1 is matched when designing the circuit (Q1 will only conduct when point c is at a suitable voltage, and if it exceeds a certain threshold, the MOS will break down and be damaged). At this time, the voltage at point c is higher than the maximum voltage that the MOS tube gate can withstand, resulting in Q 1 breaks down, so Q1 will not conduct. Therefore, although P2 collects high voltage at this time, P1 does not collect low voltage, so the collection result is still that button1 is invalid; if there is a short circuit between point b and point d (the same applies to point e or point c), the potential of point e increases, and similarly the potential of point c increases. At this time, the voltage will still be higher than the breakdown voltage of Q1, which will cause Q1 to break down, so the collection result is still that button1 is invalid; if there is a short circuit between point f and point e (the same applies to point d, point c, and point b), the potential of point c is still low, and Q1 will still not conduct, so the collection result is still that button1 is invalid;

[0051] In summary, circuit failure will not cause the acquisition results of ports P1 and P2 to be valid at the same time, that is, based on the circuit design disclosed in the present invention, even if the circuit fails, button1 will not be pressed effectively. The same is true for button2. Therefore, circuit failure will not cause the MCU to collect the situation that only one contact of button1 or button2 is pressed effectively (this ensures that the situation that only one contact is pressed is caused by a person pressing it incorrectly).

[0052] based on Figure 2 , we can get the unpressed state, pressed state, stuck in the middle state, and stuck at the bottom state. For the mechanical stuck state of the P gear switch: the spring does not directly press on R4 (the spring diameter is greater than the length of R4), and R4 is directly pressed by the button when pressed. Force analysis is performed on the above four states (without considering gravity and friction).

[0053] When the P gear switch is not pressed, the button is subjected to the upward elastic force of the spring and the reaction force of the shell. At this time, R4 is not subjected to pressure (the length of R4 is smaller than the diameter of the spring).

[0054] When the P gear switch is pressed, the button is pressed downward by the person, the spring is pushed upward, and R4 exerts a reaction force on the button. At this time, R4 is under pressure.

[0055] When the P gear switch is stuck in the middle, the button is subject to the upward elastic force of the spring and the downward reaction force given by the stuck state, and R4 is not under pressure at this time;

[0056] When the P gear switch is stuck at the bottom, the button is in contact with R4 but is not subjected to force. The upward elastic force of the spring and the reaction force provided by the button at the stuck position are balanced.

[0057] Only when the key is stuck in the deformation stroke of R4, R4 will be stressed. However, since the deformation stroke of the force sensitive resistor is very small (much smaller than that of a general switch), the probability of the key being stuck in the deformation stroke of R4 is very small (much smaller than that of a general contact switch). Therefore, for the present disclosure, mechanical sticking will not cause abnormal stress on R4 in most cases, and one or two contacts will not be effective due to mechanical sticking.

[0058] The disclosure requires that the CDP function simultaneously determines that the accelerator pedal signal is invalid while determining that the CDP request signal is valid. In this way, if the vehicle is driving normally, the accelerator pedal is usually pressed. At this time, if the P gear switch sends a CDP valid signal for various reasons, the ESC will not perform braking; if the vehicle brake fails, the driver wants to trigger the CDP function by long pressing the P gear switch, then the driver will definitely not step on the accelerator pedal, and the CDP function will be triggered normally. Through this strategy, a double insurance is achieved to prevent the CDP function from being triggered unexpectedly.

[0059] The key technical points of the present invention are: ingenious use of the characteristics of force-sensitive resistors, MOS tubes and resistor voltage dividers to achieve accurate recognition of the driver's intentions, and at the same time, by setting the verification of the low level of the P1 port and the high level of the P2 port of the MCU, all situations in which the acquisition results are erroneous due to circuit failure are eliminated. In addition, the CDP function is added in combination with the usage scenario to judge the accelerator pedal signal, thereby providing a full-link guarantee for the accurate and safe implementation of the CDP function.

[0060] So far, the P gear switch acquisition circuit according to the present disclosure has been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0061] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A P gear switch acquisition circuit, characterized in that: Including a first power supply, a second power supply, an MCU, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a first filter capacitor, a second filter capacitor, a third filter capacitor, a fourth filter capacitor, a first MOS tube, and a second MOS tube; The MCU includes a first input port, a second input port, a third input port, and a fourth input port; The fourth resistor is a first force-sensitive resistor, used in conjunction with the first P gear button; One end of the first resistor is connected to the first input port, and the other end is connected to point a between the first filter capacitor and the second resistor, and the other end of the first filter capacitor is grounded; The other end of the second resistor is connected to the third resistor, and the other end of the third resistor is connected to the first power supply; One end of the first force-sensitive resistor is connected to point b between the second resistor and the third resistor, the other end of the first force-sensitive resistor is connected to the fifth resistor, the other end of the fifth resistor is grounded, and both ends of the second filter capacitor are connected to both ends of the fifth resistor; One end of the sixth resistor is connected to the second input port, and the other end is connected to a point d between the first force-sensitive resistor and the fifth resistor; One end of the first MOS transistor is grounded, one end of the first MOS transistor is connected to point c between the sixth resistor and point d, and one end of the first MOS transistor is connected to point a; The tenth resistor is a second force-sensitive resistor, used in conjunction with the second P gear button; One end of the seventh resistor is connected to the third input port, and the other end is connected to a point g between the third filter capacitor and the eighth resistor, and the other end of the third filter capacitor is grounded; The other end of the eighth resistor is connected to the ninth resistor, and the other end of the ninth resistor is connected to the second power supply; One end of the second force-sensitive resistor is connected to the h point between the eighth resistor and the ninth resistor, the other end of the second force-sensitive resistor is connected to the eleventh resistor, the other end of the eleventh resistor is grounded, and both ends of the third filter capacitor are connected to both ends of the eleventh resistor; One end of the twelfth resistor is connected to the fourth input port, and the other end is connected to a point j located between the second force-sensitive resistor and the eleventh resistor; One end of the second MOS tube is grounded, one end of the second MOS tube is connected to a point i between the eleventh resistor and a point j, and one end of the second MOS tube is connected to a point h.

2. The P gear switch acquisition circuit according to claim 1, characterized in that: The cross-section of the first P gear button is T-shaped. The first P gear button is used in conjunction with the first force-sensitive resistor through a first shell and a first spring. The first P gear button includes a first handle and a first force-sensitive resistor cooperating rod. The first force-sensitive resistor cooperating rod extends into the first spring arranged inside the first shell. The first force-sensitive resistor is arranged at the bottom of the first shell, and the middle position of the top surface of the first force-sensitive resistor is opposite to the bottom surface of the first force-sensitive resistor cooperating rod.

3. The P gear switch acquisition circuit according to claim 1, characterized in that: The cross-section of the second P gear button is T-shaped. The second P gear button is used in conjunction with the second force-sensitive resistor through a second shell and a second spring. The first P gear button includes a second handle and a second force-sensitive resistor cooperation rod. The second force-sensitive resistor cooperation rod extends into the second spring arranged inside the second shell. The second force-sensitive resistor is arranged at the bottom of the second shell, and the middle position of the top surface of the second force-sensitive resistor is opposite to the bottom surface of the second force-sensitive resistor cooperation rod.

4. The P gear switch acquisition circuit according to claim 1, characterized in that: The MCU is programmed with an accelerator pedal signal detection module.

5. The P gear switch acquisition circuit according to claim 1, characterized in that: The output voltage of the first power supply is 12V.

6. The P gear switch acquisition circuit according to claim 1, characterized in that: The output voltage of the second power supply is 12V.

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