KR102640429B1 - Circuit for protecting Electronic controller unit, Electronic controller unit, and System for assisting Steering - Google Patents

Abstract

This disclosure relates to ECU protection circuits, electronic control units, and steering assistance systems. Specifically, the ECU protection circuit according to the present disclosure includes a Zener diode that allows a reverse current to flow when the phase-to-phase voltage of the steering motor is higher than a preset breakdown voltage, and a second diode that turns on when the reverse current is applied and allows the first current to flow. It includes one switch and a second switch that turns on when the first current flows and allows the second current to flow to conduct the supply voltage of the battery to the PCO switch, where the PCO switch is turned on when the supply voltage is applied.

Description

ECU protection circuit, electronic control unit, and steering assistance system {Circuit for protecting Electronic controller unit, Electronic controller unit, and System for assisting Steering}

This disclosure relates to ECU protection circuits, electronic control units, and steering assistance systems.

A vehicle's steering assistance system is a system that assists the driver in changing the vehicle's direction of travel at the driver's will, and assists the driver in driving the vehicle more easily by generating a steering assistance force in the desired driving direction.

This steering assistance system is implemented with a hydraulic power assist steering device (HPS: Hydraulic Power Steering Apparatus) and an electronic power assist steering device (EPS: Electric Power Steering Apparatus).

Recently, a redundant system that adds the same configuration as the specific configuration is applied to the steering assistance system in case a specific configuration included in the system fails, and fail safety is implemented based on this redundant system. I'm doing it.

However, when fail safety is implemented based on a redundant system, back electromotive force may occur in the steering motor included in the steering assistance system, and in this case, the electronic control unit that controls the steering motor by the back electromotive force. There is a problem that the (electronic controller unit) may be damaged.

Therefore, when back electromotive voltage is generated in a steering motor, there is a need for technology to effectively prevent it.

Against this background, the present disclosure seeks to provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can prevent back electromotive voltage of a steering motor while implementing fail safety based on a redundant system.

In addition, the present disclosure seeks to provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can protect the ECU by effectively preventing back electromotive voltage of the steering motor using a simple circuit.

In addition, the present disclosure seeks to provide an ECU protection circuit, an electronic control unit, and a steering assistance system that provide driving stability by more reliably implementing fail safety.

In order to solve the above-described problem, in one aspect, the present disclosure is a PCO (Phase Cut Off) switch protection circuit, one end of which is connected to a steering motor, and the phase voltage of the steering motor is a preset breakdown voltage (Break down voltage). In the above case, a Zener diode that allows a reverse current to flow, a first end connected to the other end of the Zener diode, a first switch that turns on when a reverse current is applied and allows the first current to flow, and one end connected to the other end of the first switch. It includes a second switch that is connected and turns on when the first current flows, so that the second current flows and the supply voltage of the battery is conducted to the PCO switch, where the reverse current flows from the steering motor to the Zener diode, and the first current flows. , flows from one end of the second switch to the other end of the first switch, and the PCO switch provides an ECU protection circuit that is turned on when the supply voltage is applied.

In another aspect, the present disclosure includes a supply voltage switch that conducts the supply voltage of the battery, an inverter that outputs a control signal to control the operation of the steering motor, and a supply voltage switch that conducts the control signal to the steering motor or supplies the control signal. When back electromotive voltage occurs in the PCO (Phase Cut Off) switch, the supply voltage switch, the MCU (Micro Controller Unit) that controls each of the inverter and the PCO switch, and the steering motor, the battery's supply voltage is conducted to the PCO switch. An electronic control unit is provided that includes an ECU protection unit that causes the PCO switch to turn on.

In another aspect, the present disclosure provides a first electronic control unit including a first MCU, a first inverter, and a first PCO switch, and a second electronic control unit including a second MCU, a second inverter, and a second PCO switch. and a battery supplying power to the first electronic control unit and the second electronic control unit, a single winding steering motor controlled by the first electronic control unit or the second electronic control unit, and a first electronic control unit. When the control right to control the steering motor is transferred between the unit and the second electronic control unit, if the phase-to-phase voltage of the steering motor is higher than the preset reference voltage, the PCO switch included in the electronic control unit to which the control right is transferred changes the battery supply voltage. Provides a steering assistance system that includes an ECU protection circuit that applies to

As described above, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can prevent back electromotive voltage of a steering motor while implementing fail safety based on a redundant system.

In addition, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can protect the ECU by effectively preventing back electromotive voltage of the steering motor using a simple circuit.

In addition, according to the present disclosure, by using a simpler circuit, it is possible to provide an ECU protection circuit, an electronic control unit, and a steering assistance system that minimizes the space occupied by the device, contributes to high integration, and minimizes the manufacturing cost. there is.

In addition, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that provide driving stability by more stably implementing fail safety.

In addition, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can efficiently use the battery by applying a circuit optimized for the dark current of the battery.

1 is a block diagram for explaining a steering assistance system according to the present disclosure.
Figure 2 is a diagram for explaining a phenomenon that occurs when the ECU fails in the steering assistance system according to the present disclosure.
Figure 3 is a block diagram schematically showing a first embodiment of a steering assistance system according to the present disclosure.
Figure 4 is a block diagram schematically showing a second embodiment of the steering assistance system according to the present disclosure.
Figure 5 is a block diagram schematically showing a third embodiment of a steering assistance system according to the present disclosure.
Figure 6 is a block diagram schematically showing an ECU protection circuit according to the present disclosure.
Figure 7 is a circuit diagram showing the connection relationship between the ECU, the ECU protection circuit, and the steering motor according to the present disclosure.
FIG. 8 is a circuit diagram specifically showing the first embodiment of the ECU protection circuit of FIG. 7.
FIG. 9 is a circuit diagram specifically showing the second embodiment of the ECU protection circuit of FIG. 7.
Figure 10 is a diagram showing the waveform of the supply voltage applied to the PCO switch.
FIG. 11 is a circuit diagram specifically showing the third embodiment of the ECU protection circuit of FIG. 7.
FIG. 12 is a diagram showing an embodiment of each of the first switch and the second switch included in the ECU protection circuit of FIG. 7.
Figure 13 is a block diagram schematically showing another embodiment of an ECU according to the present disclosure.

Hereinafter, some embodiments of the present disclosure will be described in detail through illustrative drawings. In describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, or order of the component is not limited by the term. When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there is another component between each component. It will be understood that elements may be “connected,” “combined,” or “connected.”

Figure 1 is a block diagram for explaining the steering assistance system 100 according to the present disclosure.

Referring to FIG. 1, the steering assistance system 100 according to the present disclosure refers to a system that assists steering of a vehicle.

This steering assistance system 100 includes a battery 110, a first electronic control unit (ECU) 120, a second electronic control unit 130, a steering motor 140, and a sensor 150. It can be included.

The battery 110 may supply power to the first ECU 120 and the second ECU 130. Here, the supply power may be supply voltage or supply current. In other words, supplying power may mean supplying voltage or current. In addition, since voltage and current are closely related through Ohm's law, hereinafter, the fact that voltage is conducted and applied to and transmitted to a specific configuration, element, etc. has the same meaning as the current flowing and applied and transmitted to a specific configuration, element, etc. You can.

For example, the battery 110 is configured as an integrated unit and can supply power to both the first ECU 120 and the second ECU 130, and supplies power to only one electronic control unit in a specific state, When the state changes, it can supply power to other electronic control units.

As another example, the battery 110 may be composed of two or more battery modules (not shown), and each battery module may be connected to each of the first ECU 120 and the second ECU 130 to supply power. However, it is not limited to this.

Meanwhile, the steering assistance system 100 according to the present disclosure may implement a redundant system by including two or more ECUs that output electrical signals to the steering motor 140. For example, the steering assistance system 100 according to the present disclosure implements a redundant system including the first ECU 120 and the second ECU 130.

Here, the first ECU 120 and the second ECU 130 receive steering information from the sensor 150, calculate a control signal for controlling the steering motor 140 based on the steering information, and use the calculated control signal. Can be output to the steering motor 140.

For a specific example, when the driver holds and operates the steering wheel, the sensor 150 detects the rotation angle (steering angle) generated by the steering wheel, inputs the corresponding steering angle information to the ECUs 120 and 130, and the ECU (120, 130) outputs a control signal based on the input steering angle information.

These ECUs 120 and 130 may include a plurality of components that perform respective functions, such as converting the input supply voltage of the battery 110 and blocking or resuming the supply of control signals. For example, the first ECU 120 includes a first supply voltage switch 121, a first micro controller unit (MCU) 122, an inverter (123), and a first PCO (Phase Cut Off). It includes a switch 124, etc., and the second ECU 130 also includes a second supply voltage switch 131, a second MCU 132, a second inverter 133, and a second supply voltage switch 131 in the same manner as the first ECU 120. It may include a PCO switch 134, etc.

The supply voltage switches 121 and 131 may turn on the supply voltage of the battery 110. Specifically, when the supply voltage switches 121 and 131 are turned off, the supply voltage of the battery 110 is blocked, and when the supply voltage switches 121 and 131 are turned on, the supply voltage of the battery 110 is turned on to the ECU (120). , 130) can be conducted.

The inverters 123 and 133 may convert the supply voltage of the battery 110 from direct current (DC) to alternating current (AC) and apply the AC voltage to the steering motor 140. Specifically, the inverters 123 and 133 may convert the supply voltage of the battery 110 into alternating current and apply the alternating current voltage to each phase of the steering motor 140.

The PCO switches 124 and 134 can allow the AC voltage output from the inverters 123 and 133 to conduct or block the steering motor 140. Specifically, when the PCO switches 124 and 134 are turned off, the AC voltage is blocked, and when the PCO switches 124 and 134 are turned on, the AC voltage can be applied to each phase of the steering motor 140.

The MCU (122, 132) can control turn-on/turn-off of each of the supply voltage switches (121, 131), inverters (123, 133), and PCO switches (124, 134).

Here, either the first ECU 120 or the second ECU 130 may operate as the main ECU. For example, when the first ECU 120 operates as the main ECU, the first ECU 120 calculates a control signal and outputs it to the steering motor 140, and while the first ECU 120 operates, the control signal is calculated and output to the steering motor 140. 2 ECU 130 does not operate. However, it is not limited to this, and the second ECU 130 may operate as the main ECU.

Meanwhile, both the first ECU 120 and the second ECU 130 can operate as main ECUs. At this time, the two ECUs (120, 130) calculate and output the target control signal by dividing it, and the plurality of control signals output by each of the two ECUs (120, 130) are integrated and finally applied to the steering motor 140. there is.

The steering motor 140 can be driven by receiving a control signal from the ECU (120 or 130). Specifically, when a command current corresponding to a control signal is input from the ECU (120 or 130), the steering motor 140 can be driven at a rotation speed and torque corresponding to the command current.

The sensor 150 can detect steering information such as the steering angle and torque of the steering wheel, and output a corresponding detection signal to the ECU (120, 130). This sensor 150 may mean, for example, a steering angle sensor that detects the steering angle of the steering wheel, a torque sensor that detects torque, etc.

In this specification, for convenience of explanation, the embodiment is described using two ECUs, but it is not limited thereto, and the same can be applied to the case of three or more ECUs.

Meanwhile, the steering assistance system 100 according to the present disclosure can perform fail safe based on a redundant system. For example, the first ECU 120 and the second ECU 130 are connected via a bus to perform internal communication, and information about the status of each ECU 120 and 130 is transmitted through internal communication, thereby The steering assistance system 100 according to the disclosure performs fail safety based on a redundant system.

This internal communication is, for example, CAN communication that can transmit and receive messages between the first ECU 120 and the second ECU 130 through the first CAN bus (not shown) and the second CAN bus (not shown). It may be possible, but it is not limited to this.

Below, we will explain how to perform fail safety based on a redundant system and the phenomena that may occur at this time.

FIG. 2 is a diagram for explaining a phenomenon that occurs when the ECU fails in the steering assistance system 100 according to the present disclosure.

Referring to FIG. 2, in the steering assistance system 100 according to the present disclosure, there is a main ECU and a sub ECU among two or more ECUs, and the main ECU controls the steering motor 140, but does not control the status or condition of the vehicle. , if the main ECU, etc., malfunctions, the main ECU transfers control of the steering motor 140 to the sub ECU, so that the steering assistance system 100 can perform fail safety.

For example, when the first ECU 120 is the main ECU and the second ECU 130 is the sub ECU, the first ECU 120 generates a target control signal necessary for steering the vehicle and operates the steering motor 140. outputs to , and the second ECU 130 waits. If the first ECU 120 fails, the first ECU 120 transfers control to the second ECU 130, and the second ECU 130 to which control is transferred generates a target control signal and steers. Output to motor 140.

At this time, the steering motor 140 is generally driven at a high RPM (Revolutions Per Minute), so when the first ECU 120, which operates as the main ECU, fails, the steering motor 140 generates a back electromotive force (Back ElectroMotive Force). ; BEMF) occurs instantaneously. When a back electromotive voltage is generated, the back electromotive voltage is applied to the second ECU 130, and the second PCO switch 134 included in the second ECU 130 may be damaged.

Therefore, it is necessary to prevent damage to the ECU while implementing fail safety based on a redundancy system.

Hereinafter, the steering assistance system 100 including a circuit to prevent damage to the ECU due to the back electromotive voltage of the steering motor 140 will be described.

FIG. 3 is a block diagram schematically showing a first embodiment of the steering assistance system 100 according to the present disclosure, and FIG. 4 is a block diagram schematically showing a second embodiment of the steering assistance system 100 according to the present disclosure. 5 is a block diagram schematically showing a third embodiment of the steering assistance system 100 according to the present disclosure.

The steering assistance system 100 according to the present disclosure may include a first ECU 120, a second ECU 130, a battery 110, a steering motor 140, and an ECU protection module 160.

The first ECU 120 and the second ECU 130 are the same as those described above with reference to FIGS. 1 and 2 and are therefore omitted.

The battery 110 may supply power to the first ECU 120, the second ECU 130, and the ECU protection module 160.

The steering motor 140 may be controlled by the first ECU 120 or the second ECU 130. Specifically, it can be controlled by one ECU operating as the main ECU among the first ECU 120 and the second ECU 130. For example, when the first ECU 120 operates as the main ECU, the steering motor 140 is preferentially controlled by the first ECU 120, and when the second ECU 130 operates as the main ECU. , the steering motor 140 is preferentially controlled by the second ECU (130).

Since the steering motor 140 is controlled by one ECU operating as the main ECU among the first ECU 120 and the second ECU 130, it may preferably be a single winding motor.

When the control right for controlling the steering motor 140 is transferred between the first ECU 120 and the second ECU 130, the ECU protection module 160 ensures that the phase-to-phase voltage of the steering motor 140 is higher than the preset reference voltage. If so, the supply voltage of the battery 110 can be applied to the PCO switch 124 or 134 included in the ECU 120 or 130 to which control rights have been transferred.

For a specific example, when the first ECU 120 operates as the main ECU, if the first ECU 120 fails, control of the first ECU 120 is transferred to the second ECU 130, and at this time, steering When a back electromotive voltage is generated in the motor 140 and the phase-to-phase voltage of the steering motor 140 becomes higher than the reference voltage, the ECU protection module 160 applies the supply voltage of the battery 110 to the second PCO switch 134. .

When a back electromotive voltage occurs in the steering motor 140, the supply voltage of the battery 110 is applied to the PCO switches 124 and 134 by the ECU protection module 160, and the battery 110 and the ECU 120 and 130 And when the steering motor 140 is electrically connected, the back electromotive voltage of the steering motor 140 is absorbed into the battery 110 and gradually decreases.

Meanwhile, there may be more than one ECU protection module 160, and one ECU protection module 160 may be connected to an ECU operating as a sub-ECU.

For example, with reference to FIG. 3, when the first ECU 120 is the main ECU and the second ECU 130 is the sub ECU, the ECU protection module 160 is connected to the battery 110 and the second ECU 130. and electrically connected to the steering motor 140.

For another example with reference to FIG. 4, when the first ECU 120 is a sub-ECU and the second ECU 130 is the main ECU, the ECU protection module 160 protects the battery 110 and the first ECU 120. ) and is electrically connected to the steering motor 140.

For another example with reference to FIG. 5, the first ECU protection module 161 is electrically connected to the battery 110, the first ECU 120, and the steering motor 140, and the second ECU protection module 162 ) is electrically connected to the battery 110, the second ECU 130, and the steering motor 140. At this time, the first ECU protection module 161 is operable when the second ECU 130 fails, and the second ECU protection module 162 is operable when the first ECU 120 fails.

If the steering motor 140 is a three-phase motor, the phase voltage of the steering motor 140 may be a u-phase, v-phase, or w-phase voltage. However, it is not limited to this.

The reference voltage is a reference value for determining whether a counter electromotive voltage has occurred in the steering motor 140, and can be designed in advance to correspond to the internal voltage of the PCO switches 124 and 134. Preferably, the reference voltage may be the breakdown voltage of the Zener diode included in the ECU protection circuit 200, which will be described later with reference to FIGS. 6 and 8 to 10. However, it is not limited to this.

Although not shown, the steering assistance system 100 according to the present disclosure shown in FIGS. 3 to 5 may include the sensor 150 shown in FIG. 1.

Hereinafter, the ECU protection circuit 200 according to the present disclosure will be described in detail.

Figure 6 is a block diagram schematically showing the ECU protection circuit 200 according to the present disclosure.

Referring to FIG. 6, the ECU protection circuit 200 according to the present disclosure may include a Zener diode 210, a first switch 220, and a second switch 230.

Zener diode (210) is a type of diode and can pass current in the forward direction like a general diode. However, unlike general diodes, when a voltage higher than the breakdown voltage is applied in the reverse direction, current flows in the reverse direction.

For example, when one end of the Zener diode 210 is connected to the steering motor 140, and the phase-to-phase voltage of the steering motor 140 is higher than the preset breakdown voltage, reverse current flows in the reverse direction. That is, the reverse current flows from the steering motor 140 to the Zener diode 210.

The first switch 220 may be turned on when a reverse current is applied from the Zener diode 210. For example, one end of the first switch 220 is connected to the other end of the Zener diode 200, and when a reverse current is applied to one end of the first switch 220, it is turned on. The first current generated by flows through the first switch 220.

The second switch 230 may be turned on when the first current generated by the first switch 220 flows. For example, one end of the second switch 230 is connected to the other end of the first switch 220, and when the first current flows and a voltage is applied to one end of the first switch 220, it is turned on.

When the second switch 230 is turned on, the second current generated by the turn-on of the second switch 230 flows through the second switch 230. Also, by turning on the second switch 230, the supply voltage of the battery 110 may be conducted to the PCO switch 320 included in the ECU 300.

The PCO switch 320 may be turned on when the supply voltage is applied. When the PCO switch 320 is turned on by the supply voltage, the counter electromotive voltage may be absorbed into the battery 110.

Meanwhile, the PCO switch 320 may be turned on by a control signal from the MCU 310 included in the ECU 300. The operation of turning on the PCO switch 320 by the supply voltage of the battery 110 or the control signal of the MCU 310 will be described later with reference to FIG. 11.

As described above, the ECU protection circuit 200 according to the present disclosure provides the effect of protecting the PCO switch 320 by reducing the back electromotive voltage generated in the steering motor 140.

Hereinafter, the connection relationship between the ECU protection circuit 200, the ECUs 120, 130, and 300, and the steering motor 140 will be described in detail using a circuit diagram. For convenience, the first ECU 120 as shown in FIG. 3 The explanation will be based on the steering assistance system 100 and the three-phase steering motor 140 operating as the main ECU.

FIG. 7 is a circuit diagram showing the connection relationship between the ECUs 120 and 130, the ECU protection circuit 200, and the steering motor 140 according to the present disclosure.

Referring to FIG. 7, supply voltage switches 121 and 131, inverters 123 and 133, and PCO switches 124 and 134 included in each of the first ECU 120 and the second ECU 130 according to the present disclosure. can all be implemented with FETs. Additionally, when the steering motor 140 is a three-phase motor, the inverters 123 and 133 are implemented with 6 FETs to correspond to each phase of the steering motor 140, and the PCO switches 124 and 134 are implemented with 3 FETs. It can be implemented as:

The first MCU (not shown) included in the first ECU 120 may be connected to the gate of the first supply voltage switch 121, the gate of the first inverter 123, and the gate of the first PCO switch 124. .

When the first supply voltage switch 121 is turned on, the supply voltage (v _bat ) of the battery 110 is conducted to the first inverter 123, and the first inverter 123 is connected to the supplied voltage of the battery 110. (v _bat ) is switched to apply an alternating current voltage to each of the u-phase (141), v-phase (142), and w-phase (143) of the steering motor 140 according to the timing control of the first MCU.

Meanwhile, the second MCU (not shown) of the second ECU 130 according to the present disclosure also has the gate of the second supply voltage switch 131, the gate of the second inverter 133, and the gate of the second PCO switch 134. can be connected to

At this time, the second supply voltage switch 131 is turned on even when the second ECU 130 is in a standby state so that the counter electromotive voltage of the steering motor 140 is absorbed into the battery 110 connected to the second ECU 130. You can. On the other hand, when the second ECU 130 is in a standby state, the second PCO switch 134 remains turned off.

The ECU protection circuit 200 is connected to each of the u-phase 141, v-phase 142, and w-phase 143 of the steering motor 140, and may be connected to each of the gates of the second PCO switch 134.

When the first ECU 120 fails and a back electromotive voltage is generated in the steering motor 140, the ECU protection circuit 200 applies the supply voltage of the battery 110 to the gate of the second PCO switch 134 to 2 The second PCO switch 134 can be protected by turning on the PCO switch 134 and absorbing the back electromotive voltage into the battery 110 connected to the second ECU 130.

Below, the operation of the ECU protection circuit 200 will be described in detail using a specific circuit diagram of the ECU protection circuit 200.

FIG. 8 is a circuit diagram specifically showing the first embodiment of the ECU protection circuit 200 of FIG. 7.

Referring to FIG. 8, there are a plurality of Zener diodes included in the ECU protection circuit 200, and the plurality of Zener diodes 210 may be connected to each phase of the steering motor 140.

For a specific example, the steering motor 140 is a three-phase motor, and each of the U-phase 141, V-phase 142, and W-phase 143 of the steering motor 140 includes a plurality of Zener diodes 210. It is connected to each end. Also, the other ends of each of the plurality of Zener diodes 210 are connected to the first switch 220a.

Meanwhile, the first switch 220a and the second switch 230a may be implemented as a junction transistor (Bipolar Junction Transistor, BJT). Preferably, the first switch 220a may be an NPN transistor, and the second switch 230a may be a PNP transistor. However, it is not limited to this.

For a specific example, when the first switch 220a is an NPN transistor including three terminals, the first terminal of the first switch 220a is connected to the other terminal of the Zeno diode, and the first switch 220a The second terminal of is connected to the second switch 230a, and the third terminal of the first switch 220a is grounded.

And, if the second switch 230a is a PNP transistor including three terminals like the first switch 220a, the first terminal of the second switch 230a is connected to the first switch 220a. The second terminal of the second switch 230a is connected to the PCO switch 320, and the third terminal of the second switch 230a is connected to the battery 110.

Here, preferably, the first terminal may be a base, the second terminal may be a collector, and the third terminal may be an emitter. However, it is not limited to this.

When the phase-to-phase voltage of the steering motor 140 is higher than the breakdown voltage of the Zener diode 210, the reverse current ① flows from the steering motor 140 to the Zener diode 210, and the reverse current ① flows into the first switch. When applied to the first terminal of 220a, the voltage is applied to the first terminal of the first switch 220a, and the first switch 220a is turned on.

When the first switch 220a is turned on, the first current ② flows from the first terminal of the second switch 230a to the second terminal of the first switch 220a, and when the first current flows, the second switch ② A voltage is applied to the first terminal of 230a), and the second switch 230a is turned on.

When the second switch 230a is turned on, the second current ③ flows from the battery 110 to the driver ICs 321, 322, and 323 of the PCO switch 320, and the supply voltage of the battery 110 When (v _bat ) is applied to the driver IC (321, 322, 323) of the PCO switch 320 via the second switch (230a), the driver IC (321, 322 and 323) output a turn-on signal to the PCO switch 320. Then, the PCO switch 320 that receives the turn-on signal is turned on.

Meanwhile, since the back electromotive voltage fluctuates irregularly, it may be difficult for the supply voltage of the battery 110 to be stably applied to the driver ICs 321, 322, and 323 of the PCO switch 320.

Hereinafter, the ECU protection circuit 200, in which the supply voltage of the battery 110 is more stably applied to the PCO switch 320 by modifying the waveform of the supply voltage, will be described.

FIG. 9 is a circuit diagram specifically showing the second embodiment of the ECU protection circuit 200 of FIG. 7, and FIG. 10 is a diagram showing the waveform of the supply voltage applied to the PCO switch 320.

Referring to FIG. 9, as described above with reference to FIG. 8, when a back electromotive voltage is generated in the steering motor 140, the first switch and the second switch 230a are turned on, and the supply voltage of the battery 110 is turned on. This is applied to the driver ICs 321, 322, and 323 of the PCO switch 320, and the PCO switch 320 is turned on.

Here, the ECU protection circuit 200 may further include a capacitor 250 that modifies the waveform of the supply voltage applied to the PCO switch 320.

At this time, the first terminal of the capacitor 250 may be connected between the second switch 230a and the PCO switch 320, and the second terminal of the capacitor 250 may be grounded.

There may be a plurality of capacitors 250, and the plurality of capacitors 250 may be connected to each driver IC 321, 322, and 323 of the PCO switch 320. For example, when the steering motor 140 is a three-phase motor, each of the three capacitors 250 is between the second switch 230a and the driver ICs 321, 322, and 323 of the PCO switch 320. can be connected to

Here, when the diode 240 is connected between the second switch 230a and the driver ICs 321, 322, and 323 of the PCO switch 320, the first terminal of the capacitor 250 is preferably a diode. It may be connected between (240) and the driver IC (321, 322, 323) of the PCO switch (320). However, it is not limited to this.

When the capacitor 250 is connected, the waveform of the supply voltage applied to the PCO switch 320 may be modified depending on the time constant of the RC circuit. This time constant can be determined by the equivalent resistance of the conductor and the capacitance or capacitance of the capacitor 250.

For example, with reference to FIG. 10 , the waveform of the supply voltage applied to the PCO switch 320 may include a rising section (A1), a maintaining section (A2), and a falling section (A3) of the supply voltage.

In this case, when the time constant is changed by adjusting the capacitance of the capacitor 250, a waveform in which the rising section (A1) and falling section (A3) increase and the maintaining section (A2) decreases occurs, or the rising section (A1) A waveform may occur in which the falling section (A3) is decreased and the sustain section (A2) is increased. In particular, when the time constant is very small, the waveform of the supply voltage applied to the PCO switch 320 may be a square wave.

While the supply voltage applied to the PCO switch 320 is applied, the PCO switch 320 may be turned on.

Meanwhile, after the falling section A3, the back electromotive voltage decreases and the first and second switches are turned off, so the supply voltage of the battery 110 is not applied to the PCO switch 320. At this time, the PCO switch 320 may be turned off during the first period (B) after the falling period (A3).

However, the control right is transferred immediately after the falling section A3, and the turn-on and turn-off of the PCO switch 320 is controlled by the MCU 310 included in the ECU 300, which can operate normally, so the first period (B ) can be a very short time or very close to O.

When the second period (C) arrives after the first period (B), the PCO switch 320 may be turned on and off controlled by the ECU 300 to which control rights have been transferred. That is, in the second period (C) when the control right is transferred, the on/off of the PCO switch 320 can be controlled by the MCU 310 that is operating normally.

As described above, the ECU protection circuit 200 according to the present disclosure provides the effect of preventing back electromotive voltage more stably even if back electromotive voltage occurs in the steering motor 140.

FIG. 11 is a circuit diagram specifically showing the third embodiment of the ECU protection circuit 200 of FIG. 7, and FIG. 12 is a circuit diagram showing the first switch 220 and the second switch (220) included in the ECU protection circuit 200 of FIG. 7. 230) This is a drawing showing each example.

Referring to FIG. 11, the first switch 220b and the second switch 230b included in the ECU protection circuit 200 according to the present disclosure are the first switch 220b and the second switch 230b shown in FIG. 8. ) and may be a different transistor.

For example, the first switch 220b and the second switch 230b are field-effect transistors (FETs), and preferably the first switch 220b is an NMOS transistor, and the second switch (230b) may be a PMOS transistor, but is not limited thereto.

For a specific example, when the first switch 220b is an NMOS transistor including three terminals, the first terminal of the first switch 220b is connected to the other terminal of the Zeno diode, and the first switch 220b The second terminal of is connected to the second switch 230b, and the third terminal of the first switch 220b is grounded.

And, when the second switch 230b is a PMOS transistor including three terminals, the first terminal of the second switch 230b is connected to the first switch 220b, and the first terminal of the second switch 230b is connected to the first switch 220b. The second terminal is connected to the PCO switch 320, and the third terminal of the second switch 230b is connected to the battery 110.

Here, preferably, the first terminal may be a gate, the second terminal may be a drain, and the third terminal may be a source. However, it is not limited to this.

Meanwhile, the first switch 220 and the second switch 230 can not only be implemented as MOSFETs that do not include a bulk terminal as shown in FIG. 11, but also as an N-channel FET as shown in FIG. 12. It may be a first switch 220c that is a P-channel FET and a second switch 230c that is a P-channel FET. However, it is not limited to this.

Meanwhile, the operating method of the ECU protection circuit 200 shown in FIG. 11 is the same as shown in FIG. 8, and the ECU protection circuit 200 shown in FIG. 11 also uses a capacitor 250 as shown in FIG. 9. More may be included.

Meanwhile, the above-described ECU protection module 160 and ECU protection circuit 200 may be implemented as an IC chip (Integrated Circuit chip) and included within the above-described ECU 300.

Hereinafter, the ECU 300, which includes a component that performs the functions of the ECU protection module 160 and the ECU protection circuit 200 according to the present disclosure, will be described.

Figure 13 is a block diagram schematically showing another embodiment of the ECU 300 according to the present disclosure.

Referring to FIG. 13, the ECU 300 according to the present disclosure receives power from the battery 110, as described above with reference to FIG. 1, and operates the steering motor based on steering information input from the sensor 150. (140) can be controlled.

Additionally, as described above, the ECU 300 may include an MCU 310, a PCO switch 320, a supply voltage switch 330, and an inverter 240. Here, the supply voltage switch 330 conducts the supply voltage of the battery 110, the inverter 240 outputs a control signal to control the operation of the steering motor 140, and the PCO switch 320 provides a control signal. By turning on or off, the MCU 310 can control each of the supply voltage switch 330, inverter 240, and PCO switch 320.

However, the ECU 300 shown in FIG. 13, unlike the first ECU 120 and the second ECU 130 described above with reference to FIGS. 1 to 10, has an ECU protection unit (PU, 350). More may be included.

Similar to the above-described ECU protection module 160 and ECU protection circuit 200, the ECU protection unit 350 determines whether a counter electromotive voltage is generated in the steering motor 140 based on the phase voltage of the steering motor 140. After making the determination, if a back electromotive voltage occurs in the steering motor 140, the ECU protection unit 350 may conduct the supply voltage of the battery 110 to the PCO switch 320 so that the PCO switch 320 is turned on.

For example, the ECU protection unit 350 compares the phase-to-phase voltage with a preset reference voltage, and if the phase-to-phase voltage is greater than the reference voltage, it determines that the counter electromotive voltage has occurred.

Here, the reference voltage may be set based on the withstand voltage of the PCO switch, as described above, and may be set equal to the breakdown voltage of the Zeno diode 210 included in the ECU protection unit 350. However, it is not limited to this.

Here, as described above with reference to FIG. 7, the supply voltage switch 330 maintains the turn-on state before the counter electromotive voltage occurs, and the PCO switch 320 maintains the turn-off state before the counter electromotive voltage occurs. When maintained and a back electromotive voltage is generated, the ECU protection unit 350 may switch to the turn-on state.

Here, as described above with reference to FIG. 10, the PCO switch 320 is maintained in the turn-on state for a certain period of time by the ECU protection unit 350, and is turned on and off by the MCU 310 after a certain period of time. It can be controlled.

As described above, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can prevent back electromotive voltage of a steering motor while implementing fail safety based on a redundant system.

In addition, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can protect the ECU by effectively preventing back electromotive voltage of the steering motor using a simple circuit.

In addition, according to the present disclosure, by using a simpler circuit, it is possible to provide an ECU protection circuit, an electronic control unit, and a steering assistance system that minimizes the space occupied by the device, contributes to high integration, and minimizes the manufacturing cost. there is.

In addition, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that provide driving stability by more stably implementing fail safety.

In addition, according to the present disclosure, the present disclosure can provide an ECU protection circuit, an electronic control unit, and a steering assistance system that can efficiently use the battery by applying a circuit optimized for the dark current of the battery.

The above description and attached drawings merely illustratively illustrate the technical idea of the present disclosure, and those skilled in the art will be able to combine the configurations without departing from the essential characteristics of the present disclosure. , various modifications and transformations such as separation, substitution, and change will be possible. Accordingly, the embodiments disclosed in the present disclosure are not intended to limit the technical idea of the present disclosure but are for illustrative purposes, and the scope of the technical idea of the present disclosure is not limited by these embodiments. That is, within the scope of solving the problem of the present disclosure, all of the components may be selectively combined and operated in one or more pieces. The scope of protection of this disclosure should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of this disclosure.

100: Steering assistance system 110: Battery
120: first electronic control unit 130: second electronic control unit
140: steering motor 150: sensor
160: ECU protection module 200: ECU protection circuit
210: Zeno diode 220: First switch
230: second switch 300: electronic control unit
310: MCU 320: PCO switch
330: supply voltage switch 340: inverter
350: ECU protection unit

Claims (22)

In the ECU (Electronic Controller Unit) protection circuit,
A Zener diode, one end of which is connected to a steering motor and allowing a reverse current to flow when the phase-to-phase voltage of the steering motor is higher than a preset breakdown voltage (Break down voltage);
a first switch, one end of which is connected to the other end of the Zener diode, and which is turned on when the reverse current is applied to allow a first current to flow; and
A second switch, one end of which is connected to the other end of the first switch and turned on when the first current flows, so that the second current flows and the supply voltage of the battery is conducted to the PCO (Phase Cut Off) switch,
The reverse current flows from the steering motor to the Zener diode,
The first current flows from one end of the second switch to the other end of the first switch,
The PCO switch is an ECU protection circuit characterized in that it is turned on when the supply voltage is applied. According to paragraph 1,
The ECU protection circuit, characterized in that the breakdown voltage corresponds to the breakdown voltage of the PCO switch. According to paragraph 1,
The Zener diodes are plural,
An ECU protection circuit characterized in that the plurality of Zener diodes are connected to each phase of the steering motor. According to paragraph 3,
The steering motor is a three-phase motor,
An ECU protection circuit, wherein each of the U-phase, V-phase, and W-phase of the steering motor is connected to one end of each of the plurality of Zener diodes. According to paragraph 1,
The first switch is a transistor including three terminals,
A first terminal of the first switch is connected to the other terminal of the Zeno diode,
The second terminal of the first switch is connected to one end of the second switch,
An ECU protection circuit, characterized in that the third terminal of the first switch is grounded. According to paragraph 1,
The second switch is a transistor including three terminals,
The first terminal of the second switch is connected to the other terminal of the first switch,
The second terminal of the second switch is connected to one end of the PCO switch,
The ECU protection circuit is characterized in that the third terminal of the second switch is connected to the battery. According to paragraph 1,
An ECU protection circuit, wherein the first switch and the second switch are junction transistors (Bipolar Junction Transistor, BJT). In clause 7,
The first switch is an NPN transistor,
An ECU protection circuit wherein the second switch is a PNP transistor. According to paragraph 1,
An ECU protection circuit, wherein the first switch and the second switch are field-effect transistors (FETs). According to clause 9,
The first switch is an NMOS transistor,
An ECU protection circuit wherein the second switch is a PMOS transistor. According to paragraph 1,
The ECU protection circuit further includes a capacitor that modifies the waveform of the supply voltage applied to the PCO switch,
The first terminal of the capacitor is connected between the second switch and the PCO switch,
ECU protection circuit, characterized in that the second terminal of the capacitor is grounded. According to clause 11,
The waveform of the supply voltage includes a rising section, a maintaining section, and a falling section of the supply voltage,
The PCO switch is an ECU protection circuit characterized in that it is turned off after the falling period. A supply voltage switch that turns on the supply voltage of the battery;
An inverter that outputs a control signal to control the operation of the steering motor;
a PCO (Phase Cut Off) switch that conducts the control signal to the steering motor or blocks supply of the control signal;
an MCU (Micro Controller Unit) that controls each of the supply voltage switch, the inverter, and the PCO switch; and
Based on the phase-to-phase voltage of the steering motor, it is determined whether a back electromotive voltage is generated in the steering motor, and when a back electromotive voltage is generated in the steering motor, the supply voltage is conducted to the PCO switch to turn on the PCO switch. Electronic control unit containing ECU protection. According to clause 13,
The supply voltage switch maintains the turn-on state before the counter electromotive voltage is generated,
The PCO switch maintains a turn-off state before the counter electromotive voltage is generated, and is switched to a turn-on state by the ECU protection unit when the counter electromotive voltage occurs. According to clause 14,
The PCO switch is maintained in a turn-on state for a certain period of time by the ECU protection unit, and after the certain period of time, the PCO switch is controlled to be turned on and off by the MCU. According to clause 13,
The ECU protection unit compares the phase-to-phase voltage with a preset reference voltage, and, if the phase-to-phase voltage is greater than the reference voltage, determines that the counter electromotive voltage has occurred. According to clause 16,
The reference voltage is set based on the internal voltage of the PCO switch. A first electronic control unit including a first MCU, a first inverter, and a first PCO switch;
a second electronic control unit including a second MCU, a second inverter, and a second PCO switch;
a battery supplying power to the first electronic control unit and the second electronic control unit;
A single winding steering motor controlled by the first electronic control unit or the second electronic control unit;
When the control right for controlling the steering motor is transitioned between the first electronic control unit and the second electronic control unit, if the phase-to-phase voltage of the steering motor is higher than a preset reference voltage, the control right controls the supply voltage of the battery. A steering assistance system that includes an ECU protection module that applies to the PCO switch included in the transferred electronic control unit. According to clause 18,
A steering assistance system, wherein the reference voltage is the breakdown voltage of a Zener diode included in the ECU protection module. According to clause 18,
The reference voltage is set based on the internal voltage of the PCO switch included in the electronic control unit to which the control right has been transferred. According to clause 18,
The ECU protection module modifies the waveform of the supply voltage and applies it to the PCO switch,
The PCO switch is turned on while the supply voltage is applied. According to clause 21,
The waveform of the supply voltage includes a rising section, a maintaining section, and a falling section of the supply voltage,
The steering assistance system, wherein the PCO switch is controlled on and off by the electronic control unit to which the control right is transferred after the descending section.

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