Safety brake control circuit of electric automobile

Abstract

The utility model relates to the technical field of automobile braking, and discloses a safe braking control circuit of an electric automobile, which is good and reliable in braking control effect and comprises a braking input module (110), a signal processing module (120), a main control module (140) and a switch module (150), the braking input module (110) is used for receiving an input braking signal, the signal processing module (120) is used for receiving the processed braking signal, and the switch module (150) is used for controlling the braking input module (110) and the signal processing module (120). A PWM pulse signal is output according to the input brake signal; the switch module (150) is used for receiving a PWM pulse signal, one end of the switch module (150) is connected with one end of the vacuum pump (M), and the main control module (140) adjusts the duty ratio of the PWM pulse signal according to the brake signal so as to control the rotating state of the vacuum pump (M).

Description

Technical Field

[0001] The utility model relates to the technical field of automobile braking, and more specifically to a safety braking control circuit of an electric vehicle. Background Art

[0002] At present, the domestic vacuum pump controller is relatively simple in terms of technology, with low safety and reliability. There are problems such as not stopping and not starting during use. When the power input end is subjected to voltage shock, the components may be burned. In harsh environments, the start point and stop point deviate from the set value, causing the vacuum pump to start frequently or not stop, which greatly consumes the service life of the vacuum pump.

[0003] However, it takes 7s-9s to start the vacuum pump. Its working characteristics are very mechanical and simple, and its control accuracy is low. It cannot detect the working status of the vacuum pump. In addition, the electric pressure switch has low sensitivity and is very prone to failure under harsh external environments. Its safety and stability are very low. For example, when an electric vehicle is driving at high speed, the relay that controls the on / off of the electric vacuum pump fails and the vacuum pump cannot be enabled normally. This may cause the driver to be unable to step on the brake pedal at a wide angle, resulting in the vehicle failing to achieve the expected deceleration. Utility Model Content

[0004] The technical problem to be solved by the utility model is that, in view of the defect in the prior art that when an electric vehicle is running at high speed, the relay controlling the on / off of the electric vacuum pump fails and the vacuum pump cannot be enabled normally, which causes the driver to be unable to step on the brake pedal at a wide opening, making it impossible for the vehicle to achieve the expected deceleration. A safety brake control circuit for an electric vehicle with better and reliable control braking effect is provided.

[0005] The technical solution adopted by the utility model to solve the technical problem is to construct a safety brake control circuit of an electric vehicle, which has:

[0006] A brake input module is configured in the control circuit and is used to receive an input brake signal;

[0007] A signal processing module, one input end of which is connected to the output end of the brake input module, for receiving the brake signal and performing comparison processing on the brake signal;

[0008] A main control module, whose signal input end is coupled to the output end of the signal processing module, is used to receive the processed braking signal and output a PWM pulse signal according to the input braking signal;

[0009] A switch module, whose input end is connected to the output end of the main control module, is used to receive the PWM pulse signal.

[0010] One end of the switch module is connected to one end of the vacuum pump.

[0011] The main control module adjusts the duty cycle of the PWM pulse signal according to the brake signal to control the rotation state of the vacuum pump.

[0012] In some embodiments, the brake input module at least includes a first resistor and a first transistor.

[0013] One end of the first resistor is used to receive the input braking signal.

[0014] The base of the first transistor is connected to the other end of the first resistor.

[0015] The collector of the first transistor is connected to an input terminal of the signal processing module.

[0016] The emitter of the first transistor is connected to the common end.

[0017] In some embodiments, the signal processing module includes a first comparator, a signal processing controller and a second transistor.

[0018] The non-inverting terminal of the first comparator is connected to the collector of the first transistor,

[0019] The inverting terminal of the first comparator is connected to the 6.2V power supply terminal through the sixth resistor and the seventh resistor.

[0020] The input end of the signal processing controller is connected to the output end of the first comparator,

[0021] The base of the second transistor is connected to the output end of the signal processing controller.

[0022] The collector of the second transistor is coupled to the signal input terminal of the main control module.

[0023] The emitter of the second transistor is connected to the common terminal.

[0024] In some embodiments, the main control module includes a main controller,

[0025] The signal input terminal of the main controller is coupled to the collector of the second transistor.

[0026] The signal output terminal of the main controller is connected to the input terminal of the switch module.

[0027] In some embodiments, the switch module includes a MOS tube.

[0028] The gate of the MOS tube is connected to the signal output terminal of the main controller.

[0029] The drain of the MOS tube is connected to one end of the vacuum pump.

[0030] The source of the MOS tube is connected to the common end.

[0031] In some embodiments, a third comparator is further included, wherein the non-inverting terminal of the third comparator is connected to the reference voltage signal terminal.

[0032] The inverting terminal of the third comparator is connected to the source of the MOS tube.

[0033] The output terminal of the third comparator is connected to a signal input terminal of the main controller.

[0034] In some embodiments, the first transistor and the second transistor are selected as NPN transistors.

[0035] The MOS tube is selected as an N-channel MOS tube.

[0036] In some embodiments, a low voltage protection module is further included, one end of which is connected to the 6.2V power supply terminal through a fourth resistor.

[0037] The other end of the low voltage protection module is connected to the 36V power supply end through the twelfth resistor and the thirteenth resistor.

[0038] The output end of the low voltage protection module is connected to the other input end of the signal processing module.

[0039] In some embodiments, the low voltage protection module includes a second comparator,

[0040] The inverting terminal of the second comparator is connected to the 6.2V power supply terminal through the fourth resistor,

[0041] The non-inverting terminal of the second comparator is connected to the 36V power supply terminal through the twelfth resistor and the thirteenth resistor.

[0042] The output terminal of the second comparator is connected to the base of the third transistor.

[0043] The collector of the third transistor is connected to the other input end of the signal processing module.

[0044] The emitter of the third transistor is connected to the common end.

[0045] In the safety brake control circuit of the electric vehicle described in the utility model, it includes a brake input module for receiving an input brake signal, a signal processing module, a main control module and a switch module, wherein the main control module can adjust the duty cycle of the PWM pulse signal according to the input brake signal (such as 100%→50% or 100%→30%...) to control the rotation state of the vacuum pump (such as speed reduction, shutdown), which can effectively control the working state of the vacuum pump. Compared with the prior art, the duty cycle of the output PWM pulse signal is adjusted by analyzing the brake signal to achieve effective control of the speed / start and stop of the electric vacuum pump, which can effectively solve the problem that the prior art only uses relays to control the opening / closing of the electric vacuum pump. When the relay response is delayed or fails, the vacuum pump cannot be enabled normally, which may cause the driver to be unable to step on the brake pedal at a wide opening, resulting in the vehicle failing to achieve the expected deceleration. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0047] Figure 1 The utility model provides a circuit principle diagram of an embodiment of a safety brake control circuit for an electric vehicle. DETAILED DESCRIPTION

[0048] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0049] like Figure 1 As shown, in the first embodiment of the safety brake control circuit of the electric vehicle of the utility model, the safety brake control circuit 100 of the electric vehicle includes a brake input module 110, a signal processing module 120, a low voltage protection module 130, a main control module 140 and a switch module 150;

[0050] The brake input module 110 is used to receive a brake signal generated when the driver steps on the brake pedal;

[0051] The signal processing module 120 is used to receive the braking signal, compare and amplify the braking signal, and then output the processed braking signal to the main control module 140;

[0052] The low voltage protection module 130 is used to obtain two signals (one is 36V and the other is 6.2V). After voltage division, the two signals are input into two signal terminals of the low voltage protection module 130 respectively, and then the two signals are analyzed and compared, and then the control level (high level or low level) is output;

[0053] The main control module 140 is the core of the control circuit, and has the functions of calculation, signal processing, outputting PWM pulse signals and adjusting the duty cycle of PWM pulse signals;

[0054] The switch module 150 functions as a switch, and its on state is controlled by an input PWM pulse signal to control the rotation state of the vacuum pump M (eg, low speed, start / stop).

[0055] Specifically, the brake input module 110 is configured in the control circuit, and is used to receive a brake signal generated when the driver steps on the brake pedal, and output the brake signal to the signal processing module 120;

[0056] An input end of the signal processing module 120 is connected to the output end of the brake input module 110 to receive the brake signal.

[0057] Another input terminal of the signal processing module 120 is connected to the 6.2V power supply terminal. After the 6.2V voltage is divided, the signal processing module 120 uses it as a voltage reference.

[0058] The signal processing module 120 compares the input braking signal with the voltage reference, amplifies the electrical signal output after the comparison, and outputs the processed braking signal to the main control module 140;

[0059] The signal input end of the main control module 140 is coupled to the output end of the signal processing module 120, and is used to receive the processed brake signal, and perform calculation, analysis and processing according to the input brake signal, and then output the PWM pulse signal to the switch module 150;

[0060] The input end of the switch module 150 is connected to the output end of the main control module 140 to receive the PWM pulse signal.

[0061] One end of the switch module 150 is connected to one end of the vacuum pump M.

[0062] Specifically, the main control module 140 analyzes and processes the input brake signal (such as analyzing the force with which the brake pedal is stepped on), and then adjusts the duty cycle of the PWM pulse signal according to the force with which the brake pedal is stepped on (such as 100%→80%, 100%→50%, 100%→30%, 100%→10%, 100%→0%...) to control the rotation state of the vacuum pump M (such as low speed, start / stop).

[0063] By using the present technical solution, the main control module 140 analyzes the brake signal and adjusts the duty cycle of the output PWM pulse signal to achieve effective control of the speed / start / stop of the electric vacuum pump. This can effectively solve the problem in the prior art of using relays to control the on / off of the electric vacuum pump. When the relay response is delayed or fails, the vacuum pump cannot be enabled normally, which may cause the driver to be unable to step on the brake pedal at a wide opening, resulting in the vehicle being unable to achieve the expected deceleration.

[0064] In some implementations, in order to ensure the reliability of obtaining the braking signal, a first resistor R101 and a first transistor Q101 may be provided in the braking input module 110.

[0065] The resistance value of the first resistor R101 can be selected as 430Ω, and the first transistor Q101 is selected as an NPN transistor, which has a switch function;

[0066] Specifically, one end of the first resistor R101 is used to receive an input braking signal.

[0067] The base of the first transistor Q101 is connected to the other end of the first resistor R101.

[0068] The base of the first transistor Q101 is also connected to one end of the third capacitor C103.

[0069] The collector of the first transistor Q101 is connected to the anode of the first diode D101.

[0070] The cathode of the first diode D101 is connected to an input terminal of the signal processing module 120.

[0071] The emitter of the first transistor Q101 and the other end of the third capacitor C103 are connected to the common end.

[0072] It can be understood that the levels of the anode and cathode of the first diode D101 serve as input signals of the signal processing module 120. When the anode level of the first diode D101 is higher than the cathode level, it indicates that there is a brake signal input to the brake pedal, otherwise there is no brake signal input.

[0073] In some implementations, in order to improve the reliability of the brake signal processing, a first comparator A101, a signal processing controller U101 and a second transistor Q102 may be provided in the signal processing module 120.

[0074] The first comparator A101 has the function of signal comparison.

[0075] The signal processing controller U101 has the function of signal analysis and amplification.

[0076] The second transistor Q102 is selected as an NPN transistor, which has the function of a switch;

[0077] Specifically, the in-phase terminal (corresponding to pin 5) of the first comparator A101 is connected to the collector of the first transistor Q101 through the third resistor R103 and the first diode D101 connected in series.

[0078] The cathode of the first diode D101 is connected to the collector of the first transistor Q101.

[0079] The inverting terminal (corresponding to pin 4) of the first comparator A101 is connected to the 6.2V power supply terminal through the sixth resistor R106 and the seventh resistor R107. The 6.2V voltage is divided by the sixth resistor R106 and the seventh resistor R107 and input to the inverting terminal (corresponding to pin 4) of the first comparator A101 as a reference signal.

[0080] The input terminal (corresponding to pin 1) of the signal processing controller U101 is connected to the output terminal (corresponding to pin 6) of the first comparator A101.

[0081] The base of the second transistor Q102 is connected to the output end (corresponding to pin 3) of the signal processing controller U101 through the fifteenth resistor R115.

[0082] The collector of the second transistor Q102 is coupled to the signal input terminal of the main control module 140.

[0083] The emitter of the second transistor Q102 is connected to the common terminal.

[0084] When the electrical signal output by the signal processing controller U101 is at a high level, the second transistor Q102 is controlled to be turned on, and the braking signal is output to the main control module 140 via the second transistor Q102.

[0085] In some embodiments, in order to improve the stability of the working state control of the vacuum pump M, a main controller U102 may be provided in the main control module 140, which has the functions of signal processing, outputting PWM pulse signals and adjusting the duty cycle;

[0086] The signal input terminal (corresponding to pin 7) of the main controller U102 is connected to the collector of the second transistor Q102 through the seventeenth resistor R114.

[0087] The signal output terminal (corresponding to pin 19) of the main controller U102 is connected to the input terminal of the switch module 150 .

[0088] When the second transistor Q102 is controlled to be turned on, the potential of the collector of the second transistor Q102 is set to a low level, the potential of the signal input end (corresponding to pin 7) of the main controller U102 is at a low level, and the main controller U102 adjusts the duty cycle of the PWM pulse signal according to the level state of pin 7.

[0089] In some implementations, in order to improve the stability of the working state control of the vacuum pump M, a MOS tube VT101 may be provided in the switch module 150, which is selected as an N-channel MOS tube and has a switch function;

[0090] Specifically, the gate of the MOS tube VT101 is connected to the signal output terminal of the main controller U102 through the eighteenth resistor R118.

[0091] The drain of MOS tube VT101 is connected to one end of vacuum pump M.

[0092] The source of MOS tube VT101 is connected to the common terminal.

[0093] The PWM pulse signal output by the main controller U102 is input into the MOS tube VT101 via the eighteenth resistor R118 to control the switch state of the MOS tube VT101, thereby controlling the working state of the vacuum pump M.

[0094] In some implementations, in order to improve the performance of the control circuit, a third comparator A103 may be provided in the control circuit, which has a signal comparison function.

[0095] Specifically, the in-phase terminal (corresponding to pin 7) of the third comparator A103 is connected to the reference voltage signal terminal (corresponding to pin 8) through the twenty-third resistor R123.

[0096] The inverting terminal (corresponding to pin 8) of the third comparator A103 is connected to the source of the MOS tube VT101 through the nineteenth resistor R119, and is used to obtain the current signal flowing through the MOS tube VT101, compare the current signal with the reference voltage signal, and output a level signal according to the comparison result.

[0097] The output terminal (corresponding to pin 9) of the third comparator A103 and the twenty-fifth resistor R125 are connected to a signal input terminal (corresponding to pin 19) of the main controller U102.

[0098] The main controller U102 adjusts the duty cycle of the PWM pulse signal input to the gate of the MOS tube VT101 according to the input level signal, thereby controlling the conduction state of the MOS tube VT101.

[0099] In some embodiments, in order to improve the performance of the control circuit, a low voltage protection module 130 may be provided in the control circuit, wherein one end of the low voltage protection module 130 is connected to the 6.2V power supply terminal through a fourth resistor R104.

[0100] The other end of the low voltage protection module 130 is connected to the 36V power supply terminal through the twelfth resistor R112 and the thirteenth resistor R113.

[0101] An output terminal of the low voltage protection module 130 is connected to another input terminal of the signal processing module 120 .

[0102] The low voltage protection module 130 includes a second comparator A102.

[0103] The inverting terminal (corresponding to pin 2) of the second comparator A102 is connected to the 6.2V power supply terminal through the fourth resistor R104.

[0104] The in-phase terminal (corresponding to pin 3) of the second comparator A102 is connected to the 36V power supply terminal through the twelfth resistor R112 and the thirteenth resistor R113.

[0105] The output terminal of the second comparator A102 (corresponding to pin 1) is connected to the base of the third transistor Q103.

[0106] The collector of the third transistor Q103 is connected to another input terminal (corresponding to pin 2) of the signal processing controller U101 (belonging to the signal processing module 120).

[0107] The emitter of the third transistor Q103 is connected to the common terminal.

[0108] When the potential of the in-phase terminal (corresponding to pin 3) of the second comparator A102 is higher than that of the inverting terminal (corresponding to pin 2), its output is a high-level signal, and the third transistor Q103 is controlled to be turned on, indicating that the voltage signal is normal.

[0109] When the potential of the in-phase terminal (corresponding to pin 3) of the second comparator A102 is lower than that of the inverting terminal (corresponding to pin 2), its output is a low-level signal, the third transistor Q103 is cut off, and pin 2 of the signal processing controller U101 is high level.

[0110] Specifically, when braking, the braking signal provides a base current to the first transistor Q101 through the first resistor R101, and the first transistor Q101 is controlled to be turned on. The braking signal is output to the 5th pin of the first comparator A101 through the first diode D101. The level of the in-phase end (corresponding to the 5th pin) of the first comparator A101 is higher than the level of the inverting end (corresponding to the 4th pin), and its output is a high level. The second transistor Q102 is controlled to be turned on, and the 7th pin of the main controller U102 is a low level. The main controller U102 can adjust the duty cycle of the PWM pulse signal according to the level state of the 7th pin to control the working state of the vacuum pump M (such as deceleration, start, stop).

[0111] The embodiments of the utility model are described above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the utility model, ordinary technicians in this field can also make many forms without departing from the scope of protection of the utility model and the claims, which all fall within the protection of the utility model.

Claims

1. A safety brake control circuit for an electric vehicle, characterized in that: have: A brake input module is configured in the control circuit and is used to receive an input brake signal; A signal processing module, one input end of which is connected to the output end of the brake input module, for receiving the brake signal and performing comparison processing on the brake signal; A main control module, whose signal input end is coupled to the output end of the signal processing module, is used to receive the processed braking signal and output a PWM pulse signal according to the input braking signal; A switch module, whose input end is connected to the output end of the main control module, is used to receive the PWM pulse signal. One end of the switch module is connected to one end of the vacuum pump. The main control module adjusts the duty cycle of the PWM pulse signal according to the brake signal to control the rotation state of the vacuum pump.

2. The safety brake control circuit of an electric vehicle according to claim 1, characterized in that: The brake input module at least includes a first resistor and a first transistor. One end of the first resistor is used to receive the input braking signal. The base of the first transistor is connected to the other end of the first resistor. The collector of the first transistor is connected to an input terminal of the signal processing module. The emitter of the first transistor is connected to the common end.

3. The safety brake control circuit of the electric vehicle according to claim 2, characterized in that: The signal processing module includes a first comparator, a signal processing controller and a second triode. The non-inverting terminal of the first comparator is connected to the collector of the first transistor, The inverting terminal of the first comparator is connected to the 6.2V power supply terminal through the sixth resistor and the seventh resistor. The input end of the signal processing controller is connected to the output end of the first comparator, The base of the second transistor is connected to the output end of the signal processing controller. The collector of the second transistor is coupled to the signal input terminal of the main control module. The emitter of the second transistor is connected to the common terminal.

4. The safety brake control circuit of the electric vehicle according to claim 3, characterized in that: The main control module includes a main controller, The signal input terminal of the main controller is coupled to the collector of the second transistor. The signal output terminal of the main controller is connected to the input terminal of the switch module.

5. The safety brake control circuit of the electric vehicle according to claim 4, characterized in that: The switch module includes a MOS tube. The gate of the MOS tube is connected to the signal output terminal of the main controller. The drain of the MOS tube is connected to one end of the vacuum pump. The source of the MOS tube is connected to the common end.

6. The safety brake control circuit of the electric vehicle according to claim 5, characterized in that: It also includes a third comparator, wherein the non-inverting terminal of the third comparator is connected to the reference voltage signal terminal, The inverting terminal of the third comparator is connected to the source of the MOS tube. The output terminal of the third comparator is connected to a signal input terminal of the main controller.

7. The safety brake control circuit of the electric vehicle according to claim 5, characterized in that: The first transistor and the second transistor are selected as NPN transistors, The MOS tube is selected as an N-channel MOS tube.

8. The safety brake control circuit of the electric vehicle according to claim 3, characterized in that: It also includes a low voltage protection module, one end of which is connected to the 6.2V power supply terminal through a fourth resistor. The other end of the low voltage protection module is connected to the 36V power supply end through the twelfth resistor and the thirteenth resistor. The output end of the low voltage protection module is connected to the other input end of the signal processing module.

9. The safety brake control circuit of the electric vehicle according to claim 8, characterized in that: The low voltage protection module includes a second comparator, The inverting terminal of the second comparator is connected to the 6.2V power supply terminal through the fourth resistor, The non-inverting terminal of the second comparator is connected to the 36V power supply terminal through the twelfth resistor and the thirteenth resistor. The output terminal of the second comparator is connected to the base of the third transistor. The collector of the third transistor is connected to the other input end of the signal processing module, and the emitter of the third transistor is connected to the common end.

Images