阅读说明：本技术 抑制汽车尾门掉尾的驱动电路及控制方法 (Drive circuit for inhibiting tail falling of automobile tail door and control method ) 是由 赵战伟 于 2021-08-05 设计创作，主要内容包括：本发明涉及一种抑制汽车尾门掉尾的驱动电路及控制方法,包括型号为MC9S12G128的单片机、霍尔信号采集模块、PWM波输出控制模块、继电器控制模块,单片机的引脚21、引脚23、引脚27和引脚29分别电性连接霍尔信号采集模块的至少一输出端；单片机的引脚17和引脚18分别电性连接PWM波输出控制模块的至少一输入端；单片机的引脚52～58分别电性连接继电器控制模块的至少一输入端。本发明采用的电路结构使得撑杆电机通过短接制动获取一部分制动力来降低尾门运行速度,当汽车的尾门运行至一定低位时,使得撑杆无须承担过多尾门的重量,大部分的撑杆都能适用,这样也可较方便的实现减速同时也降低了实施成本。(The invention relates to a drive circuit for inhibiting tail falling of an automobile tail door and a control method, and the drive circuit comprises a single chip microcomputer with the model of MC9S12G128, a Hall signal acquisition module, a PWM wave output control module and a relay control module, wherein a pin 21, a pin 23, a pin 27 and a pin 29 of the single chip microcomputer are respectively and electrically connected with at least one output end of the Hall signal acquisition module; the pin 17 and the pin 18 of the singlechip are respectively and electrically connected with at least one input end of the PWM wave output control module; the pins 52-58 of the single chip microcomputer are electrically connected with at least one input end of the relay control module respectively. The circuit structure adopted by the invention enables the stay bar motor to obtain a part of braking force through short-circuit braking to reduce the running speed of the tail gate, when the tail gate of the automobile runs to a certain low position, the stay bar does not need to bear the weight of too much tail gate, and most of the stay bars can be suitable for use, so that the speed reduction can be conveniently realized, and the implementation cost is also reduced.)

1. The utility model provides a restrain car tail-gate and fall drive circuit of tail which characterized in that: the device comprises a single chip microcomputer with the model number of MC9S12G128, a Hall signal acquisition module, a PWM wave output control module and a relay control module;

the pin 21, the pin 23, the pin 27 and the pin 29 of the single chip microcomputer are respectively and electrically connected with at least one output end of the Hall signal acquisition module;

the pin 17 and the pin 18 of the single chip microcomputer are respectively and electrically connected with at least one input end of the PWM wave output control module;

pins 52-58 of the single chip microcomputer are respectively and electrically connected with at least one input end of the relay control module;

the relay control module comprises a Darlington tube and a relay;

the model of the Darlington tube is ULQ2003-16PIN, a PIN 10 of the Darlington tube is electrically connected with the positive control end of the relay, and a PIN 11 of the Darlington tube is electrically connected with the negative control end of the relay;

the first motor control end of the relay is electrically connected with the positive pole of the stay bar motor, and the second motor control end of the relay is electrically connected with the negative pole of the stay bar motor;

the PWM wave output control module comprises a first PWM wave output control circuit and a second PWM wave output control circuit;

a first output end (A1) of the first PWM wave output control circuit is electrically connected with a first receiving end of the relay;

and a second output end (A2) of the second PWM wave output control circuit is electrically connected with a second receiving end of the relay.

2. The drive circuit according to claim 1, wherein:

the first PWM wave output control circuit comprises a first triode (Q10), a second triode (Q11) and a first MOS (Q15); after passing through the first triode (Q10) and the second triode (Q11), the PWM wave signal is transmitted to the first MOS tube (Q15), one end of the first MOS tube (Q15) is connected to the ground through a first resistor (R76), and the other end of the first MOS tube is connected with a first output end (A1) of the first PWM wave output control circuit;

the second PWM wave output control circuit comprises a third triode (Q13), a fourth triode (Q12) and a second MOS tube (Q6); after passing through the third transistor (Q13) and the fourth transistor (Q12), the PWM wave signal is transmitted to the second MOS transistor (Q6), one end of the second MOS transistor (Q6) is connected to ground through a second resistor (R117), and the other end of the second MOS transistor is connected to the second output end (a 2) of the second PWM wave output control circuit.

3. The drive circuit according to claim 1, wherein:

the first input end (PP 0) of the first PWM wave output control circuit is electrically connected with a pin 17 of the single chip microcomputer, and the second input end (PP 1) of the second PWM wave output control circuit is electrically connected with a pin 18 of the single chip microcomputer.

4. The drive circuit according to claim 1, wherein:

pin 52 electric connection of singlechip the pin 7 of darlington pipe, pin 53 electric connection of singlechip the pin 6 of darlington pipe, pin 54 electric connection of singlechip the pin 5 of darlington pipe, pin 55 electric connection of singlechip the pin 4 of darlington pipe, pin 56 electric connection of singlechip the pin 3 of darlington pipe, pin 57 electric connection of singlechip the pin 2 of darlington pipe, the pin 58 electric connection of singlechip the pin 1 of darlington pipe.

5. A control method for restraining the tail falling of an automobile tail gate is characterized in that: the drive circuit for suppressing the falling of the tail of the automobile tail gate according to claim 1, wherein the method comprises the following steps:

firstly, a Hall signal acquisition module sends an acquired Hall signal to a single chip microcomputer after filtering processing;

secondly, the single chip microcomputer receives the Hall signal and obtains the current tail gate running speed, and the current tail gate running speed is compared with a preset threshold value in the single chip microcomputer;

if the running speed is higher than the preset threshold value, judging that the speed is too high, and controlling a PWM wave output control module to reduce the duty ratio of the currently output PWM wave by the single chip microcomputer so as to reduce the running speed of the tail gate;

until the running speed is equal to the preset threshold value, the goal of tail gate deceleration is achieved;

step four, when the duty ratio of the PWM wave output by the PWM wave output control module is reduced to 0, but the running speed is still larger than the preset threshold value;

the single chip microcomputer sends a control signal to the Darlington tube; meanwhile, the single chip microcomputer sends PWM waves with duty ratios both being full values to a first PWM wave output control circuit and a second PWM wave output control circuit in the PWM wave output control module;

after the darlington tube receives the control signal, 12V voltage is output to the positive control end and the negative control end of the relay through the darlington tube, so that the positive control end and the negative control end of the relay are disconnected, and the relay is enabled to be recovered to a non-conducting state, at the moment, the positive electrode of the strut rod motor is electrically connected to the first output end (A1) of the first PWM wave output control circuit, and the negative electrode of the strut rod motor is electrically connected to the second output end (A2) of the second PWM wave output control circuit;

after the first PWM wave output control circuit and the second PWM wave output control circuit receive the PWM wave with the full duty ratio, the positive pole of the strut motor is conducted through the first output end (A1) and is connected to the ground in an abutting mode, and the negative pole of the strut motor is conducted through the second output end (A2) and is connected to the ground in an abutting mode.

6. The method of claim 5, wherein: after the first PWM wave output control circuit and the second PWM wave output control circuit receive the PWM wave with the full duty ratio, the positive pole of the strut motor is conducted through the first output terminal (a 1) and is coupled to the ground, and the negative pole of the strut motor is conducted through the second output terminal (a 2) and is coupled to the ground, the method further includes:

the single chip microcomputer sends PWM waves with non-full duty ratio to the first PWM wave output control circuit, and the single chip microcomputer sends PWM waves with full duty ratio to the second PWM wave output control circuit;

when the first PWM wave output control circuit receives the PWM wave with the non-full duty ratio and the second PWM wave output control circuit receives the PWM wave with the full duty ratio, the positive pole of the stay bar motor is indirectly opened and closed to the ground through the first output end (A1), and the negative pole of the stay bar motor is conducted and connected to the ground through the second output end (A2).

Technical Field

The invention relates to a drive circuit, in particular to a drive circuit for inhibiting tail falling of an automobile tail gate and a control method.

Background

Along with the improvement of comfort level and operation intellectuality requirement when people used the car, adopt electronic mode to realize the automatic switching of car tail-gate and become a trend gradually, most well high-grade car has been equipped with the electronic tail-gate of car. When the automobile trunk is used, the automobile trunk door can be controlled in an electric mode, and then the trunk of the automobile is opened or closed. Generally, the opening and closing of the tail gate of the automobile are realized by the expansion and contraction of an electric stay bar, the electric stay bar is driven by a motor, and the motor needs to be controlled by a control system.

The control scheme of the electric automobile tail gate effectively solves the inconvenience of the traditional manual opening and closing tail gate, and the following defects are found in the long-term use process:

firstly, when the tail-gate of car moves to a certain low level, the vaulting pole often can't support the tail-gate and to its applied pressure under the current position state, causes the holding power not enough, leads to pounding the door phenomenon and frequently takes place. Therefore, a specific stay bar is required to be matched with a corresponding control system, so that the stay bar which can be selected is single, the cost of the control system relative to the stay bar is greatly increased, the overall implementation cost is greatly increased, and the market popularization of the product is not facilitated;

secondly, the existing control scheme of the tail door of the electric automobile has the defects of high heat generation and low stability, so that the loss of a strut motor is large, and the problem that the motor is easily damaged along with the lapse of working time is solved;

thirdly, the control scheme of the existing electric automobile tail gate has the problem of poor design, so that the reliability is low, and potential safety hazards are easy to exist.

Disclosure of Invention

The invention provides a drive circuit for inhibiting tail falling of an automobile tail gate.

In order to achieve the purpose, the invention adopts the technical scheme that:

a drive circuit for inhibiting tail falling of an automobile tail door comprises a single chip microcomputer with the model number of MC9S12G128, a Hall signal acquisition module, a PWM wave output control module and a relay control module, wherein a pin 21, a pin 23, a pin 27 and a pin 29 of the single chip microcomputer are respectively and electrically connected with at least one output end of the Hall signal acquisition module;

the pin 17 and the pin 18 of the single chip microcomputer are respectively and electrically connected with at least one input end of the PWM wave output control module;

pins 52-58 of the single chip microcomputer are respectively and electrically connected with at least one input end of the relay control module;

the relay control module comprises a Darlington tube and a relay;

the model of the Darlington tube is ULQ2003-16PIN, a PIN 10 of the Darlington tube is electrically connected with the positive control end of the relay, and a PIN 11 of the Darlington tube is electrically connected with the negative control end of the relay;

the first motor control end of the relay is electrically connected with the positive pole of the stay bar motor, and the second motor control end of the relay is electrically connected with the negative pole of the stay bar motor;

the PWM wave output control module comprises a first PWM wave output control circuit and a second PWM wave output control circuit;

a first output end of the first PWM wave output control circuit is electrically connected with a first receiving end of the relay;

and a second output end of the second PWM wave output control circuit is electrically connected with a second receiving end of the relay.

The relevant content in the above technical solution is explained as follows:

1. in the above scheme, the first PWM wave output control circuit includes a first transistor, a second transistor, and a first MOS transistor; after the PWM wave signal passes through the first triode and the second triode, the PWM wave signal is transmitted to the first MOS tube, one end of the first MOS tube is connected to the ground through a first resistor, and the other end of the first MOS tube is connected with a first output end of the first PWM wave output control circuit;

the second PWM wave output control circuit comprises a third triode, a fourth triode and a second MOS tube; and after passing through the third triode and the fourth triode, the PWM wave signal is transmitted to the second MOS tube, one end of the second MOS tube is connected to the ground through a second resistor, and the other end of the second MOS tube is connected with a second output end of the second PWM wave output control circuit.

2. In the above scheme, the first input terminal of the first PWM wave output control circuit is electrically connected to the pin 17 of the single chip microcomputer, and the second input terminal of the second PWM wave output control circuit is electrically connected to the pin 18 of the single chip microcomputer. Therefore, the single chip microcomputer can send PWM wave signals to the corresponding 2 input ends of the PWM wave output control module through the 2 output ends, and therefore the duty ratio of the PWM waves output by the first PWM wave output control circuit and the second PWM wave output control circuit is controlled.

3. In the above scheme, pin 52 electric connection of singlechip the pin 7 of darlington pipe, pin 53 electric connection of singlechip the pin 6 of darlington pipe, pin 54 electric connection of singlechip the pin 5 of darlington pipe, pin 55 electric connection of singlechip the pin 4 of darlington pipe, pin 56 electric connection of singlechip the pin 3 of darlington pipe, pin 57 electric connection of singlechip the pin 2 of darlington pipe, pin 58 electric connection of singlechip the pin 1 of darlington pipe. The signal of singlechip output carries out signal isolation and improves the driving force of signal after 7 input inputs that darlington pipe corresponds to can avoid the later stage circuit to lead to the singlechip to be burnt out when short circuit scheduling problem appears.

In order to achieve the purpose, the invention adopts another technical scheme that:

a control method for suppressing a tail gate falling of an automobile, the method comprising:

firstly, a Hall signal acquisition module sends an acquired Hall signal to a single chip microcomputer after filtering processing;

secondly, the single chip microcomputer receives the Hall signal and obtains the current tail gate running speed, and the current tail gate running speed is compared with a preset threshold value in the single chip microcomputer;

if the running speed is higher than the preset threshold value, judging that the speed is too high, and controlling a PWM wave output control module to reduce the duty ratio of the currently output PWM wave by the single chip microcomputer so as to reduce the running speed of the tail gate;

until the running speed is equal to the preset threshold value, the goal of tail gate deceleration is achieved;

step four, when the duty ratio of the PWM wave output by the PWM wave output control module is reduced to 0, but the running speed is still larger than the preset threshold value;

the single chip microcomputer sends a control signal to the Darlington tube; meanwhile, the single chip microcomputer sends PWM waves with duty ratios both being full values to a first PWM wave output control circuit and a second PWM wave output control circuit in the PWM wave output control module;

after receiving the control signal, the darlington tube outputs 12V voltage to the positive control end and the negative control end of the relay through the darlington tube, so that the positive control end and the negative control end of the relay are disconnected, and the relay is restored to a non-conduction state, at the moment, the positive electrode of the strut motor is electrically connected to the first output end of the first PWM wave output control circuit, and the negative electrode of the strut motor is electrically connected to the second output end of the second PWM wave output control circuit;

after the first PWM wave output control circuit and the second PWM wave output control circuit receive the PWM wave with the full duty ratio, the positive pole of the strut motor is conducted through the first output end and is connected to the ground in an abutting mode, and the negative pole of the strut motor is conducted through the second output end and is connected to the ground in an abutting mode.

The relevant content in the above technical solution is explained as follows:

1. in the above scheme, according to the method, the first output end of the first PWM wave output control circuit is always open to the ground through the PWM wave with the full duty ratio, and the second output end of the second PWM wave output control circuit is always open to the ground through the PWM wave with the full duty ratio, so that two ends of the anode and the cathode of the strut motor are short-circuited, and under the condition that the two ends of the strut motor are short-circuited, the faster the strut motor is, the larger the braking force generated by the strut motor is, the slower the strut motor is, the smaller the braking force generated by the strut motor is, and the strut motor can be braked and decelerated due to the characteristics, so that the deceleration target is achieved.

2. In the foregoing solution, after the first PWM wave output control circuit and the second PWM wave output control circuit receive the PWM wave with the full duty ratio, the positive electrode of the strut motor is conducted through the first output terminal and is coupled to the ground, and the negative electrode of the strut motor is conducted through the second output terminal and is coupled to the ground, the method further includes:

the single chip microcomputer sends PWM waves with non-full duty ratio to the first PWM wave output control circuit, and the single chip microcomputer sends PWM waves with full duty ratio to the second PWM wave output control circuit;

when the first PWM wave output control circuit receives the PWM wave with the non-full duty ratio and the second PWM wave output control circuit receives the PWM wave with the full duty ratio, the positive pole of the stay bar motor is indirectly opened and closed to the ground through the first output end, and the negative pole of the stay bar motor is conducted through the second output end and is connected to the ground in an abutting mode. According to the method, the first output end of the first PWM wave output control circuit is indirectly opened and closed to the ground through the PWM waves with the non-full duty ratio, the second output end of the second PWM wave output control circuit is always opened to the ground through the PWM waves with the full duty ratio, so that the positive pole of the stay bar motor jumps between the ground and the suspension, the negative pole of the stay bar motor is always opened to the ground, and the deceleration amplitude of the stay bar motor can be adjusted through the duty ratio of the PWM waves input to the first PWM wave output control circuit by the single chip microcomputer.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:

1. the circuit structure adopted by the invention enables the stay bar motor to obtain a part of braking force through short-circuit braking to reduce the running speed of the tail gate, when the tail gate of the automobile runs to a certain low position, the stay bar does not need to bear the weight of too much tail gate, and most of the stay bars can be suitable for use, so that the speed reduction can be conveniently realized, and the implementation cost is also reduced;

2. according to the invention, the braking force is obtained by adopting a short-circuit braking mode when the speed is too high to reduce the tail gate speed, so that the heating value of the whole circuit system is small, the stability is high, the motor is not easy to damage along with the lapse of working time, and the loss of the stay bar motor can be reduced;

3. the circuit structure of the invention has high reliability and high safety.

Drawings

FIG. 1 is a block diagram of the overall structure of a driving circuit for suppressing the falling of the tail of an automobile tail gate in the embodiment of the invention;

FIG. 2 is a schematic circuit structure diagram of a single chip microcomputer in the embodiment of the invention;

FIG. 3 is a schematic diagram of a filter circuit structure of a Hall signal acquisition module according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a filter circuit structure of a Hall signal acquisition module according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a first group of PWM wave output control circuits in the PWM wave output control module according to the embodiment of the present invention;

fig. 6 is a schematic structural diagram of a second group of PWM wave output control circuits in the PWM wave output control module according to the embodiment of the present invention;

FIG. 7 is a schematic diagram of a Darlington transistor circuit in a relay control module according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a relay circuit in the relay control module according to an embodiment of the present invention;

fig. 9 is a flowchart of a control method for suppressing the falling of the tail of the car tail gate in the embodiment of the present invention.

In the above drawings: u5, Darlington tubes; a1, a first output end; a2, a second output end; q10, the first triode; q11, the second triode; q15, a first MOS tube; r76, a first resistor; q13, third triode; q12, fourth triode; q6 and a second MOS tube; r117, a second resistor; PP0, a first input; PP1, a second input terminal.

Detailed Description

The invention is further described with reference to the following figures and examples:

the first embodiment is as follows: referring to the attached drawing 1, the driving circuit for inhibiting the tail falling of the automobile tail gate comprises a single chip microcomputer, a Hall signal acquisition module, a PWM wave output control module and a relay control module. The model of the single chip microcomputer is preferably MC9S12G128, other single chip microcomputers with the same or similar functions can be selected, and the single chip microcomputers can be flexibly selected by a person skilled in the art according to needs.

Referring to fig. 2 and 3, the pin 21, the pin 23, the pin 27, and the pin 29 of the single chip are respectively electrically connected to at least one output terminal of the hall signal acquisition module. In this embodiment, the number of output ends of the hall acquisition module electrically connected to the single chip microcomputer is 4, and the number of output ends may be 1, 2, 3, or 5, and the like in other embodiments. Preferably, the pin 21 of the single chip microcomputer is electrically connected with the output end PP4 in the hall signal acquisition module; the pin 23 of the singlechip is electrically connected with the output end PP6 of the Hall signal acquisition module; the pin 27 of the singlechip is electrically connected with an output end PT5 in the Hall signal acquisition module; the pin 29 of the single chip microcomputer is electrically connected with an output end PT3 in the Hall signal acquisition module. Through the connection mode, the Hall signal acquisition module can send the acquired Hall signals to the 4 input ends corresponding to the single chip microcomputer through the 4 output ports of the Hall signal acquisition module after the Hall signals are subjected to filtering processing, and therefore the Hall signals are acquired.

Referring to fig. 3, a filter circuit structure in the HALL signal acquisition module in this embodiment includes a HALL signal input port BHL, a 12V pull-up power input port HALL _12V, a filter capacitor C40 ground port, a filter capacitor C20 ground port, an output port PP4, and an output port PT 3.

Referring to fig. 4, another filter circuit structure in the HALL signal acquisition module in this embodiment includes a HALL signal input port BHH, a 12V pull-up power input port HALL _12V, a filter capacitor C41 ground port, a filter capacitor C21 ground port, an output port PP5, and an output port PT 5.

The filter circuit may also be another circuit structure capable of filtering the collected hall signal, and the circuit structure of the filter circuit is not limited in this embodiment.

Referring to fig. 2, 5 and 6, the pin 17 and the pin 18 of the single chip are respectively and electrically connected to at least one input terminal of the PWM wave output control module. In this embodiment, the number of the input ends of the PWM wave output control module electrically connected to the single chip microcomputer is 2, and in other embodiments, the number of the input ends may be 1, 2, 3, or 5, and the like. The PWM wave output control module comprises a first PWM wave output control circuit and a second PWM wave output control circuit. Preferably, the first input end PP0 of the first PWM wave output control circuit is electrically connected to the pin 17 of the single chip microcomputer, and the second input end PP1 of the second PWM wave output control circuit is electrically connected to the pin 18 of the single chip microcomputer. Therefore, the single chip microcomputer can send PWM wave signals to the corresponding 2 input ends of the PWM wave output control module through the 2 output ends, and therefore the duty ratio of the PWM waves output by the first PWM wave output control circuit and the second PWM wave output control circuit is controlled.

Referring to fig. 5, the first PWM output control circuit includes a first transistor Q10, a second transistor Q11, and a first MOS transistor Q15; the PWM wave signal is transmitted to the first MOS transistor Q15 after passing through the first transistor Q10 and the second transistor Q11, one end of the first MOS transistor Q15 is connected to the ground through a first resistor R76, and the other end is connected to the first output end a1 of the first PWM wave output control circuit. Further, in the present embodiment, the PWM wave signal is input through the first input port PP0, the collector of the first transistor Q10 is connected to the base of the second transistor Q11 through the resistor R63, and the collector of the first transistor Q10 is connected to the collector of the second transistor Q11 through the resistor R88; the collector of the second triode Q11 is connected with the +12V _ DRIVER port; the discharge electrode of the second triode Q11 is connected with the collector electrode of the triode Q18, the second triode Q11 is connected with the base electrode of the triode Q18, the discharge electrode of the triode Q18 is grounded, a 16V voltage-stabilizing tube Z6 is connected between the base electrode of the triode Q18 and the discharge electrode in series, the discharge electrode of the second triode Q11 at the rear end is connected with the collector electrode of the triode Q18 and is conveyed backwards, the discharge electrode is connected with a resistor R85 and connected with a diode D20 and a resistor R58 in parallel, the backward output is respectively connected with a resistor R78, a 16V voltage-stabilizing tube Z12 and a capacitor C83 in ground, and the backward output is connected with the first MOS tube Q15 for output. The collector of the first MOS transistor Q15 is connected to the first output terminal a1 of the first PWM wave output control circuit, and the discharge electrode at the other end is connected in series to a R76 ground, and is connected to the POWER port at the first output terminal a1 and a diode D23 is connected in series therein. Therefore, the PWM wave signal is amplified to a 12VPWM wave signal by the first transistor Q10 and the second transistor Q11, and then transmitted to the first MOS transistor Q15 through the resistor R85, the diode D20 and the resistor R58, so as to control the on/off of the first MOS transistor Q15 to ground. The resistor R85 is used for preventing the first MOS transistor Q15 from being conducted by mistake and avoiding being turned on quickly; a diode D20 and a resistor R58 are used to increase the turn-off speed of the first MOS transistor Q15, thereby achieving a faster turn-off characteristic. The circuit configuration of the first PWM wave output control circuit may be another circuit configuration capable of controlling the MOS transistor to be turned on and off and controlling the first output terminal a1 to ground.

Referring to fig. 6, the second PWM output control circuit includes a third transistor Q13, a fourth transistor Q12, and a second MOS transistor Q6; the PWM wave signal is transmitted to the second MOS transistor Q6 after passing through the third transistor Q13 and the fourth transistor Q12, one end of the second MOS transistor Q6 is connected to the ground through a second resistor R117, and the other end is connected to the first output end a2 of the second PWM wave output control circuit. Further, in the present embodiment, the PWM wave signal is input through the second input port PP1, the collector of the third transistor Q13 is connected to the base of the fourth transistor Q12 through the resistor R66, and the collector of the third transistor Q13 is connected to the collector of the fourth transistor Q12 through the resistor R18; the collector of the fourth triode Q12 is connected with the +12V _ DRIVER port; the discharge electrode of the fourth triode Q12 is connected with the collector electrode of the triode Q9, the fourth triode Q12 is connected with the base electrode of the triode Q9, the discharge electrode of the triode Q9 is grounded, a 16V voltage-stabilizing tube Z8 is connected between the base electrode of the triode Q9 and the discharge electrode in series, the discharge electrode of the rear-end fourth triode Q12 is connected with the collector electrode of the triode Q9 and is transmitted backwards, the discharge electrode is connected with a resistor R92 and connected with a diode D21 and a resistor R62 in parallel, the backward output is respectively connected with a resistor R77 and a 16V voltage-stabilizing tube Z13 in ground, and the resistor R59 and a capacitor C76 which are connected with the power supply in series are connected with the second MOS tube Q6 for output. The collector of the second MOS transistor Q6 is connected to the second output terminal a2 of the second PWM wave output control circuit, and the discharge electrode at the other end is connected in series to a R117 ground, and is connected to the POWER port at the second output terminal a2 and in series with a diode D27. Therefore, the PWM wave signal is amplified to a 12VPWM wave signal by the third transistor Q13 and the fourth transistor Q12, and then transmitted to the second MOS transistor Q6 through the resistor R92, the diode D21 and the resistor R62, so as to control the on/off of the second MOS transistor Q6 to ground. The resistor R92 is used for preventing the second MOS transistor Q6 from being conducted by mistake and avoiding being turned on quickly; a diode D21 and a resistor R62 are used to increase the turn-off speed of the second MOS transistor Q6, which achieves faster turn-off characteristics. The circuit configuration of the second PWM wave output control circuit may be another circuit configuration that can control the MOS transistor to open and close and control the second output terminal a2 to ground, and the circuit configuration of the second PWM wave output control circuit is not limited in this embodiment.

Referring to fig. 2, 7 and 8, pins 52 to 58 of the single chip are electrically connected to at least one input terminal of the relay control module, respectively. In this embodiment, the number of the input ends of the relay control module electrically connected to the single chip microcomputer is 7, and in other embodiments, the number of the input ends may be 1, 2, 3, or 5, and the like. The relay control module comprises a Darlington tube and a relay. The model of the Darlington tube is preferably ULQ2003-16PIN, other Darlington tubes with the same or similar functions can be selected, and the skilled person can flexibly select the Darlington tubes according to the needs. Preferably, pin 52 of the single chip microcomputer is electrically connected to pin 7 of the darlington tube, pin 53 of the single chip microcomputer is electrically connected to pin 6 of the darlington tube, pin 54 of the single chip microcomputer is electrically connected to pin 5 of the darlington tube, pin 55 of the single chip microcomputer is electrically connected to pin 4 of the darlington tube, pin 56 of the single chip microcomputer is electrically connected to pin 3 of the darlington tube, pin 57 of the single chip microcomputer is electrically connected to pin 2 of the darlington tube, and pin 58 of the single chip microcomputer is electrically connected to pin 1 of the darlington tube. Therefore, the signal of singlechip output carries out signal isolation and improves the driving capability of signal after 7 input ends input through the darlington pipe to lead to the singlechip to be burnt out when can avoiding the later stage circuit to appear short circuit scheduling problem.

A first motor control terminal of the relay (as shown in fig. 8, pin 1 is a first motor control terminal) is electrically connected to the positive electrode of the strut motor, and a second motor control terminal of the relay (as shown in fig. 8, pin 6 is a second motor control terminal) is electrically connected to the negative electrode of the strut motor. The strut motor in this embodiment is a dc motor. Therefore, the first motor control end and the second motor control end output PWM wave signals to the positive pole and the negative pole of the stay bar motor under the conducting state of the relay, and therefore the stay bar motor is controlled.

Pin 10 of the darlington tube is electrically connected to the positive control end of the relay (as shown in fig. 8, pin 2 is the positive control end), where the positive control end is the input end; the pin 11 is electrically connected to a negative control terminal of the relay, where the negative control terminal is an input terminal (as shown in fig. 8, the pin 10 is a negative control terminal). Therefore, after the output end of the single chip microcomputer inputs a control signal to the input end of the Darlington tube, the Darlington tube can enable the relay to recover the non-conducting state by pulling up the positive control end and the negative control end of the relay.

A first output end A1 of the first PWM wave output control circuit is electrically connected with a first receiving end of the relay; the second output end a2 of the second PWM wave output control circuit is electrically connected to the second receiving end of the relay. The first receiving terminal of relay is the input, and the second receiving terminal of relay is the input. Therefore, when the positive control end and the negative control end of the relay are pulled up to enable the relay to recover the non-conducting state, the positive electrode of the strut motor is directly and electrically connected to the first output end A1 of the first PWM wave output control circuit through the first receiving end of the relay, and the negative electrode of the strut motor is directly and electrically connected to the second output end A2 of the second PWM wave output control circuit through the second receiving end of the relay, so that short circuit of the circuit is achieved.

Referring to fig. 9, a flowchart of a control method for suppressing falling of the tail gate of the automobile according to an embodiment of the present application is shown, where the present application is applied to a driving circuit for suppressing falling of the tail gate of the automobile, and the method includes the following steps:

firstly, a Hall signal acquisition module sends an acquired Hall signal to a single chip microcomputer after filtering processing;

secondly, the single chip microcomputer receives the Hall signal and obtains the current tail gate running speed, and the current tail gate running speed is compared with a preset threshold value in the single chip microcomputer;

the preset threshold is pre-stored in the single chip microcomputer, and the value of the preset threshold can be set by a user.

If the running speed is lower than the preset threshold value, judging that the speed is too low, and controlling a PWM wave output control module by the single chip microcomputer to increase the duty ratio of the current output PWM wave so as to increase the running speed of the tail gate;

if the running speed is equal to the preset threshold value, judging that the speed is normal, and maintaining the duty ratio of the PWM wave currently output by the PWM wave output control module by the singlechip at the moment;

if the running speed is higher than the preset threshold value, the speed is judged to be too high, and at the moment, the single chip microcomputer controls the PWM wave output control module to reduce the duty ratio of the current output PWM wave so as to reduce the running speed of the tail gate;

until the running speed is equal to a preset threshold value, the goal of tail gate deceleration is achieved;

step four, when the duty ratio of the PWM wave output by the PWM wave output control module is reduced to 0, and the running speed is still larger than the preset threshold value;

the singlechip sends a control signal to the Darlington tube; meanwhile, the singlechip sends PWM waves with duty ratios both being full values to a first PWM wave output control circuit and a second PWM wave output control circuit in the PWM wave output control module;

after the darlington tube receives the control signal, 12V voltage is output to the positive control end and the negative control end of the relay through the darlington tube, so that the positive control end and the negative control end of the relay are disconnected, the relay is enabled to be recovered to a non-conduction state, and the relay is enabled to be recovered to the non-conduction state, at the moment, the positive electrode of the strut motor is electrically connected to the first output end A1 of the first PWM wave output control circuit, and the negative electrode of the strut motor is electrically connected to the second output end A2 of the second PWM wave output control circuit;

after the first PWM wave output control circuit and the second PWM wave output control circuit receive the PWM wave with the full duty ratio, the positive pole of the strut motor is conducted and connected to the ground through the first output end A1, and the negative pole of the strut motor is conducted and connected to the ground through the second output end A2.

According to the method, the first output end A1 port of the first PWM wave output control circuit is always open to the ground through the PWM wave with the full duty ratio, the second output end A2 port of the second PWM wave output control circuit is always open to the ground through the PWM wave with the full duty ratio, so that the two ends of the anode and the cathode of the strut motor are in short circuit, and under the condition that the two ends of the strut motor are in short circuit, the faster the strut motor is, the larger the braking force generated by the strut motor is, the slower the strut motor is, the smaller the braking force generated by the strut motor is, and the strut motor can be braked and decelerated due to the characteristic, so that the deceleration target is realized.

After the first PWM wave output control circuit and the second PWM wave output control circuit receive the PWM wave with the full duty ratio, the positive pole of the strut motor is conducted and coupled to the ground through the first output terminal a1, and the negative pole of the strut motor is conducted and coupled to the ground through the second output terminal a2, the method further includes:

the single chip microcomputer sends PWM waves with non-full duty ratio to the first PWM wave output control circuit, and the single chip microcomputer sends PWM waves with full duty ratio to the second PWM wave output control circuit;

when the first PWM wave output control circuit receives the PWM wave with the duty ratio of a non-full value and the second PWM wave output control circuit receives the PWM wave with the duty ratio of a full value, the positive pole of the strut motor is indirectly opened and closed to the ground through the first output end A1, and the negative pole of the strut motor is conducted and connected to the ground through the second output end A2.

Through the method, the port of the first output end A1 of the first PWM wave output control circuit is indirectly opened and closed to the ground through the PWM waves with the non-full duty ratio, the port of the second output end A2 of the second PWM wave output control circuit is always opened to the ground through the PWM waves with the full duty ratio, so that the positive pole of the stay bar motor jumps between the ground and the suspension, the negative pole of the stay bar motor is always opened to the ground, and the duty ratio of the PWM waves input to the first PWM wave output control circuit through the single chip microcomputer can adjust the deceleration amplitude of the stay bar motor.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.