Electronic control devices and power supply systems

Abstract

The power supply relay unit includes a high-potential-side relay connected with the anode of a parasitic diode facing the high-potential side and the cathode facing the low-potential side; and a low-potential-side relay connected in series with the low-potential side of the high-potential-side relay, with the cathode of the parasitic diode facing the high-potential side and the anode facing the low-potential side. An inter-relay connection line connects the midpoint between the first high-potential-side relay and the first low-potential-side relay, and the midpoint between the second high-potential-side relay and the second low-potential-side relay. The relay control circuit includes a relay driver and a monitoring circuit for monitoring the relay intermediate voltage. The control unit controls the on / off operation of the high-potential-side relay based on the first supply voltage, the second supply voltage, and the relay intermediate voltage.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on Japanese Patent Application No. 2019-227129 filed on December 17, 2019, and the contents thereof are incorporated herein by reference. Technical Field

[0003] The invention relates to an electronic control device and a power supply system. Background Art

[0004] Conventionally, steering systems are known that include two ECUs operated by power supplied from a battery. For example, in Patent Document 1, each ECU is equipped with a power relay that switches power to the drive circuit of its own system on and off, and an auxiliary power relay that switches power to the drive circuit of another system on and off.

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-077832

[0006] In the circuit configuration of Patent Document 1, when regenerative power is high, there is a risk that power exceeding the battery's permitted capacity may be supplied, depending on the on / off timing of the auxiliary power relay. If the power supply is temporarily disconnected before the auxiliary power relay is turned on to prevent excessive power regeneration to the battery, power to the microcomputer is also cut off, necessitating countermeasures against temporary power outages. The present disclosure aims to provide an electronic control device and power supply system that can continue to operate appropriately even when an abnormality occurs in one power source. Summary of the Invention

[0007] An electronic control device of the present disclosure includes a first power supply relay unit, a second power supply relay unit, an inter-relay connection line, a first relay control circuit, a second relay control circuit, and a control unit.

[0008] The first power supply relay unit includes: a first high potential side relay, which is connected so that the anode of the parasitic diode is the high potential side and the cathode is the low potential side; and a first low potential side relay, which is connected in series with the low potential side of the first high potential side relay so that the cathode of the parasitic diode is the high potential side and the anode is the low potential side. The first power supply relay unit is connected to a first external power supply.

[0009] The second power supply relay unit includes: a second high potential side relay, which is connected so that the anode of the parasitic diode is the high potential side and the cathode is the low potential side; and a second low potential side relay, which is connected in series with the low potential side of the second high potential side relay so that the cathode of the parasitic diode is the high potential side and the anode is the low potential side. The second power supply relay unit is connected to a second external power supply different from the first external power supply.

[0010] The inter-relay connection line connects an intermediate point between the first high-potential-side relay and the first low-potential-side relay, and an intermediate point between the second high-potential-side relay and the second low-potential-side relay. The first relay control circuit includes a first relay driver for driving the first high-potential-side relay; a first upper-side monitoring circuit for monitoring a first supply voltage on the high-potential side of the first high-potential-side relay; and a first lower-side monitoring circuit for monitoring a voltage on the inter-relay connection line, i.e., a relay intermediate voltage, on the low-potential side of the first high-potential-side relay.

[0011] The second relay control circuit includes: a second relay driver that drives the second high-potential-side relay; a second upper-side monitoring circuit that monitors the second supply voltage on the high-potential side of the second high-potential-side relay; and a second lower-side monitoring circuit that monitors the relay intermediate voltage on the low-potential side of the second high-potential-side relay.

[0012] The control unit controls the on / off operation of the first high-potential side relay and the second high-potential side relay based on the first supply voltage, the second supply voltage, and the relay intermediate voltage. This allows proper operation to continue even if an abnormality occurs in the first or second external power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above-mentioned objects and other objects, features and advantages of the present disclosure will become more apparent through the following detailed description with reference to the accompanying drawings. The accompanying drawings are:

[0014] Figure 1 This is a schematic configuration diagram showing a steering system according to one embodiment.

[0015] Figure 2 It is a cross-sectional view showing a driving device according to one embodiment.

[0016] Figure 3 yes Figure 2 Cross-sectional view along line III-III.

[0017] Figure 4 is a circuit diagram showing a driving device according to one embodiment.

[0018] Figure 5 This is a circuit diagram illustrating a power supply relay unit according to one embodiment.

[0019] Figure 6 This is a flowchart illustrating a voltage drop determination process according to one embodiment.

[0020] Figure 7 This is a flowchart illustrating the regeneration process according to one embodiment.

[0021] Figure 8This is a flowchart illustrating an initial inspection process according to one embodiment.

[0022] Figure 9 1 is a schematic diagram showing a power supply system according to one embodiment. DETAILED DESCRIPTION

[0023] (One embodiment)

[0024] Hereinafter, an electronic control device according to the present disclosure will be described with reference to the accompanying drawings. Figures 1 to 9 FIG. 1 shows an electronic control device according to an embodiment. Figure 1 As shown, an ECU 10 as an electronic control unit is applied to, for example, an electric power steering device 8 for assisting a steering operation of a vehicle. Figure 1 The structure of a steering system 90 including the electric power steering device 8 is shown. The steering system 90 includes a steering wheel 91 as a steering member, a steering shaft 92, a pinion 96, a rack shaft 97, wheels 98, the electric power steering device 8, and the like.

[0025] The steering wheel 91 is connected to the steering shaft 92. A torque sensor 94 is installed on the steering shaft 92 to detect steering torque. The torque sensor 94 includes a first sensor portion 194 and a second sensor portion 294, each capable of detecting its own failure. A pinion 96 is installed at the front end of the steering shaft 92. The pinion 96 meshes with a rack shaft 97. A pair of wheels 98 are connected to both ends of the rack shaft 97 via tie rods and other means.

[0026] When the driver rotates the steering wheel 91, the steering shaft 92 connected to the steering wheel 91 rotates. The rotational motion of the steering shaft 92 is converted into linear motion of the rack shaft 97 by the pinion 96. The pair of wheels 98 are steered to an angle corresponding to the displacement of the rack shaft 97.

[0027] The electric power steering system 8 includes a drive unit 40 and a reduction gear 89. The drive unit 40 includes a motor 80 and an ECU 10. The reduction gear 89, serving as a power transmission unit, reduces the speed of the motor 80 and transmits it to the steering shaft 92. That is, the electric power steering system 8 of this embodiment is a so-called "column-assisted type," but it may also be a so-called "rack-assisted type" that transmits the rotation of the motor 80 to the rack shaft 97. In this embodiment, the steering shaft 92 can be said to be the "driven object."

[0028] like Figures 2 to 4 As shown, the motor 80 outputs part or all of the torque required for steering and is driven by power supplied from batteries 191, 291 as external power sources to rotate the reduction gear 89 forward and reverse. The motor 80 is a three-phase brushless motor, but other motors may be used.

[0029] The motor 80 includes a first motor winding 180 and a second motor winding 280 as winding groups. The motor windings 180 and 280 have the same electrical characteristics and are wound around a common stator 840 (see Figure 2 ). Correspondingly, the phase current of the motor windings 180 and 280 is controlled to be offset by 30[deg] in the energizing phase φ. By optimizing the energizing phase difference, the output torque is improved. In addition, the 6th-order torque pulsation can be reduced, and the noise and vibration can be reduced. In addition, since the current is also dispersed and the heat is dispersed and balanced, the temperature-dependent inter-system errors of the detection values ​​of each sensor, torque, etc. can be reduced, and the amount of current that can be energized can be increased. In addition, the motor windings 180 and 280 may not be offset windings, and the electrical characteristics may also be different.

[0030] Hereinafter, the combination of the first inverter 120 and the first control unit 170 involved in the power supply control of the first motor winding 180 is referred to as the first system L1, and the combination of the second inverter 220 and the second control unit 270 involved in the power supply control of the second motor winding 280 is referred to as the second system L2. In addition, the components involved in the first system L1 are mainly numbered in the 100 segment, and the components involved in the second system L2 are mainly numbered in the 200 segment. In addition, in the first system L1 and the second system L2, the last two digits of the same number are used for the same or similar components, and the description of the components of the second system L2 is appropriately omitted. Hereinafter, "first" is appropriately described by adding "1" and "second" is appropriately described by adding "2".

[0031] The drive device 40 is integrally provided with the ECU 10 on one side of the motor 80 in the axial direction, creating a so-called "mechatronic" design. However, the motor 80 and ECU 10 may also be provided separately. The ECU 10 is located coaxially with the axis Ax of the shaft 870 on the side opposite the output shaft of the motor 80. The ECU 10 may also be provided on the output shaft side of the motor 80. The mechatronic design allows for efficient placement of the ECU 10 and motor 80 in vehicles with limited mounting space.

[0032] The motor 80 includes a stator 840, a rotor 860, and a housing 830 that accommodates them. The stator 840 is fixed to the housing 830 and is wound with motor windings 180 and 280. The rotor 860 is provided radially inside the stator 840 and is rotatable relative to the stator 840.

[0033] Shaft 870 is embedded in rotor 860 and rotates integrally with rotor 860. Shaft 870 is rotatably supported by housing 830 via bearings 835 and 836. The end of shaft 870 on the ECU 10 side protrudes from housing 830 toward the ECU 10. A magnet 875, which serves as a detection target, is provided at the end of shaft 870 on the ECU 10 side. The center of magnet 875 is located on axis Ax.

[0034] The housing 830 includes a bottomed cylindrical casing 834 including a rear frame end 837, and a front frame end 838 provided on the open side of the casing 834. The casing 834 and the front frame end 838 are fastened to each other by bolts or the like. Lead wire insertion holes 839 are formed in the rear frame end 837. Lead wires 185 and 285 connected to the respective phases of the motor windings 180 and 280 are inserted into the lead wire insertion holes 839. The leads 185 and 285 are led out from the lead wire insertion holes 839 to the ECU 10 side and connected to the substrate 470.

[0035] ECU10 includes a cover 460, a heat sink 465 fixed to the cover 460, a substrate 470 fixed to the heat sink 465, and various electronic components mounted on the substrate 470. The cover 460 protects the electronic components from external impacts or prevents dust, water, etc. from penetrating into the interior of the ECU10. A cover body 461 and a connector part 462 are integrally formed in the cover 460. The connector part 462 can also be separated from the cover body 461. The terminal 463 of the connector part 462 is connected to the substrate 470 via wiring, etc., not shown in the figure. The number of connectors and the number of terminals can be appropriately changed according to the number of signals, etc. The connector part 462 is provided at the axial end of the drive device 40 and opens on the side opposite to the motor 80.

[0036] The substrate 470 is, for example, a printed circuit board and is disposed opposite the rear frame end 837. Two systems of electronic components are independently mounted on the substrate 470. In this embodiment, the electronic components are mounted on a single substrate 470, but the electronic components may be mounted on multiple substrates.

[0037] Of the two main surfaces of the substrate 470, the surface on the motor 80 side is referred to as the motor surface 471, and the surface opposite to the motor 80 is referred to as the cover surface 472. Figure 3 As shown, the switching elements 121 to 126 constituting the first inverter 120 , the switching elements 221 to 226 constituting the second inverter 220 , the angle sensors 134 and 234 , the custom ICs 171 and 271 , and the like are mounted on the motor surface 471 .

[0038] The custom ICs 171 and 271 are provided with boost circuits 160 and 260 (see Figure 4), amplifier circuits, and pre-drivers. The boosted voltage of boost circuits 160 and 260 is higher than supply voltages Vb1 and Vb2 and is used as the gate voltage for high-potential switching elements 121 to 123 and 221 to 223. Angle sensors 134 and 234 are mounted opposite magnet 875 to detect changes in the magnetic field associated with magnet 875's rotation.

[0039] The inductors 145, 245, the capacitors 146, 147, 246, 247, and the microcomputers constituting the control units 170, 270 are mounted on the cover surface 472. Figure 3 In the example, the microcomputers constituting the control units 170 and 270 are numbered "170" and "270" respectively. Figure 3 Although not shown in the figure, the motor relays 127 to 129 , 227 to 229 , the current detection elements 131 to 133 , 231 to 233 , the relays 141 , 142 , 241 , 242 , etc. are also mounted on the motor surface 471 or the cover surface 472 .

[0040] like Figure 4 as well as Figure 5 As shown, the ECU 10 includes inverters 120, 220, power supply relay units 140, 240, and control units 170, 270. The first control unit 170 controls the energization of the first motor winding 180, while the second control unit 270 controls the energization of the second motor winding 280. In this embodiment, a fully redundant configuration is formed in which the first system L1 and the second system L2 are independently provided.

[0041] The control units 170 and 270 are primarily composed of a microcomputer or the like, and internally include a CPU, ROM, RAM, I / O, and a bus connecting these components (all not shown). Each process in the control units 170 and 270 can be software processing, where the CPU executes a program pre-stored in a physical memory device such as ROM (i.e., a readable, non-transitory, tangible storage medium), or hardware processing using dedicated electronic circuits. In the figures, the control units 170 and 270 are appropriately referred to as "microcomputers."

[0042] The first inverter 120 is a three-phase inverter, and the first switching elements 121 to 126 are bridge-connected. The switching elements 121 to 123 are connected to the high potential side, and the switching elements 124 to 126 are connected to the low potential side. The connection point of the paired U-phase switching elements 121 and 124 is connected to one end of the first U-phase coil 181, the connection point of the paired V-phase switching elements 122 and 125 is connected to one end of the first V-phase coil 182, and the connection point of the paired W-phase switching elements 123 and 126 is connected to one end of the first W-phase coil 183. The other ends of the coils 181 to 183 are connected. A first current detection unit 130 for detecting the current of the coils 181 to 183 is provided on the low potential side of the switching elements 124 to 126. The first current detection unit 130 includes current detection elements 131 to 133.

[0043] The second inverter 220 is a three-phase inverter, and the second switching elements 221 to 226 are bridge-connected. The switching elements 221 to 223 are connected to the high potential side, and the switching elements 224 to 226 are connected to the low potential side. The connection point of the paired U-phase switching elements 221 and 224 is connected to one end of the second U-phase coil 281, the connection point of the paired V-phase switching elements 222 and 225 is connected to one end of the first V-phase coil 282, and the connection point of the paired W-phase switching elements 223 and 226 is connected to one end of the first W-phase coil 283. The other ends of the coils 281 to 283 are connected. A second current detection unit 230 for detecting the current of the coils 281 to 283 is provided on the low potential side of the switching elements 224 to 226. The second current detection unit 230 is provided with current detection elements 231 to 233. The current detection elements 131 to 133 and 231 to 233 in this embodiment are shunt resistors, but other elements such as Hall elements can also be used.

[0044] First motor relays 127-129 are provided between first inverter 120 and first motor winding 180, and are configured to disconnect and connect first inverter 120 and first motor winding 18. U-phase motor relay 127 is provided between the connection point of switching elements 121 and 124 and U-phase coil 181, V-phase motor relay 128 is provided between the connection point of switching elements 122 and 125 and V-phase coil 182, and W-phase motor relay 129 is provided between the connection point of switching elements 123 and 126 and W-phase coil 183.

[0045] Second motor relays 227-229 are provided between second inverter 220 and second motor winding 280, and are configured to disconnect and connect second inverter 220 and second motor winding 280. U-phase motor relay 227 is provided between the connection point of switching elements 221 and 224 and U-phase coil 281, V-phase motor relay 228 is provided between the connection point of switching elements 222 and 225 and V-phase coil 282, and W-phase motor relay 229 is provided between the connection point of switching elements 223 and 226 and W-phase coil 283.

[0046] A first power supply relay unit 140 is provided on the high-potential side wiring Lp1 that connects the positive electrode of the first battery 191 to the high-potential side of the first inverter 120. The first power supply relay unit 140 includes a first power supply relay 141 and a first reverse connection protection relay 142. In this embodiment, the relays 141 and 142 are MOSFETs and have parasitic diodes. Therefore, the two elements are connected in series so that the parasitic diodes of the relays 141 and 142 face opposite directions. This prevents reverse current flow in the event that the first battery 191 is mistakenly connected in reverse. The power supply relay units 140 and 240 will be described in detail later.

[0047] The first switching elements 121-126, first motor relays 127-129, power supply relay 141, and reverse polarity protection relay 142 are controlled for on / off operation based on control signals from the first control unit 170. The second switching elements 221-226, second motor relays 227-229, power supply relay 241, and reverse polarity protection relay 242 are controlled for on / off operation based on control signals from the second control unit 270. To avoid cumbersomeness, some control lines are omitted in the figure.

[0048] The inductor 145 is provided between the first battery 191 and the first power supply relay unit 140. The positive electrode of the capacitor 146 is connected between the first battery 191 and the inductor 145, and the negative electrode is connected to the common ground Gc. The inductor 145 and the capacitor 146 constitute a filter circuit to reduce noise transmitted from other devices that share the first battery 191, and reduce noise transmitted from the drive device 40 to other devices that share the first battery 191. The positive electrode of the capacitor 147 is connected between the power supply relay unit 140 and the first inverter 120, and the negative electrode is connected to the common ground Gc. The Zener diode 148 (see Figure 5 ) has a cathode connected between the power supply relay unit 140 and the first inverter 120, and an anode connected to the common ground Gc. The capacitor 147 and the Zener diode 148 smooth the power supplied to the first inverter 120.

[0049] A second inverter 220 is connected to the second motor winding 280, and power is supplied from a second battery 291 via the second inverter 220. The second inverter 220 includes switching elements 221 to 226. A second current detection unit 230 including current detection elements 231 to 233 is provided on the low-potential side of the second inverter 220. Motor relays 236 to 238 are also provided between the second inverter 220 and the second motor winding 280.

[0050] The second power supply relay unit 240 is provided on the high potential side wiring Lp2 that connects the positive electrode of the second battery 291 to the high potential side of the second inverter 220. The inductor 245 is provided between the second battery 291 and the second power supply relay unit 240. The positive electrode of the capacitor 246 is connected between the second battery 291 and the inductor 245, and the negative electrode is connected to the common ground Gc. In addition, the positive electrode of the capacitor 247 is connected between the power supply relay unit 240 and the second inverter 220, and the negative electrode is connected to the common ground Gc. The Zener diode 248 (see Figure 5 ) is connected between the power supply relay unit 240 and the second inverter 220, and the anode is connected to the common ground Gc. The details of the functions of each component are the same as those of the first system. Figure 5 In FIG, the battery terminal of the first system L1 is described as B1, the ground terminal is described as G1, the battery terminal of the second system L2 is described as B2, and the ground terminal is described as G2.

[0051] like Figure 5 As shown, the first power supply relay 141 and the first reverse polarity protection relay 142 are connected in a "drain-common" configuration, with the drain facing inward and the source facing outward. The anode of the parasitic diode faces outward, and the cathode faces inward. Similarly, the second power supply relay 241 and the second reverse polarity protection relay 242 are connected in a "drain-common" configuration, with the drain facing inward and the source facing outward. The anode of the parasitic diode faces outward, and the cathode faces inward. This drain-common configuration allows for a common lead frame and chip, and by separating the source from the chip, further miniaturization is possible compared to a source-common configuration.

[0052] In this embodiment, the first reverse polarity protection relay 142 is provided on the first battery 191 side, and the first power supply relay 141 is provided on the first system circuit C1 side. In addition, the second reverse polarity protection relay 242 is provided on the second battery 291 side, and the second power supply relay 241 is provided on the second system circuit C2 side. The first system circuit C1 includes the first inverter 120 and the first control unit 170 connected to the downstream side of the first power supply relay unit 140, but for the sake of explanation, Figure 5 , the first control unit 170 and the first monitoring circuit 173 are described as blocks separate from the first system circuit C1 . The same applies to the second system circuit C2 .

[0053] In this embodiment, the intermediate point M1 between the first power supply relay 141 and the first reverse polarity protection relay 142 and the intermediate point M2 between the second power supply relay 241 and the second reverse polarity protection relay 242 are connected by the inter-relay connection line 300. Therefore, the relay intermediate voltage Vbc is the same in the systems L1 and L2.

[0054] A first power supply relay control circuit 150 is provided for the first power supply relay 141, and a second power supply relay control circuit 250 is provided for the second power supply relay 241. The first power supply relay control circuit 150 includes a first power supply relay driver 151 and voltage monitoring circuits 152 and 153. The second power supply relay control circuit 250 includes a second power supply relay driver 251 and voltage monitoring circuits 252 and 253.

[0055] The first power supply relay driver 151 outputs a gate signal to the first power supply relay 141 based on a control signal from the first control unit 170, thereby switching the first power supply relay 141 on and off. The second power supply relay driver 251 outputs a gate signal to the second power supply relay 241 based on a control signal from the second control unit 270, thereby switching the second power supply relay 241 on and off.

[0056] Voltage monitoring circuits 152, 153, 252, and 253 are, for example, voltage-dividing resistors. Voltage monitoring circuit 152 detects relay intermediate voltage Vbc and outputs it to first control unit 170. Voltage monitoring circuit 153 detects relay downstream voltage Vr1 and outputs it to first monitoring circuit 173. Voltage monitoring circuit 252 detects relay intermediate voltage Vbc and outputs it to second control unit 270. Voltage monitoring circuit 253 detects relay downstream voltage Vr2 and outputs it to second monitoring circuit 273.

[0057] A first supply regeneration control circuit 155 is provided corresponding to the first reverse polarity protection relay 142, and a second supply regeneration control circuit 255 is provided corresponding to the second reverse polarity protection relay 242. The first supply regeneration control circuit 155 includes a first reverse polarity protection relay driver 156 and voltage monitoring circuits 157 and 158. The second supply regeneration control circuit 255 includes a second reverse polarity protection relay driver 256 and voltage monitoring circuits 257 and 258.

[0058] The first reverse polarity protection relay driver 156 outputs a gate signal to the first reverse polarity protection relay 142 based on a control signal from the first control unit 170, thereby switching the first reverse polarity protection relay 142 on and off. The second reverse polarity protection relay driver 256 outputs a gate signal to the second reverse polarity protection relay 242 based on a control signal from the second control unit 270, thereby switching the second reverse polarity protection relay 242 on and off.

[0059] Voltage monitoring circuits 157, 158, 257, and 258 are, for example, voltage-dividing resistors. Voltage monitoring circuit 157 detects a first supply voltage Vb1 and outputs it to first control unit 170. Voltage monitoring circuit 158 ​​detects a relay intermediate voltage Vbc and outputs it to first control unit 170. Voltage monitoring circuit 257 detects a second supply voltage Vb2 and outputs it to second control unit 270. Voltage monitoring circuit 258 detects a relay intermediate voltage Vbc and outputs it to second control unit 270. First supply voltage Vb1 is the voltage supplied from first battery terminal B1 connected to first battery 191, and second supply voltage Vb2 is the voltage supplied from second battery terminal B2 connected to second battery 291.

[0060] The booster circuits 160 and 260 are connected to the inter-relay connection line 300. Since only one of the booster circuits 160 and 260 needs to be connected to the inter-relay connection line 300, the following description assumes that the booster circuit 160 of the first system L1 is connected to the inter-relay connection line 300. Furthermore, the boosted voltage of the booster circuit 160 is simply referred to as the boosted voltage Vu, omitting the "1" indicating the system.

[0061] The boost circuit 160 is connected to the inter-relay connection line 300 via a boost switch 161 and a resistor 162. The boost switch 161 is controlled by the first control unit 170 to open and close, switching between the boost circuit 160 and the inter-relay connection line 300. The boost switch 161 can be either a semiconductor relay or a mechanical relay. The resistance value of the resistor 162 is set to limit the current from the boost circuit 160 to the inter-relay connection line 300 when the boost switch 161 is closed. The boost switch 161 is turned on during the initial check and when the internal voltage decreases. Details of the initial check will be described later.

[0062] In this embodiment, the parasitic diodes of the reverse polarity protection relays 142 and 242, located on the battery 191 and 291 sides, are designed to allow current to flow from the high-potential side to the low-potential side. Furthermore, an inter-relay connection line 300 connects the midpoint M1 of the relays 141 and 142 to the midpoint M2 of the relays 241 and 242. This allows power to be supplied from the second battery 291 to the first system L1 via the inter-relay connection line 300 without stopping the first and second system circuits C1 and C2. Furthermore, even if a power supply abnormality such as a voltage drop occurs in the second system L2, power can be supplied from the first battery 191 to the second system L2 via the inter-relay connection line 300 without stopping the first and second system circuits C1 and C2. Here, power supply abnormalities in the first system L1 are not limited to abnormalities in the first battery 191 itself but also include wiring abnormalities. The same applies to power supply abnormalities in the second system L2.

[0063] based on Figure 6 The flowchart in FIG. 1 illustrates the voltage drop determination process of this embodiment. This process is executed by control units 170 and 270 at a predetermined cycle when the vehicle's starter switch, such as the ignition switch, is turned on. Necessary information is shared between control units 170 and 270 through inter-microcomputer communication or other means. Hereinafter, step S101 will be omitted as "step" and simply indicated by the symbol "S." Furthermore, both systems L1 and L2 are supplied with supply voltages Vb1 and Vb2 within the normal range, and power supply relays 141 and 241 are turned on.

[0064] In S101, the control units 170 and 270 determine whether a voltage drop has occurred. In this embodiment, if equation (1) holds true, a voltage drop is determined to have occurred in the first system L1, and if equation (2) holds true, a voltage drop is determined to have occurred in the second system L2. Vth1 and Vth2 in the equations are voltage drop determination values, set based on the voltage drop across the reverse polarity protection relays 142 and 242.

[0065] Vbc-Vth1>Vb1···(1)

[0066] Vbc-Vth2>Vb2···(2)

[0067] If it is determined that a voltage drop has not occurred in either system L1 or L2 ( S101 : No), the process from S102 onwards is skipped. If it is determined that a voltage drop has occurred in either system L1 or L2 ( S101 : Yes), the process proceeds to S102. Hereinafter, the system experiencing a voltage drop is referred to as a voltage drop system, and the system without a voltage drop is referred to as a normal system.

[0068] In S102, the control units 170 and 270 open the reverse connection protection relays 142 and 242 of the voltage drop system. Specifically, if a voltage drop occurs in the first system L1, the reverse connection protection relay 142 is opened, and if a voltage drop occurs in the second system L2, the reverse connection protection relay 242 is opened. This disconnects the power supply system of the voltage drop system. Power continues to be supplied from the normal system to the voltage drop system via the inter-relay connection line 300 without being interrupted.

[0069] In S103, the control units 170 and 270 determine whether the voltage drop system has been in a state where a voltage drop has occurred for a period of time exceeding the abnormality determination time Xth. In this embodiment, an abnormality determination is made if the state in which equation (3) holds true continues for a period of time exceeding the abnormality determination time Xth. Vthe in equation (3) is arbitrarily set based on the value permitted as a voltage drop. The # in the equation represents the system, and is "1" if the voltage drop system is the first system L1, and "2" if it is the second system L2.

[0070] (Vbc-Vth#)-Vb#>Vthe···(3)

[0071] If it is determined that the voltage drop has occurred for less than the abnormality determination time Xth (S103: No), the reverse polarity protection relay of the voltage drop system remains disconnected, and power supply from the normal system to both systems continues. If it is determined that the voltage drop has occurred for more than the abnormality determination time Xth (S103: Yes), the process proceeds to S104.

[0072] In S104, control units 170 and 270 determine that a power anomaly exists in the voltage drop system and, for example, illuminate a warning light on the instrument panel to alert the user of the power anomaly. This warning may be provided by a sound or other means other than illuminating a warning light. This encourages the user to take the vehicle to a dealer or repair shop.

[0073] In this embodiment, when a voltage drop occurs in one system, the reverse polarity protection relay in the voltage drop system is opened, allowing power to be supplied from the normal system to both systems. If a large amount of regenerative power is generated, and power exceeding the allowable amount is supplied to the normal system's power supply system, there is a risk of damaging the normal system's battery. Therefore, in this embodiment, the reverse polarity protection relays 142 and 242 are controlled on and off based on the relay intermediate voltage Vbc to protect the circuit.

[0074] based on Figure 7The flowchart in FIG201 illustrates the regeneration processing of this embodiment. This processing is executed by the control unit 170, 270 at a predetermined cycle when the regeneration voltage is generated. In S201, the control unit 170, 270 determines whether the relay intermediate voltage Vbc is greater than the regeneration determination value Vthr. The regeneration determination value Vthr is set to an arbitrary value that is greater than the normal upper limit of the power supply voltage and less than the minimum withstand voltage of the circuit components. If the relay intermediate voltage Vbc is determined to be greater than the regeneration determination value Vthr (S201: Yes), the process proceeds to S202. If the relay intermediate voltage Vbc is determined to be less than the regeneration determination value Vthr (S201: No), the process proceeds to S203.

[0075] In S202, the control units 170 and 270 turn on the reverse polarity protection relays 142 and 242 of the two systems, regenerating power to the batteries 191 and 291 of the two systems. Specifically, even if the reverse polarity protection relays of the voltage drop system are turned off, if excessive regeneration occurs, the reverse polarity protection relays 142 and 242 of the two systems are turned on to regenerate power to the voltage drop system, thereby preventing excessive regeneration to the normal system.

[0076] In S203, the control units 170 and 270 continue the on and off states of the reverse connection protection relays 142 and 242 according to the voltage drop. When one reverse connection protection relay is turned off due to the voltage drop, regenerative power is regenerated to the normal system side.

[0077] In the present embodiment, the inter-relay connection line 300 is configured so that a boosted voltage higher than the supply voltages Vb1 and Vb2 can be applied from the booster circuit 160. This allows for an initial inspection of the power supply relay units 140 and 240.

[0078] based on Figure 8 The flowchart of FIG. 1 illustrates the initial inspection process of this embodiment. This process is executed by the control unit 170, 270 when the start switch of the vehicle is turned on. Figure 8 In FIG. 1 , the first reverse polarity protection relay 142 is described as “MOSr1”, and the second reverse polarity protection relay 242 is described as “MOSr2”.

[0079] In S301, the control units 170 and 270 disconnect all components of the power supply relay units 140 and 240, namely, the power supply relays 141 and 241 and the reverse polarity protection relays 142 and 242. Furthermore, the control units 170 and 270 turn on the boost switch 161 to apply a boost voltage Vu to the inter-relay connection line 300. In this embodiment, a resistor 162 is provided between the boost circuit 160 and the inter-relay connection line 300, and the boost voltage Vu is applied to the inter-relay connection line 300 in a current-limited state. Current limiting may also be achieved by a configuration different from the resistor 162. Furthermore, when a boost circuit, a boost switch, and a resistor are provided for each system, the control units 170 and 270 may also control the boost switch of the system concerned.

[0080] In S302, control units 170 and 270 determine whether relay intermediate voltage Vbc is equal to boost voltage Vu. Here, if relay intermediate voltage Vbc is within the normal determination range that includes boost voltage Vu, relay intermediate voltage Vbc and boost voltage Vu are considered equal. The determinations in S305 and S306 are similar. The normal determination range can be set as appropriate. If relay intermediate voltage Vbc is determined to be different from boost voltage Vu (S302: No), the process proceeds to S309 to perform abnormality handling. If relay intermediate voltage Vbc is determined to be equal to boost voltage Vu (S302: Yes), the process proceeds to S303.

[0081] In S303, the control unit 170 turns off the boost switch 161. In S304, the control unit 170 turns on the first reverse connection protection relay 142. At this time, the second reverse connection protection relay 242 remains off.

[0082] In S305, control units 170 and 270 determine whether relay intermediate voltage Vbc is equal to first supply voltage Vb1. If relay intermediate voltage Vbc is determined to be different from first supply voltage Vb1 (S305: No), the process proceeds to S309 to perform abnormality handling. If relay intermediate voltage Vbc is determined to be equal to first supply voltage Vb1 (S305: Yes), the process proceeds to S306. In S306, first control unit 170 turns off first reverse polarity protection relay 142, and second control unit 270 turns on second reverse polarity protection relay 242.

[0083] In S307, control units 170 and 270 determine whether relay intermediate voltage Vbc is equal to second supply voltage Vb2. If relay intermediate voltage Vbc is determined to be different from second supply voltage Vb2 (S307: No), the process proceeds to S309 to perform abnormality handling. If relay intermediate voltage Vbc is determined to be equal to second supply voltage Vb2 (S307: Yes), the process proceeds to S308 to determine that reverse polarity protection relays 142 and 242 are functioning normally.

[0084] The processing of S304 and S305 and the processing of S306 and S307 may be performed in a different order. Alternatively, the first control unit 170 may perform the determination processing of S305 and the second control unit 270 may perform the determination processing of S307.

[0085] An initial check to confirm that the power relays 141 and 241 are functioning properly is performed separately. Furthermore, during normal operation, the current, drain-source voltage, and component overheating of the first power relay 141 are monitored. If an abnormality is detected, the first power relay 141 is opened, and operation in the second system L2 continues. Furthermore, during normal operation, the current, drain-source voltage, and component overheating of the second power relay 241 are monitored. If an abnormality is detected, the second power relay 241 is opened, and operation in the first system L1 continues.

[0086] According to the above, the ECU 10 becomes a "redundant unit" of two systems, wherein the first system L1 is connected to the first battery 191 and the second system L2 is connected to the second battery 291. Figure 9 As shown, a redundant power supply network is formed by connecting multiple redundant units to batteries 191 and 291. For example, when redundant unit RU1 is an electric power steering device and redundant unit RU2 is an electric brake device, the redundant units are different devices.

[0087] exist Figure 9 In the illustrated power supply system 501 , the plurality of redundant units RU1 to RUn are connected in parallel by connecting the first battery terminal B1 to the first battery 191 and the second battery terminal B2 to the second battery 291 .

[0088] As described above, the ECU 10 of the present embodiment includes the first power supply relay unit 140 , the second power supply relay unit 240 , the inter-relay connection line 300 , the first supply regeneration control circuit 155 , the second supply regeneration control circuit 255 , and the control units 170 , 270 .

[0089] The first power supply relay unit 140 includes: a first reverse polarity protection relay 142, which is connected so that the anode of the parasitic diode is on the high potential side and the cathode is on the low potential side; and a first power supply relay 141, which is connected in series with the low potential side of the first reverse polarity protection relay 142 so that the cathode of the parasitic diode is on the high potential side and the anode is on the low potential side. The first power supply relay unit 140 is connected to the first battery 191.

[0090] The second power supply relay unit 240 includes a second reverse polarity protection relay 242 connected with the anode of a parasitic diode facing the high potential side and the cathode facing the low potential side, and a second power supply relay 241 connected in series with the low potential side of the second reverse polarity protection relay 242 with the cathode of the parasitic diode facing the high potential side and the anode facing the low potential side. The second power supply relay unit 240 is connected to a second battery 291. An inter-relay connection line 300 connects an intermediate point M1 between the first reverse polarity protection relay 142 and the first power supply relay 141, and an intermediate point M2 between the second reverse polarity protection relay 242 and the second power supply relay 241.

[0091] The first supply regeneration control circuit 155 includes a first reverse polarity protection relay driver 156 and voltage monitoring circuits 157 and 158. The first reverse polarity protection relay driver 156 drives the first reverse polarity protection relay 142. The voltage monitoring circuit 157 monitors the first supply voltage Vb1 on the high-potential side of the first reverse polarity protection relay 142. The voltage monitoring circuit 158 ​​monitors the voltage of the inter-relay connection line 300, that is, the relay intermediate voltage Vbc, on the low-potential side of the first reverse polarity protection relay 142.

[0092] The second supply regeneration control circuit 255 includes a second reverse polarity protection relay driver 256 and voltage monitoring circuits 257 and 258. The second reverse polarity protection relay driver 256 drives the second reverse polarity protection relay 242. The voltage monitoring circuit 257 monitors the second supply voltage Vb2 on the high potential side of the second reverse polarity protection relay 242. The voltage monitoring circuit 258 monitors the relay intermediate voltage Vbc on the low potential side of the second reverse polarity protection relay 242.

[0093] The control units 170 and 270 control the on / off operation of the reverse polarity protection relays 142 and 242 based on the first supply voltage Vb1, the second supply voltage Vb2, and the relay intermediate voltage Vbc. In this embodiment, the reverse polarity protection relays 142 and 242 are connected to the power supply relays 141 and 241 by an inter-relay connection line 300. Therefore, even if a malfunction occurs in one of the batteries 191 and 291, power can continue to be supplied to both systems from the other, functioning battery 191 and 291. This ensures that even if a malfunction occurs in one of the batteries 191 and 291, proper operation can continue.

[0094] The inter-relay connection line 300 is connected to a boost circuit 160, capable of supplying a higher voltage than the batteries 191 and 291, via a boost switch 161 and a resistor 162. When the boosted voltage Vu from the boost circuit 160 is applied to the inter-relay connection line 300 with all relay elements of the power supply relay units 140 and 240 disconnected, if the relay intermediate voltage Vbc and the boosted voltage Vu do not match, the control units 170 and 270 determine an abnormality. As described above, a difference in the degree of error is tolerated, and if the difference is within the normal determination range, it is considered to be consistent. This allows for appropriate determination of whether the reverse polarity protection relays 142 and 242 are functioning properly.

[0095] If the first supply voltage Vb1 is determined to be abnormal based on the first supply voltage Vb1 and the relay intermediate voltage Vbc, the control unit 170 opens the first reverse polarity protection relay 142. If the second supply voltage Vb2 is determined to be abnormal based on the second supply voltage Vb2 and the relay intermediate voltage Vbc, the control unit 270 opens the second reverse polarity protection relay 242. This allows the power supply system on the abnormal side to be shut off while power continues to be supplied to the downstream side of the power supply relay units 140 and 240.

[0096] The first or second reverse polarity protection relay 142, which has been disconnected due to a supply voltage abnormality, serves as an abnormal system relay. When regenerative power is generated and the relay intermediate voltage Vbc exceeds the regeneration threshold value Vthr, the control units 170 and 270 close the abnormal system relay. This prevents battery damage due to excessive regeneration on the normal side by regenerating both batteries 191 and 291 when relatively large amounts of regenerative power are generated.

[0097] The power supply system 501 includes redundant units RU1 to Run, each of which has an ECU 10, a first battery 191, and a second battery 291. The redundant units RU1 to Run are connected in parallel to the batteries 191 and 291. This allows power to be appropriately supplied from the two batteries 191 and 291 to the redundant units RU1 to RUn.

[0098] In this embodiment, the ECU 10 corresponds to the "electronic control unit," the first power supply relay 141 corresponds to the "first low-potential relay," the first reverse polarity protection relay 142 corresponds to the "first high-potential relay," the second power supply relay 241 corresponds to the "second low-potential relay," and the second reverse polarity protection relay 242 corresponds to the "second high-potential relay." Furthermore, the first supply regeneration control circuit 155 corresponds to the "first relay control circuit," the first reverse polarity protection relay driver 156 corresponds to the "first relay driver," the voltage monitoring circuit 157 corresponds to the "first upper-side monitoring circuit," and the voltage monitoring circuit 158 ​​corresponds to the "first lower-side monitoring circuit." The second supply regeneration control circuit 255 corresponds to the "second relay control circuit," the second reverse polarity protection relay driver 256 corresponds to the "second relay driver," the voltage monitoring circuit 257 corresponds to the "second upper-side monitoring circuit," and the voltage monitoring circuit 258 corresponds to the "second lower-side monitoring circuit."

[0099] The boost switch 161 corresponds to a "switch," and the resistor 162 corresponds to a "current limiting circuit." Furthermore, the first battery 191 corresponds to a "first external power source," and the second battery 291 corresponds to a "second external power source."

[0100] (Other embodiments)

[0101] In the above embodiment, the first and second systems are connected to a common ground. In other embodiments, the ground for the first and second systems may be separate. Furthermore, in the above embodiment, the first system circuit C1 is provided downstream of the first power relay unit, and the second system circuit C2 is provided downstream of the second power relay unit. In other embodiments, the circuits downstream of the first power relay unit and the second power relay unit may be a single system. Even if the configuration below the power relay unit is a single system, continued operation is possible even in the event of a power system abnormality.

[0102] In the above embodiment, a resistor is used as the current limiting circuit for limiting the current from the boost circuit to the inter-relay connection line. In other embodiments, the current limiting circuit may be formed using elements other than resistors.

[0103] In the above embodiment, two motor windings, two inverter units, and two control units are provided. In other embodiments, the number of motor windings, two inverter units, and two control units may be different, for example, by providing one control unit for multiple motor windings and two inverter units, or by providing one control unit for multiple inverter units and two motor windings.

[0104] In the above embodiment, the motor is a three-phase brushless motor. In other embodiments, devices other than motors and three-phase brushless motors may be used. In addition, it may be a so-called motor generator that also functions as a generator. In addition, the load may be a load other than a motor. In the above embodiment, the electronic control unit and the power supply system are applied to an electric power steering device. In other embodiments, the electronic control unit and the power supply system may be applied to steering control devices other than electric power steering devices such as steer-by-wire devices that are responsible for steering control. In addition, it may be applied to vehicle-mounted devices other than steering control devices, or devices other than vehicle-mounted devices, and the structure on the downstream side of the power relay part may be a circuit structure different from the motor winding and inverter involved in the motor drive.

[0105] The control unit and method thereof described in the present disclosure may also be implemented by a special-purpose computer provided by a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and method thereof described in the present disclosure may also be implemented by a special-purpose computer provided by a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and method thereof described in the present disclosure may also be implemented by one or more special-purpose computers composed of a combination of a processor and a memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored as an instruction executed by a computer in a computer-readable non-transient tangible recording medium. As described above, the present disclosure is not limited to any of the above-mentioned embodiments and can be implemented in various forms without departing from its main purpose.

[0106] The present disclosure has been described based on embodiments. However, the present disclosure is not limited to these embodiments and configurations. The present disclosure also encompasses various modifications and equivalent variations. Furthermore, various combinations and configurations, even those containing only one element, or other combinations and configurations with greater or lesser amounts, are also within the scope and spirit of the present disclosure.

Claims

1. An electronic control device comprising: The first power supply relay unit includes: a first high-potential-side relay connected such that the anode of the parasitic diode is on the high-potential side and the cathode is on the low-potential side; and a first low-potential-side relay connected in series with the low-potential side of the first high-potential-side relay such that the cathode of the parasitic diode is on the high-potential side and the anode is on the low-potential side, wherein the first power supply relay unit is connected to a first external power supply; a second power supply relay unit comprising: a second high-potential-side relay connected such that the anode of the parasitic diode is on the high-potential side and the cathode is on the low-potential side; and a second low-potential-side relay connected in series with the low-potential side of the second high-potential-side relay such that the cathode of the parasitic diode is on the high-potential side and the anode is on the low-potential side, the second power supply relay unit being connected to a second external power supply different from the first external power supply; an inter-relay connection line connecting a midpoint between the first high-potential side relay and the first low-potential side relay, and a midpoint between the second high-potential side relay and the second low-potential side relay; The first relay control circuit comprises: a first relay driver for driving the first high-potential-side relay; a first upper-side monitoring circuit for monitoring a first supply voltage on the high-potential side of the first high-potential-side relay; and a first lower-side monitoring circuit for monitoring a voltage of the inter-relay connection line, i.e., a relay intermediate voltage, on the low-potential side of the first high-potential-side relay. The second relay control circuit includes: a second relay driver for driving the second high-potential-side relay; a second upper-side monitoring circuit for monitoring a second supply voltage on a high-potential side of the second high-potential-side relay; and a second lower-side monitoring circuit for monitoring the relay intermediate voltage on a low-potential side of the second high-potential-side relay; and The control unit controls on / off operations of the first high potential side relay and the second high potential side relay based on the first supply voltage, the second supply voltage, and the relay intermediate voltage.

2. The electronic control device according to claim 1, wherein: The inter-relay connection line is connected to a boost circuit via a switch and a current limiting circuit. The boost circuit can supply a voltage higher than that of the first external power supply and the second external power supply.

3. The electronic control device according to claim 2, wherein: When the boosted voltage from the boost circuit is applied to the inter-relay connection line with all relay elements of the first power supply relay unit and the second power supply relay unit disconnected, the control unit determines that an abnormality occurs if the relay intermediate voltage does not match the boosted voltage.

4. The electronic control device according to any one of claims 1 to 3, wherein: When it is determined based on the first supply voltage and the relay intermediate voltage that the first supply voltage is abnormal, the control unit turns off the first high potential side relay. The control unit turns off the second high-potential-side relay when it is determined that the second external power supply is abnormal based on the second supply voltage and the relay intermediate voltage.

5. The electronic control device according to claim 4, wherein: If the first high potential side relay or the second high potential side relay that is disconnected due to abnormal supply voltage is regarded as an abnormal system relay, When regenerative power is generated and the relay intermediate voltage is greater than a regeneration determination value, the control unit turns on the abnormal system relay.

6. A power supply system comprising: A plurality of redundant units, each unit being provided with an electronic control device according to any one of claims 1 to 5; the first external power source; and The second external power supply, The plurality of redundant units are connected in parallel to the first external power supply and the second external power supply.

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