Pump motor driving circuit of redundant brake unit

Abstract

The utility model relates to a pump motor drive circuit of a redundant brake unit. The pump motor drive circuit comprises a first switch unit, a second switch unit, a third switch unit, a first voltage sampling unit and a first current sampling unit. The three switch units connected in series are arranged, the first switch unit and the second switch unit are used for cooperatively controlling starting and stopping of the pump motor B1, and the third switch unit is used for preventing circuit damage caused by reverse connection of a power source. By arranging a first voltage sampling unit and a first current sampling unit, an external voltage acquisition device acquires the voltage of the positive electrode of the power supply input end of a pump motor B1 through the first voltage sampling unit, and an external current acquisition device acquires the working current of the pump motor B1 through the first current sampling unit; an external control system or device can conveniently represent or calculate the rotating speed of the pump motor B1 according to the voltage of the positive electrode of the power input end of the pump motor B1 and the working current; compared with the prior art, the cost is lower.

Description

Technical Field

[0001] The utility model relates to the technical field of pump motor driving, in particular to a pump motor driving circuit of a redundant braking unit. Background Art

[0002] The redundant braking unit (RBU) is a backup component for the integrated brake control unit. To meet vehicle safety requirements, L3 autonomous vehicles and above require an RBU. The pump motor in the RBU is required to increase oil pump pressure on demand. Typically, the pump motor drive circuit uses a half-bridge driver consisting of upper and lower MOSFETs. While common half-bridge driver circuits can achieve motor drive control, they suffer from a low functional safety rating. Furthermore, motor speed control requires current speed information, requiring the addition of a position sensor, which results in high costs. Utility Model Content

[0003] In order to solve the technical problems in the prior art that motor speed control requires obtaining current speed information, adding a position sensor, and resulting in high costs, the utility model provides a pump motor drive circuit with a redundant brake unit.

[0004] The technical solution of the utility model to solve the above technical problems is as follows:

[0005] A pump motor driving circuit of a redundant braking unit includes a first switch unit, a second switch unit, a third switch unit, a first voltage sampling unit, and a first current sampling unit;

[0006] One end of the first switch unit is connected to a power supply, a controlled end of the first switch unit is used to connect to a signal output end of a motor driver chip, and the other end of the first switch unit is respectively connected to the signal output end of the motor driver chip, one end of the second switch unit, and a positive electrode of a power input end of the pump motor;

[0007] The controlled end of the second switch unit is used to connect to the signal output end of the motor driver chip, the other end of the second switch unit is respectively connected to the signal output end of the motor driver chip and one end of the third switch unit, the controlled end of the third switch unit is used to connect to the signal output end of the motor driver chip, and the other end of the third switch unit is grounded;

[0008] The positive pole of the power input end of the pump motor is connected to the external voltage acquisition device through the first voltage sampling unit, and the negative pole of the power input end of the pump motor is grounded through the first current sampling unit. The first current sampling unit is used to connect to the external current acquisition device.

[0009] The beneficial effects of the present utility model are as follows: by setting three switch units in series, and using the first switch unit and the second switch unit to collaboratively control the start and stop of the pump motor B1, and using the third switch unit to prevent circuit damage caused by reverse power supply; when the first switch unit is turned on, the second switch unit is turned off and the third switch unit is turned on, the pump motor B1 is powered on and started; when the first switch unit is turned off, the second switch unit is turned on and the third switch unit is turned on, the pump motor B1 is powered off; when the power supply is reversed, one end of the first switch unit is grounded or connected to the negative pole of the power supply, the other end of the third switch unit is connected to the positive pole of the power supply, the voltage at the other end of the third switch unit is greater than the voltage at the controlled end, the third switch unit is disconnected, and the entire circuit is powered off, thereby preventing circuit damage caused by reverse power supply. At the same time, by setting up a first voltage sampling unit and a first current sampling unit, the external voltage acquisition device can collect the voltage of the positive pole of the power input terminal of the pump motor B1 through the first voltage sampling unit, and the external current acquisition device can collect the working current of the pump motor B1 through the first current sampling unit, thereby facilitating the external control system or device to characterize or calculate the speed of the pump motor B1 according to the voltage of the positive pole of the power input terminal of the pump motor B1 and the working current. Compared with the prior art of setting a speed sensor to monitor the speed of the pump motor B1, the cost of the utility model is lower.

[0010] On the basis of the above technical solution, the present invention can also be improved as follows.

[0011] Furthermore, the first switch unit includes a MOS tube Q1, a resistor R3 and a resistor R4, the drain of the MOS tube Q1 is connected to the power supply, the gate of the MOS tube Q1 is connected to one end of the resistor R3, the other end of the resistor R3 is used to connect to the signal output end of the motor driver chip, the source of the MOS tube Q1 is respectively connected to one end of the resistor R4, one end of the second switch unit and the positive electrode of the power input end of the pump motor, and the other end of the resistor R4 is used to connect to the signal output end of the motor driver chip.

[0012] Furthermore, the second switch unit includes a MOS tube Q2, a resistor R5, and a resistor R6. The drain of the MOS tube Q2 is connected to the source of the MOS tube Q1, the gate of the MOS tube Q2 is connected to one end of the resistor R5, and the other end of the resistor R5 is used to connect to the signal output end of the motor driver chip. The source of the MOS tube Q2 is respectively connected to one end of the resistor R6 and one end of the third switch unit. The other end of the resistor R6 is used to connect to the signal output end of the motor driver chip.

[0013] Furthermore, the third switching unit includes a MOS transistor Q3 and a resistor R7, the source of the MOS transistor Q3 is connected to the source of the MOS transistor Q2, the gate of the MOS transistor Q3 is connected to one end of the resistor R7, the other end of the resistor R7 is used to connect to the signal output end of the motor drive chip, and the drain of the MOS transistor Q3 is grounded.

[0014] Furthermore, the first voltage sampling unit includes a resistor R8 and a resistor R9, one end of the resistor R8 is connected to the positive pole of the power input end of the pump motor, the other end of the resistor R8 is connected to one end of the resistor R9, the other end of the resistor R9 is grounded, and one end of the resistor R9 is used to connect to the external voltage acquisition device.

[0015] Furthermore, the first current sampling unit includes a resistor R2, one end of the resistor R2 is connected to the negative pole of the power input end of the pump motor, the other end of the resistor R2 is grounded, and one end and the other end of the resistor R2 are both used to connect to the external current collection device.

[0016] Furthermore, a second current sampling unit is included, which includes a resistor R1, one end of the resistor R1 is connected to the source of the MOS transistor Q1, and the other end of the resistor R1 is connected to the drain of the MOS transistor Q2, and one end and the other end of the resistor R1 are both used to connect to the external current collection device.

[0017] The beneficial effect of adopting the above further solution is that, by providing the second current sampling unit, it is convenient to collect the current of the first switching unit.

[0018] Furthermore, a second voltage sampling unit is included, which includes a resistor R10 and a resistor R11. One end of the resistor R10 is connected to the source of the MOS tube Q3, the other end of the resistor R10 is connected to one end of the resistor R11, the other end of the resistor R11 is grounded, and one end of the resistor R11 is used to connect to the external voltage collection device.

[0019] The beneficial effect of adopting the above further solution is that by providing a second voltage sampling unit, it is convenient to collect the voltage at one end of the third switch unit, and the switching state of the MOS tube Q3 is monitored by the voltage collected by the second voltage sampling unit, and the switching state of the MOS tube Q2 is monitored in combination with the first voltage sampling unit.

[0020] Furthermore, a filtering unit is included. The filtering unit includes a capacitor C1. The positive electrode of the capacitor C1 is connected to the drain of the MOS transistor Q1, and the negative electrode of the capacitor C1 is connected to the source of the MOS transistor Q2.

[0021] The beneficial effect of adopting the above further solution is that by providing a filtering unit, the capacitor C1 can be used to store energy and perform voltage stabilization filtering on the driving circuit of the pump motor B1, thereby reducing the negative impact of the pump motor B1 on the circuit during operation.

[0022] In order to solve the above technical problems, the present invention also provides an automobile motor drive device, the specific technical contents of which are as follows:

[0023] An automobile electric motor drive device comprises the pump motor drive circuit of the redundant brake unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0026] like Figure 1 As shown, this embodiment provides a pump motor driving circuit of a redundant braking unit, including a first switch unit, a second switch unit, a third switch unit, a first voltage sampling unit, a first current sampling unit, a second current sampling unit, a second voltage sampling unit and a filtering unit;

[0027] One end of the first switch unit is connected to a power supply, a controlled end of the first switch unit is used to connect to a signal output end of a motor driver chip, and the other end of the first switch unit is respectively connected to the signal output end of the motor driver chip, one end of the second switch unit, and a positive electrode of a power input end of the pump motor;

[0028] The controlled end of the second switch unit is used to connect to the signal output end of the motor driver chip, the other end of the second switch unit is respectively connected to the signal output end of the motor driver chip and one end of the third switch unit, the controlled end of the third switch unit is used to connect to the signal output end of the motor driver chip, and the other end of the third switch unit is grounded;

[0029] The positive pole of the power input end of the pump motor is connected to the external voltage acquisition device through the first voltage sampling unit, and the negative pole of the power input end of the pump motor is grounded through the first current sampling unit. The first current sampling unit is used to connect to the external current acquisition device.

[0030] Specifically, the first switch unit includes a MOS tube Q1, a resistor R3 and a resistor R4. The drain of the MOS tube Q1 is connected to the power supply, the gate of the MOS tube Q1 is connected to one end of the resistor R3, and the other end of the resistor R3 is used to connect to the signal output end of the motor driver chip. The source of the MOS tube Q1 is respectively connected to one end of the resistor R4, one end of the second switch unit and the positive electrode of the power input end of the pump motor. The other end of the resistor R4 is used to connect to the signal output end of the motor driver chip.

[0031] The second switch unit includes a MOS transistor Q2, a resistor R5, and a resistor R6. The drain of the MOS transistor Q2 is connected to the source of the MOS transistor Q1, the gate of the MOS transistor Q2 is connected to one end of the resistor R5, and the other end of the resistor R5 is used to connect to the signal output terminal of the motor driver chip. The source of the MOS transistor Q2 is respectively connected to one end of the resistor R6 and one end of the third switch unit, and the other end of the resistor R6 is used to connect to the signal output terminal of the motor driver chip. The third switch unit includes a MOS transistor Q3 and a resistor R7. The source of the MOS transistor Q3 is connected to the source of the MOS transistor Q2, the gate of the MOS transistor Q3 is connected to one end of the resistor R7, and the other end of the resistor R7 is used to connect to the signal output terminal of the motor driver chip. The drain of the MOS transistor Q3 is grounded.

[0032] The first voltage sampling unit includes a resistor R8 and a resistor R9, one end of the resistor R8 is connected to the positive pole of the power input end of the pump motor, the other end of the resistor R8 is connected to one end of the resistor R9, the other end of the resistor R9 is grounded, and one end of the resistor R9 is used to connect to the external voltage acquisition device.

[0033] The first current sampling unit includes a resistor R2, one end of the resistor R2 is connected to the negative electrode of the power input end of the pump motor, the other end of the resistor R2 is grounded, and one end and the other end of the resistor R2 are both used to connect to the external current collection device.

[0034] The second current sampling unit includes a resistor R1, one end of which is connected to the source of the MOS transistor Q1, and the other end of which is connected to the drain of the MOS transistor Q2. Both ends of the resistor R1 are connected to the external current collection device. The second current sampling unit facilitates the collection of the current of the first switch unit.

[0035] The second voltage sampling unit includes a resistor R10 and a resistor R11. One end of the resistor R10 is connected to the source of the MOS transistor Q3, the other end of the resistor R10 is connected to one end of the resistor R11, the other end of the resistor R11 is grounded, and one end of the resistor R11 is connected to the external voltage acquisition device. The provision of the second voltage sampling unit facilitates acquisition of the voltage at one end of the third switch unit. The second voltage sampling unit is used to monitor the switching state of the MOS transistor Q3, and the first voltage sampling unit is used to monitor the switching state of the MOS transistor Q2.

[0036] The filter unit includes a capacitor C1, the positive electrode of which is connected to the drain of the MOS transistor Q1, and the negative electrode of which is connected to the source of the MOS transistor Q2. By providing the filter unit, capacitor C1 can be used to store energy and perform voltage stabilization and filtering in the drive circuit of the pump motor B1, thereby reducing the negative impact of the operation of the pump motor B1 on the circuit.

[0037] In the utility model, the motor driver chip is an external driving device or system, and the motor driver chip sends a driving signal H-Driver-G, a driving signal H-Driver-S, a driving signal L-Driver-G, a driving signal L-Driver-S and a driving signal Safe-Driver-G to the circuit respectively; the driving signal H-Driver-G and the driving signal H-Driver-S are driving signals of the MOS transistor Q1; the driving signal L-Driver-G and the driving signal L-Driver-S are driving signals of the MOS transistor Q2; the driving signal Safe-Driver-G is the driving signal of the MOS transistor Q3; the driving of the MOS transistor is achieved by controlling the voltage difference between the gate and the source of the MOS transistor. The dedicated motor driver chip can realize the switching of the MOS transistor Q1 by controlling the voltage difference between the driving signal H-Driver-G and the driving signal H-Driver-S, and control the driving signal L-Driver-G and the driving signal L-Driver-S. The voltage difference between iver-S can realize the switching of Q2, and the voltage difference between the control driving signal Safe-Driver-G and GND can realize the control of MOS tube Q3.

[0038] MOS transistor Q3 is added to prevent damage to the circuit due to reverse power connection. When reversed, MOS transistor Q3 does not turn on, preventing capacitor C1 from burning out. When properly connected, MOS transistor Q3 is normally open. If MOS transistor Q3 is not present in the circuit, a reverse power connection would be equivalent to capacitor C1 connecting its positive terminal to GND and its negative terminal to the power supply. Reverse charging could cause an explosion. When MOS transistor Q3 is correctly connected to the circuit and the power supply is reversed, MOS transistor Q3, acting as a switch, cannot turn on, disconnecting C1's reverse charging circuit and preventing an explosion. When the power supply is reversed, MOS transistor Q3 is also controlled by a dedicated driver chip. This driver chip fails to operate, resulting in no drive voltage at the gate of MOS transistor Q3 and thus preventing it from turning on.

[0039] Sampling resistor R1 is used to detect the current flowing through the high-side switch Q1, and sampling resistor R2 is used to detect the current flowing through the motor B1. While monitoring the current state of the power circuit, the motor speed can be estimated through the collected current to achieve sensorless and low-cost motor speed feedback control. Resistors R3, R4, R5, R6, and R7 are added to adjust the switching effect of MOS transistors Q1, Q2, and Q3 to reduce the impact of electromagnetic compatibility (EMC). The above-mentioned motor driver chip, external current collection device, and external voltage collection device can be integrated into an automotive electronic control unit (ECU).

[0040] Resistors R8 and R9 form voltage sampling 1, which collects the motor high-side voltage and monitors the status of MOS tube Q1. At the same time, the motor's back electromotive force can be obtained, and the motor speed can be estimated through the back electromotive force to achieve sensorless and low-cost motor speed feedback control. The speed is compared and verified with the current-estimated speed, further improving the circuit functional safety level. Resistors R10 and R11 form voltage sampling 2, which collects the source voltage of MOS tube Q3 and monitors the status of MOS tube Q3. Combined with voltage sampling 1, the status of MOS tube Q2 can be monitored.

[0041] The on / off switching of MOS transistors Q1 and Q2 is typically controlled by a dedicated driver chip. When MOS transistor Q1 is on and MOS transistor Q2 is off, current flows from "POWER" through MOS transistors Q1, R1, B1, R2, and GND. When current flows through pump motor B1, the motor can be driven by electrical energy. When MOS transistor Q1 is off and MOS transistor Q2 is on, the electrical energy provided by "POWER" cannot pass through MOS transistor Q1, and thus cannot power pump motor B1. At this time, pump motor B1 continues to rotate by relying on inertia from the previous moment. At the same time, due to the internal parasitic inductance of the motor, the internal current is freewheeling. This current flows from pump motor B1 through resistor R2, GND, MOS transistor Q3, MOS transistor Q2, and back to pump motor B1, thus circulating the electrical energy internally. MOS transistors Q1 and Q2 are typically controlled using alternating PWM control.

[0042] The external current acquisition device and the external voltage acquisition device can be a control device that integrates the automobile hollow system with voltage and current acquisition functions, namely the automobile ECU or MCU. The ECU or MCU calculates the speed of the pump motor B1 through current or voltage.

[0043] The embodiment of the present utility model sets three switch units in series, and uses the first switch unit and the second switch unit to collaboratively control the start and stop of the pump motor B1, and uses the third switch unit to prevent circuit damage caused by reverse power connection; when the first switch unit is turned on, the second switch unit is turned off and the third switch unit is turned on, the pump motor B1 is powered on and started; when the first switch unit is turned off, the second switch unit is turned on and the third switch unit is turned on, the pump motor B1 is powered off; when the power supply is reversed, one end of the first switch unit is grounded or connected to the negative pole of the power supply, and the other end of the third switch unit is connected to the positive pole of the power supply. The voltage at the other end of the third switch unit is greater than the voltage at the controlled end. The third switch unit is disconnected, and the entire circuit is powered off, thereby preventing circuit damage caused by reverse power connection. At the same time, by setting up a first voltage sampling unit and a first current sampling unit, the external voltage acquisition device can collect the voltage of the positive pole of the power input terminal of the pump motor B1 through the first voltage sampling unit, and the external current acquisition device can collect the working current of the pump motor B1 through the first current sampling unit, thereby facilitating the external control system or device to characterize or calculate the speed of the pump motor B1 according to the voltage of the positive pole of the power input terminal of the pump motor B1 and the working current. Compared with the prior art of setting a speed sensor to monitor the speed of the pump motor B1, the cost of the utility model is lower.

[0044] In other embodiments, an automotive electric motor drive device is provided, including the pump motor drive circuit of the redundant brake unit. In this embodiment, the automotive electric motor drive device can be a power motor drive device or an auxiliary motor drive device for the vehicle. The automotive electric motor drive device can also be used for the vehicle's auxiliary motor; the auxiliary motor can be a pump motor, a seat adjustment motor, a door control motor, a sunroof control motor, a trunk control motor, etc.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the concept and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A pump motor drive circuit for a redundant brake unit, characterized in that: It includes a first switch unit, a second switch unit, a third switch unit, a first voltage sampling unit and a first current sampling unit; One end of the first switch unit is connected to a power supply, a controlled end of the first switch unit is used to connect to a signal output end of a motor driver chip, and the other end of the first switch unit is respectively connected to the signal output end of the motor driver chip, one end of the second switch unit, and a positive electrode of a power input end of the pump motor; The controlled end of the second switch unit is used to connect to the signal output end of the motor driver chip, the other end of the second switch unit is respectively connected to the signal output end of the motor driver chip and one end of the third switch unit, the controlled end of the third switch unit is used to connect to the signal output end of the motor driver chip, and the other end of the third switch unit is grounded; The positive pole of the power input end of the pump motor is connected to the external voltage acquisition device through the first voltage sampling unit, and the negative pole of the power input end of the pump motor is grounded through the first current sampling unit. The first current sampling unit is used to connect to the external current acquisition device.

2. The pump motor drive circuit of the redundant brake unit according to claim 1, characterized in that: The first switch unit includes a MOS tube Q1, a resistor R3 and a resistor R4. The drain of the MOS tube Q1 is connected to the power supply, the gate of the MOS tube Q1 is connected to one end of the resistor R3, and the other end of the resistor R3 is used to connect to the signal output end of the motor driver chip. The source of the MOS tube Q1 is respectively connected to one end of the resistor R4, one end of the second switch unit and the positive electrode of the power input end of the pump motor. The other end of the resistor R4 is used to connect to the signal output end of the motor driver chip.

3. The pump motor drive circuit of the redundant brake unit according to claim 2, characterized in that: The second switch unit includes a MOS transistor Q2, a resistor R5, and a resistor R6. The drain of the MOS transistor Q2 is connected to the source of the MOS transistor Q1, the gate of the MOS transistor Q2 is connected to one end of the resistor R5, and the other end of the resistor R5 is used to connect to the signal output end of the motor driver chip. The source of the MOS transistor Q2 is respectively connected to one end of the resistor R6 and one end of the third switch unit. The other end of the resistor R6 is used to connect to the signal output end of the motor driver chip.

4. The pump motor drive circuit of the redundant brake unit according to claim 3, characterized in that: The third switch unit includes a MOS transistor Q3 and a resistor R7. The source of the MOS transistor Q3 is connected to the source of the MOS transistor Q2, the gate of the MOS transistor Q3 is connected to one end of the resistor R7, the other end of the resistor R7 is used to connect to the signal output end of the motor drive chip, and the drain of the MOS transistor Q3 is grounded.

5. The pump motor driving circuit of the redundant brake unit according to claim 4, characterized in that: The first voltage sampling unit includes a resistor R8 and a resistor R9, one end of the resistor R8 is connected to the positive pole of the power input end of the pump motor, the other end of the resistor R8 is connected to one end of the resistor R9, the other end of the resistor R9 is grounded, and one end of the resistor R9 is used to connect to the external voltage acquisition device.

6. The pump motor driving circuit of the redundant brake unit according to claim 4, characterized in that: The first current sampling unit includes a resistor R2, one end of the resistor R2 is connected to the negative electrode of the power input end of the pump motor, the other end of the resistor R2 is grounded, and one end and the other end of the resistor R2 are both used to connect to the external current collection device.

7. The pump motor driving circuit of the redundant brake unit according to claim 4, characterized in that: A second current sampling unit is also included, which includes a resistor R1, one end of the resistor R1 is connected to the source of the MOS transistor Q1, and the other end of the resistor R1 is connected to the drain of the MOS transistor Q2, and one end and the other end of the resistor R1 are both used to connect to the external current collection device.

8. The pump motor driving circuit of the redundant brake unit according to claim 4, characterized in that: It also includes a second voltage sampling unit, which includes a resistor R10 and a resistor R11. One end of the resistor R10 is connected to the source of the MOS tube Q3, the other end of the resistor R10 is connected to one end of the resistor R11, the other end of the resistor R11 is grounded, and one end of the resistor R11 is used to connect to the external voltage collection device.

9. The pump motor driving circuit of the redundant brake unit according to claim 4, characterized in that: The device further includes a filter unit, which includes a capacitor C1 , wherein the positive electrode of the capacitor C1 is connected to the drain of the MOS transistor Q1 , and the negative electrode of the capacitor C1 is connected to the source of the MOS transistor Q2 .

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