An electric vehicle braking system and method

Abstract

The present invention provides an electric vehicle braking system and method, which relates to the technical field of electric vehicle control, and includes: a base; a brake handle pivotally hinged to the base for driving a mechanical braking device, and a protruding portion is provided at one end of the brake handle close to the hinge point; a switch assembly fixedly arranged at the lower end of the base and forming interference with the protruding portion, and the switch assembly includes: a first switch connected in series to the braking circuit of the electric vehicle drive controller; a second switch connected in series to the braking circuit of the electric vehicle drive controller; an electric vehicle drive controller for respectively controlling the electric vehicle drive controller to enter a first braking state and a second braking state according to the first switch signal and the second switch signal so as to perform braking self-check, and for controlling the operating state of the drive motor. The present invention improves the riding feeling of hill-start and electronic braking, ensures that the driver is safer during the process of driving the whole vehicle; at the same time, it improves the braking reliability, and has the advantages of simple structure and convenient later maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle control, and in particular to an electric vehicle braking system and method. Background Art

[0002] Electric vehicles are a convenient and green means of transportation and have become an important part of many people's lives.

[0003] Most electric vehicles on the market use a common brake light control switch and brake signal switch. In this way, when the brake handle is pulled, the brake light and brake signal are triggered at the same time. Only when the brake handle is released to disconnect the switch, the brake signal will be released. Therefore, when the brake handle is released but the switch is not disconnected, the vehicle cannot be driven by turning the throttle handle. Therefore, starting on a flat road will feel frustrating, and starting on a slope may cause the vehicle to slip, which may be dangerous in serious cases.

[0004] Most of the existing technical solutions lack a self-detection process for electric vehicle brakes, which poses a risk of brake failure; in some technical solutions, there is a power-on detection brake process, and when the detection fails, the user cannot control the start of the electric vehicle, thus causing inconvenience to the user. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides an electric vehicle braking system, comprising:

[0006] A base;

[0007] a brake handle, pivotally hinged to the base, for driving a mechanical brake device, wherein a protrusion is provided at one end of the brake handle close to the hinge point;

[0008] A switch assembly is fixedly mounted at the lower end of the base and interferes with the protrusion, and the switch assembly includes:

[0009] A first switch, connected in series to a brake circuit of an electric vehicle driving controller, for controlling the opening and closing of the brake light and generating a first switch signal;

[0010] A second switch is connected in series to the brake circuit of the electric vehicle driving controller to generate a second switch signal.

[0011] An electric vehicle drive controller is respectively connected to the first switch, the second switch and a drive motor, and is used to control the electric vehicle drive controller to enter a first braking state and a second braking state according to the first switch signal and the second switch signal, so as to perform a brake self-test and control the operating state of the drive motor.

[0012] Preferably, the brake circuit of the electric vehicle drive controller is a high-level brake circuit, and the high-level brake circuit includes:

[0013] A high-level signal input port;

[0014] A first series resistor voltage dividing circuit connected between the high-level signal input port and the ground;

[0015] An NPN-type triode, with the base connected to the voltage dividing node of the first series resistor voltage dividing circuit and the emitter grounded;

[0016] A second series resistor voltage dividing circuit connected between an input voltage and the collector of the NPN-type triode;

[0017] An electric vehicle drive controller includes a brake signal input terminal, and the brake signal input terminal is connected to the voltage dividing node of the second series resistor voltage dividing circuit through a first resistor;

[0018] Preferably, the brake circuit of the electric vehicle drive controller is a low-level brake circuit, and the low-level brake circuit includes:

[0019] A low-level signal input port,

[0020] A diode, with the cathode connected to the low-level signal input port;

[0021] A second resistor connected between an input voltage and the anode of the diode;

[0022] An electric vehicle drive controller includes a brake signal input terminal, and the brake signal input terminal is connected to the anode of the diode through a third resistor;

[0023] Preferably, the brake circuit of the electric vehicle drive controller further includes:

[0024] A battery connected to the electric vehicle drive controller;

[0025] A DC conversion device, with the input terminal connected to the battery, and the positive output terminal connected to the high-level signal input port through the first switch and the second switch;

[0026] A brake light, with one end connected to the first switch and the high-level signal input port, and the other end connected to the negative output terminal of the DC conversion device.

[0027] Preferably, the brake circuit of the electric vehicle drive controller further includes:

[0028] A battery connected to the electric vehicle drive controller;

[0029] A DC conversion device, the input end of which is connected to the battery, and the negative output end is connected to the low-level signal input port through the first switch and the second switch;

[0030] A brake light, one end of which is connected to the first switch and the low-level signal input port, and the other end is connected to the positive output end of the DC conversion device.

[0031] Preferably, a through hole is provided at the position of the protrusion corresponding to the second switch, and a limiting post 4 is fixed in the through hole by a nut to adjust the stroke of the second switch.

[0032] An electric vehicle includes a left brake and a right brake, and the left brake is formed by any one of the above-mentioned electric vehicle brake systems.

[0033] Preferably, the right brake is formed by any one of the above-mentioned electric vehicle brake systems.

[0034] An electric vehicle braking method is applied to the above-mentioned electric vehicle braking device, and includes:

[0035] Step S1, after power-on, successively detect the on-off states of the circuits where the second switch and the first switch are located to obtain a detection result, and generate corresponding motor control instructions according to the detection result to control the operation of the drive motor;

[0036] Step S2, when the drive motor is running, detect the on-off state of the circuit where the first switch is located to obtain a third detection result;

[0037] Step S3, according to the third detection result, detect the on-off state of the circuit where the second switch is located to obtain a fourth detection result;

[0038] Step S4, generate a brake state abnormal warning signal when the fourth detection result indicates that the circuit where the first switch is located is disconnected and the circuit where the second switch is located is conductive, and generate an electronic braking signal when the fourth detection result indicates that the circuits where the first switch and the second switch are located are both conductive.

[0039] Preferably, the step S1 includes:

[0040] Step S11, after power-on, detect the on-off state of the circuit where the second switch is located to generate a first detection result;

[0041] Step S12, according to the first detection result, detect the on-off state of the circuit where the first switch is located to generate a second detection result;

[0042] Step S13, generate a permission start operation signal;

[0043] Step S14: Generate a first motor control instruction when the second detection result indicates that both the circuits where the first switch and the second switch are located are conducting, and generate a second motor control instruction when the second detection result indicates that there is one non-conducting circuit among the circuits where the first switch and the second switch are located.

[0044] The above technical solution has the following advantages or beneficial effects:

[0045] (1) Before driving the motor, detect the circuits where the first switch and the second switch are located respectively, to avoid the driving motor being unable to operate due to the failure of the brake switch;

[0046] (2) During the operation of the driving motor, detect the circuits where the first switch and the second switch are located, and adjust the driving control of the driving motor according to the detection results, improving the riding feeling of hill start and electronic braking, and ensuring the driver is safer during the process of driving the whole vehicle.

[0047] (3) Improve the brake reliability, and at the same time have the advantages of simple structure and convenient later maintenance. Description of the Drawings

[0048] Figure 1 In the preferred embodiment of the present invention, it is the structural schematic diagram of the electric vehicle brake system;

[0049] Figure 2 In the preferred embodiment of the present invention, it is the circuit schematic diagram of the high-level brake circuit;

[0050] Figure 3 In the preferred embodiment of the present invention, it is the circuit schematic diagram of the low-level brake circuit;

[0051] Figure 4 In the preferred embodiment of the present invention, it is the electrical schematic diagram of the low-level brake circuit;

[0052] Figure 5 In the preferred embodiment of the present invention, it is the electrical schematic diagram of the high-level brake circuit;

[0053] Figure 6 In the preferred embodiment of the present invention, it is the flowchart of the electric vehicle brake method;

[0054] Figure 7 In the preferred embodiment of the present invention, it is the sub-flowchart of the electric vehicle brake method;

[0055] Figure 8 In the preferred embodiment of the present invention, it is the control effect diagram of the electric vehicle brake system. Detailed Embodiments

[0056] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment, and other embodiments also belong to the scope of the present invention as long as they conform to the gist of the present invention.

[0057] In a preferred embodiment of the present invention, in view of the above problems existing in the prior art, an electric vehicle braking device is provided as Figure 1 shown, including:

[0058] A base 2;

[0059] A brake handle 3, pivotally hinged to the base 2, used to drive a mechanical brake braking device. A protruding portion 31 is provided at one end of the brake handle 3 close to the hinge point.

[0060] A switch assembly 5, fixedly arranged at the lower end of the base 2 and interfering with the protruding portion 31. The switch assembly 5 includes:

[0061] A first switch S1, connected in series to the brake circuit of the electric vehicle drive controller, used to control the on / off of the brake light and generate a first switch signal;

[0062] A second switch S2, connected in series to the brake circuit of the electric vehicle drive controller, used to generate a second switch signal;

[0063] An electric vehicle drive controller, respectively connected to the first switch, the second switch and a drive motor, used to respectively control the electric vehicle drive controller to enter a first braking state and a second braking state according to the first switch signal and the second switch signal for brake self-check, and to control the operating state of the drive motor.

[0064] Specifically, in this embodiment, the base 2 is fixedly installed on an electric vehicle handle 1. The first switch S1 is arranged above the second switch S2. The first switch S1 and the second switch S2 are respectively connected to the first interface B1 and the second interface B2 of the electric vehicle drive controller 6 through a first switch terminal S11 and a second switch terminal S12.

[0065] Furthermore, the first switch S1 is also connected in series to the brake light circuit. As Figure 8 shown, when the first switch S1 is closed, the brake light circuit is turned on, and at this time the brake light 9 is lit; when the first switch S1 is opened, the brake light circuit is turned off, and at this time the brake light 9 is extinguished.

[0066] In this embodiment, when the brake handle 3 is in the normal state, the protrusion 31 is in contact with both the first switch S1 and the second switch S2. At this time, both the first switch S1 and the second switch S2 are turned off, and the electric vehicle drive controller 6 does not enter the first braking state and the second braking state. When the brake handle 3 is gripped tightly, the protrusion 31 at the other end of the brake handle 3 moves away from the switch assembly 5. The first switch S1 separates from the protrusion 31 first. At this time, the first switch S1 is closed and conducts with the first interface B1 of the electric vehicle drive controller 6. The first switch signal generated by the first switch S1 controls the electric vehicle drive controller 6 to enter the first braking state. At this time, the electric vehicle drive controller 6 controls the drive motor to stop running. When the brake handle 3 is gripped more tightly, the second switch S2 separates from the limit post 4 on the protrusion 31. At this time, the second switch S2 is closed and conducts with the second interface B2 of the electric vehicle drive controller 6. The second switch signal generated by the second switch S2 controls the electric vehicle drive controller 6 to enter the second braking state and exit the first braking state. At this time, the electric vehicle drive controller 6 controls the drive motor to generate braking force to restrict the electric vehicle from moving in the current moving direction, realizing electronic braking.

[0067] Further, the priority of the second braking state is higher than that of the first braking state. When the drive motor enters the second braking state, it exits the first braking state. The purpose of entering the second braking state and exiting the first braking state is that when the brake handle 3 is released and the second braking state is exited, since the mechanical brake is still within the braking stroke, the acceleration handle can be rotated at this time, and then the electric vehicle drive controller 6 is used to control the drive motor to run forward, which can significantly improve the ramp start, that is, prevent slipping.

[0068] In this embodiment, the electric vehicle drive controller 6 has two braking interfaces, namely the first interface B1 and the second interface B2. The first interface B1 is connected to the first switch S1, and the second interface B2 is connected to the second switch S2. The first interface B1 and the second interface B2 are respectively connected to different high-level braking circuits 6A or low-level braking circuits 6B inside the electric vehicle drive controller 6. Both the first interface B1 and the second interface B2 can select one of the two circuits of the high-level braking circuit 6A and the low-level braking circuit 6B. The two circuits can be combined into one circuit and realized through different chip mounting forms. Furthermore, one of them can be selected according to the actual usage situation, which reflects the flexibility of the technical solution. At the same time, such a design makes the peripheral interfaces of the braking function of the electric vehicle drive controller 6 unified, effectively reducing the number of interfaces and being beneficial to cost saving.

[0069] In a preferred embodiment of the present invention, the braking circuit of the electric vehicle drive controller is the high-level braking circuit 6A. As Figure 2 shown, the high-level braking circuit 6A includes:

[0070] A high-level signal input port 6A1, which can be the signal input port of the electric vehicle drive controller 6;

[0071] A first series resistor voltage dividing circuit, connected between the high-level signal input port 6A1 and the ground GND;

[0072] An NPN transistor Q1, with its base connected to the voltage dividing node of the first series resistor voltage dividing circuit and its emitter grounded to GND;

[0073] A second series resistor voltage dividing circuit, connected between an input voltage VCC and the collector of the NPN transistor Q1;

[0074] The electric vehicle drive controller 6 further includes a brake signal input terminal 61, which can be the input port of the microprocessor. The brake signal input terminal 61 is connected to the voltage dividing node 1 of the second series resistor voltage dividing circuit through a first resistor R1.

[0075] Specifically, in this embodiment, the high-level brake circuit 6A is used to input the high-level brake signal into the electric vehicle drive controller 6. Preferably, the high-level brake signal can be a 12V DC signal. The 12V DC signal is input into the high-level brake circuit 6A through the high-level signal input port 6A1 of the electric vehicle drive controller 6. The first series resistor voltage dividing circuit includes a fourth resistor R4 and a fifth resistor R5 connected in series. The second series resistor voltage dividing circuit includes a sixth resistor R6 and a seventh resistor R7 connected in series. The fourth resistor R4 and the fifth resistor R5 divide the 12V DC signal, so that the voltage difference between the base and the emitter of the NPN transistor Q1 satisfies the turn-on voltage. At this time, the collector and the emitter of the NPN transistor Q1 are turned on, and then the input voltage VCC, the sixth resistor R6, the seventh resistor R7 and the ground GND form a loop. By adjusting the resistance values of the sixth resistor R6 and the seventh resistor R7, a low-level signal is input into the brake signal input terminal 61 of the microprocessor. Among them, the function of the first resistor R1 is to prevent the current input into the brake signal input terminal 61 of the microprocessor from being too large, which may cause damage to the brake signal input terminal 61 of the microprocessor, playing a protective role and ensuring the safety of this technical solution.

[0076] In a preferred embodiment, the resistance value of the first resistor R1 is 2.2K ohms, the resistance value of the fourth resistor R4 is 30K ohms, the resistance value of the fifth resistor R5 is 2K ohms, the resistance value of the sixth resistor R6 is 1K ohms, the resistance value of the seventh resistor R7 is 10K ohms, the specification of the NPN transistor Q1 is 2N5551, and the input voltage VCC is 3.3V.

[0077] In a preferred embodiment of the present invention, as Figure 3As shown, the brake circuit of the electric vehicle drive controller is a low-level brake circuit 6B, and the low-level brake circuit 6B includes:

[0078] A low-level signal input port 6B1, and this low-level signal input port 6B1 can be the input port of the electric vehicle drive controller 6;

[0079] A diode D1, with the cathode connected to the low-level signal input port 6B1;

[0080] A second resistor R2, connected between an input voltage VCC and the anode of the diode D1;

[0081] An electric vehicle drive controller 6, including a brake signal input terminal 61, and this brake signal input terminal 61 can be the input port of the microprocessor. The brake signal input terminal 61 is connected to the anode of the diode D1 through a third resistor R3;

[0082] The second switch S2 is connected in series between the low-level signal input port 6B1 and the cathode of the diode D1.

[0083] Specifically, in this embodiment, the low-level brake signal can be a 0V signal. The voltage of the input voltage VCC is divided by the second resistor R2 and the third resistor R3, and directly outputs a low-level signal to the brake signal input terminal 61 of the microprocessor. The function of the diode D1 is to prevent the access of high-level signals, thereby causing damage to the brake signal input terminal 61 of the microprocessor. When a high-level signal is accidentally connected to the low-level signal input port 6B1 of the electric vehicle drive controller 6, the diode D1 cuts off the access of the high-level signal, resulting in the high-level signal being unable to flow into the brake signal input terminal 61 of the microprocessor. Therefore, the brake signal input terminal 61 of the microprocessor is protected, ensuring the safety of this technical solution.

[0084] In a preferred embodiment, the resistance value of the second resistor R2 used is 10K ohms, the resistance value of the third resistor R3 is 2.2K ohms, the specification of the diode D1 is 1N4148, and the input voltage VCC is 3.3V.

[0085] In a preferred embodiment of the present invention, as Figure 5 shown, the brake circuit of the electric vehicle drive controller further includes:

[0086] A battery 8, connected to the electric vehicle drive controller 6;

[0087] A DC conversion device 7, with the input end connected to the battery 8, and the positive output end connected to the high-level signal input port 6A1 through the first switch S1 and the second switch S2;

[0088] A brake light 9, one end is connected to the first switch S1 and the high-level signal input port 6A1, and the other end is connected to the negative output end of the DC conversion device 7.

[0089] Specifically, in this embodiment, the DC conversion device 7 can be a DC converter. The positive pole of the battery 8 is connected to the positive input terminal of the DC converter, and the negative pole of the battery 8 is connected to the negative input terminal of the DC converter. Preferably, the DC voltage output by the positive output terminal of the DC converter is 12V, and the DC voltage output by the negative output terminal of the DC converter is 0V. The voltage output by the battery 8 is converted by the DC converter to provide power for the brake light 9.

[0090] Further, when the brake signal input by the electric vehicle drive controller 6 is a high-level brake signal, one end of the brake light 9 is connected to the first switch S1, and the other end is connected to the negative output end of the DC converter 7.

[0091] In a preferred embodiment of the present invention, as Figure 4 shown, the brake circuit of the electric vehicle drive controller further includes:

[0092] A battery 8, connected to the electric vehicle drive controller 6;

[0093] A DC conversion device 7, the input end is connected to the battery 8, and the negative output end is connected to the low-level signal input port 6B1 through the first switch S1 and the second switch S2;

[0094] A brake light 9, one end is connected to the first switch S1 and the low-level signal input port 6B1, and the other end is connected to the positive output end of the DC conversion device 7.

[0095] Specifically, in this embodiment, when the brake signal input by the electric vehicle drive controller 6 is a low-level brake signal, one end of the brake light 9 is connected to the first switch S1 and the low-level signal input port 6B1, and the other end is connected to the positive input end of the DC converter 7.

[0096] Preferably, the DC converter can be not set, and the battery 8 is directly connected to the electronic brake circuit and the brake light 9. At this time, the resistance values of the fourth resistor R4 and the fifth resistor R5 in the high-level brake circuit 6A are adjusted to meet the turn-on voltage of the NPN-type triode Q1, so that the collector and emitter of the NPN-type triode Q1 are conducted, and a low-level signal can be input to the brake signal input terminal 61 of the microprocessor.

[0097] Further, the first switch S1 includes:

[0098] A first left brake lever switch L-S1 and a first right brake lever switch L-R1. The first left brake lever switch L-S1 and the first right brake lever switch L-R1 are connected in parallel and then electrically connected to the first interface B1 and the brake light 9, both of which are used to control the first braking state of the drive motor.

[0099] Further, the second switch S2 includes:

[0100] A second left brake lever switch L-S2 and a second right brake lever switch L-R2. The second left brake lever switch L-S2 and the second right brake lever switch L-R2 are connected in parallel and then electrically connected to the second interface B2, both of which are used to control the second braking state of the drive motor.

[0101] In a preferred embodiment of the present invention, a through hole is provided at the position of the protruding portion 31 corresponding to the second switch S2, and a limiting column 4 is fixed in the through hole by a nut 10 to adjust the stroke of the second switch S2.

[0102] Specifically, in this embodiment, the limiting column 4 can be a limiting screw. The limiting screw is installed at the lower end of the protruding portion 31 and abuts against the second switch S2. The limiting screw is tightened on the protruding portion 31 by the nut 10 to fix the limiting screw.

[0103] In a preferred embodiment of the present invention, an electric vehicle includes a left brake and a right brake, and the left brake is formed by any one of the above electric vehicle brake devices.

[0104] In a preferred embodiment of the present invention, the right brake is formed by any one of the above electric vehicle brake devices.

[0105] Preferably, it further includes a locking member 11, which penetrates through the switch assembly 5 and is embedded in the base 2, and the switch assembly 5 is fixed to the base 2 through the locking member 11. The locking member 11 can be a locking bolt. By setting the locking bolt, the switch assembly 5 and the base 2 are fixed, making the structural stability of this technical solution higher.

[0106] An electric vehicle braking method is applied to the above electric vehicle braking device, as Figure 6 shown, and includes:

[0107] Step S1, after power-on, sequentially detect the on-off states of the circuits where the second switch and the first switch are located to obtain a detection result, and generate corresponding motor control instructions according to the detection result to control the operation of the drive motor;

[0108] Step S2, when the motor control instruction is valid, detect the on-off state of the circuit where the first switch is located to obtain a third detection result;

[0109] Step S3, detect the on-off state of the circuit where the second switch is located according to the third detection result to obtain a fourth detection result;

[0110] Step S4, when the fourth detection result indicates that the circuit where the first switch is located is disconnected and the circuit where the second switch is located is conducting, generate a brake state abnormal warning signal, and when the fourth detection result indicates that the circuits where the first switch and the second switch are located are both conducting, generate an electronic braking signal.

[0111] Specifically, in this embodiment, after the electric vehicle turns on the ignition switch and completes power-on, the electric vehicle is first subjected to a brake self-check. The user needs to hold the brake handle 3 by hand so that the first switch S1 and the second switch S2 are sequentially in a closed state. Since the distance between the limit post 4 and the second switch S2 is smaller than the distance between the protrusion 31 and the first switch S1, when the user holds the brake handle 3 by hand, the protrusion 31 and the first switch S1 are separated first, and at this time the first switch S1 is closed; subsequently, when the user continues to hold the brake handle 3 tightly, the limit post 4 and the second switch S2 are separated, and at this time the second switch S2 is closed. Therefore, in the normal state, when the second switch S2 is closed, the first switch S1 must have been closed, that is, when it is detected that the circuit where the second switch S2 is located is conducting, the circuit where the first switch S1 is located must have been conducting. When the detection result indicates that the circuit where the second switch S2 is located is conducting and the circuit where the first switch S1 is located is conducting, it indicates that the brake state of the electric vehicle is normal. At this time, an allowable start operation signal is generated, and the user performs a start operation. When the electric vehicle drive controller 6 receives the allowable start operation signal, it can control the drive motor to operate at full power; when the detection result indicates that the circuit where the second switch S2 is located is conducting and the circuit where the first switch S1 is located is not conducting, it indicates that the circuit where the first switch S1 is located is faulty. At this time, the user performs a start operation. When the electric vehicle drive controller 6 receives the allowable start operation signal, it can control the drive motor to operate at a limited power and generate an abnormal warning signal to control the display screen or horn of the electric vehicle to give an alarm; when the detection result indicates that the circuit where the second switch S2 is located is not conducting and the circuit where the first switch S1 is located is conducting, it indicates that the circuit where the second switch S2 is located is faulty. At this time, the electric vehicle drive controller 6 can control the drive motor to operate at a limited power when receiving the allowable start operation signal and generate an abnormal warning signal to control the display screen or horn of the electric vehicle to give an alarm; when the detection result indicates that the circuits where the second switch S2 and the first switch S1 are located are both not conducting, it indicates that the circuits where the first switch S1 and the second switch S2 are located are both faulty. At this time, the electric vehicle drive controller 6 cannot control the drive motor to operate, ensuring the safety of the user.

[0112] When the electric vehicle completes the brake self-check, it enters the normal operation state. When the user holds the brake handle 3, the first switch S1 first separates from the protrusion 31. At this time, the first switch S1 closes, and the electric vehicle drive controller 6 enters the first braking state, and the motor is not driven at this time. When the user continues to hold the brake handle 3 tightly, the second switch S2 separates from the limit post 4. At this time, the second switch S2 closes, and the electric vehicle drive controller 6 exits the first braking state and enters the second braking state. At this time, the electric vehicle drive controller 6 does not drive the drive motor and controls the drive motor to generate braking force to achieve electronic braking.

[0113] When the electric vehicle is in normal operation, first detect the on-off state of the circuit where the first switch S1 is located and obtain the third detection result. When the third detection result indicates that the circuit where the first switch S1 is located is conducting, it indicates that the first switch S1 is closed, and the electric vehicle drive controller 6 enters the first braking state and does not drive the motor. Then, detect the on-off state of the circuit where the second switch S2 is located and obtain the fourth detection result. When the fourth detection result indicates that the circuit where the second switch S2 is located is conducting, the electric vehicle drive controller 6 exits the first braking state and enters the second braking state. At this time, the electric vehicle drive controller 6 does not drive the drive motor and controls the drive motor to rotate in the reverse direction to generate braking force to achieve electronic braking; when the third detection result indicates that the circuit where the first switch S1 is located is open, and at the same time the fourth detection result indicates that the circuit where the second switch S2 is located is conducting, it indicates that there is a fault in the circuit where the first switch S1 is located. At this time, an abnormal warning signal is generated to control the display screen or horn of the electric vehicle to give an alarm. Then, the electric vehicle drive controller 6 enters the second braking state. The electric vehicle drive controller 6 does not drive the drive motor and controls the drive motor to rotate in the reverse direction to generate braking force to achieve electronic braking; when the third detection result indicates that the circuit where the first switch S1 is located is open, and at the same time the fourth detection result indicates that the circuit where the second switch S2 is located is open, the detection starts again.

[0114] During the process of the user releasing the brake handle 3, since the second switch S2 first contacts the limit post 4, the second switch S2 first disconnects. At this time, the electric vehicle drive controller 6 exits the second braking state. At this time, if the electric vehicle is on a steep slope, due to the small amplitude of the release of the brake handle 3 and still within the braking stroke of the mechanical brake, the electric vehicle can be prevented from slipping. At the same time, since the electric vehicle drive controller 6 has exited the first braking state and the second braking state, when receiving the permission to start operation signal, the electric vehicle drive controller 6 can control the drive motor to run forward, enabling the electric vehicle to ride upward from the steep slope and effectively improving the starting feeling of the electric vehicle.

[0115] In a preferred embodiment of the present invention, as Figure 7 shown, step S1 includes:

[0116] Step S11: After power-on, detect the on / off state of the circuit where the second switch is located to generate a first detection result;

[0117] Step S12: Detect the on / off state of the circuit where the first switch is located according to the first detection result to generate a second detection result;

[0118] Step S13: Generate an allowable start operation signal;

[0119] Step S14: Generate a first motor control instruction when the second detection result indicates that both the circuits where the first switch and the second switch are located are conductive, and generate a second motor control instruction when the second detection result indicates that there is a non-conductive path in the circuits where the first switch and the second switch are located.

[0120] Specifically, in this embodiment, the first motor control instruction is to control the drive motor to operate at full power, and the second motor control instruction is to control the drive motor to operate with limited power.

[0121] The above are only preferred embodiments of the present invention, and thus do not limit the implementation manners and protection scope of the present invention. For those skilled in the art, it should be able to realize that all equivalent replacements and obvious changes made by using the content of this specification and the drawings should be included in the protection scope of the present invention.

Claims

1. An electric vehicle braking system, characterized in that, Comprising: A base; A brake handle pivotally hinged to the base for driving a mechanical braking device, and a protrusion is provided at one end of the brake handle near the hinge point; A switch assembly fixedly arranged at the lower end of the base and interfering with the protrusion, and the switch assembly includes: A first switch connected in series to the brake circuit of the electric vehicle drive controller for controlling the on / off of the brake light and generating a first switch signal; A second switch connected in series to the brake circuit of the electric vehicle drive controller for generating a second switch signal; A through hole is provided at the position of the protrusion corresponding to the second switch, and a limit post is fixed in the through hole by a nut for adjusting the stroke of the second switch; An electric vehicle drive controller respectively connected to the first switch, the second switch and a drive motor for respectively controlling the electric vehicle drive controller to enter a first braking state and a second braking state according to the first switch signal and the second switch signal for brake self-check, and controlling the operating state of the drive motor; When the brake handle is gripped, the protrusion moves away from the switch assembly, and the first switch first separates from the protrusion. At this time, the first switch closes and conducts with the first interface of the electric vehicle drive controller; The first switch signal generated by the first switch controls the electric vehicle drive controller to enter the first braking state. At this time, the electric vehicle drive controller controls the drive motor to stop running; When the brake handle is further gripped, the second switch separates from the limit post on the protrusion. At this time, the second switch closes and conducts with the second interface of the electric vehicle drive controller; The second switch signal generated by the second switch controls the electric vehicle drive controller to enter the second braking state and exit the first braking state. At this time, the electric vehicle drive controller controls the drive motor to generate a braking force to limit the movement of the electric vehicle along the current movement direction to achieve electronic braking.

2. The electric vehicle braking system according to claim 1, characterized in that, The brake circuit of the electric vehicle drive controller is a high-level brake circuit, and the high-level brake circuit includes: A high-level signal input port; A first series resistor voltage dividing circuit connected between the high-level signal input port and the ground; An NPN-type triode with the base connected to the voltage dividing node of the first series resistor voltage dividing circuit and the emitter grounded; A second series resistor voltage dividing circuit connected between an input voltage and the collector of the NPN-type triode; A brake signal input terminal, and the brake signal input terminal is connected to the voltage dividing node of the second series resistor voltage dividing circuit through a first resistor.

3. The electric vehicle braking system according to claim 1, characterized in that, The brake circuit of the electric vehicle drive controller is a low-level brake circuit, and the low-level brake circuit includes: A low-level signal input port; A diode with the cathode connected to the low-level signal input port; A second resistor connected between an input voltage and the anode of the diode; A brake signal input terminal connected to the anode of the diode through a third resistor.

4. The electric vehicle braking system according to claim 2, characterized in that, The brake circuit of the electric vehicle drive controller further includes: A battery connected to the electric vehicle drive controller; A DC conversion device, the input end of which is connected to the battery, and the positive output end is connected to the high-level signal input port through the first switch and the second switch; A brake light, one end of which is connected to the first switch and the high-level signal input port, and the other end is connected to the negative output end of the DC conversion device.

5. The electric vehicle braking system according to claim 3, wherein, The brake circuit of the electric vehicle drive controller further includes: A battery, which is connected to the electric vehicle drive controller; A DC conversion device, the input end of which is connected to the battery, and the negative output end is connected to the low-level signal input port through the first switch and the second switch; A brake light, one end of which is connected to the first switch and the low-level signal input port, and the other end is connected to the positive output end of the DC conversion device.

6. An electric vehicle, comprising a left brake and a right brake, characterized in that, The left brake is formed by the electric vehicle brake system according to any one of claims 1-5.

7. The electric vehicle according to claim 6, characterized in that, The right brake is formed by the electric vehicle brake system according to any one of claims 1-5.

8. An electric vehicle braking method, applied to the electric vehicle braking system according to any one of claims 1-5, characterized in that, It includes: Step S1: After power-on, successively detect the on / off states of the circuits where the second switch and the first switch are located to obtain a detection result, and generate corresponding motor control instructions according to the detection result to control the operation of the drive motor; Step S2: When the motor control instruction is valid, detect the on / off state of the circuit where the first switch is located to obtain a third detection result; Step S3: Detect the on / off state of the circuit where the second switch is located according to the third detection result to obtain a fourth detection result; Step S4: Generate a brake state abnormal warning signal when the fourth detection result indicates that the circuit where the first switch is located is disconnected and the circuit where the second switch is located is conductive, and generate an electronic braking signal when the fourth detection result indicates that the circuits where the first switch and the second switch are located are both conductive.

9. The electric vehicle braking method according to claim 8, wherein The step S1 includes: Step S11: After power-on, detect the on / off state of the circuit where the second switch is located to generate a first detection result; Step S12: Detect the on / off state of the circuit where the first switch is located according to the first detection result to generate a second detection result; Step S13: Generate a permission start operation signal; Step S14: Generate a first motor control instruction when the second detection result indicates that the circuits where the first switch and the second switch are located are both conductive, and generate a second motor control instruction when the second detection result indicates that there is a non-conductive path in the circuits where the first switch and the second switch are located.

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