Rotary body drive system

Abstract

The drive system (300) is set to a normal state in which the first switch (150) is on and the link switch (50) is off in a case where it is determined that the state of the first rotary body driven by the first motor (160) is not abnormal. Thereby, the first motor (160) is driven by the first inverter (120), and the second motor (260) is driven by the second inverter (220). On the other hand, in a case where it is determined that the state of the first rotary body is abnormal, the first switch (150) is set to off and the link switch (50) is set to on in a first countermeasure state. Therefore, the second motor (260) is driven by both the first inverter (120) and the second inverter (220).

Description

[0001] Citation of relevant applications

[0002] This application is based on Japanese Patent Application No. 2019-181703, filed on October 1, 2019, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a rotary body drive system for driving a rotating body. Background Technology

[0004] In a vehicle drive system, there exists a drive system (power system) with multiple electric motors that drive the tires and inverters that drive the electric motors. Moreover, as a document illustrating such technology, there is the following patent document 1.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-35243 Summary of the Invention

[0008] With a vehicle drive system like the one described above, even if one drive system fails, the other drive systems can compensate for its malfunction. Therefore, it is possible to prevent the vehicle from becoming immobile.

[0009] However, in such a vehicle drive system, if one of the drive tires gets stuck in mud or ice, reducing its traction, similar to a conventional vehicle drive system, only the torque from the drive tires other than that one can be transmitted to the ground. Therefore, it becomes difficult to extricate the vehicle from the mud or ice.

[0010] On the other hand, if you want to ensure sufficient driving performance to get out of mud or ice and snow even with only the torque of the drive tires other than the reduced traction, a high-output inverter is required.

[0011] Furthermore, similar problems can occur in rotating body drive systems other than vehicle drive systems. Specifically, for example, in drone drive systems, if one or more of the drone's multiple propellers fail due to damage, a soft landing is required while maintaining flight using only the output of the remaining propellers. In this case, a high-output inverter is needed to ensure flight performance is maintained as much as possible using only the remaining propellers.

[0012] This disclosure is made in view of the above circumstances, and its main purpose is to ensure that the output of other rotating components is sufficiently large in the event of a specified rotating component malfunction, without the need for a high-output inverter.

[0013] The rotating body drive system disclosed herein includes a first motor for driving a defined first rotating body, a second motor for driving a second rotating body different from the first rotating body, a first inverter for driving the first motor, and a second inverter for driving the second motor.

[0014] The aforementioned rotating body drive system further includes a first switch, a connection switch, a judgment unit, and a control unit. When the first switch is closed, it connects the first inverter and the first motor in a energizing manner; when it is open, it disconnects the connection. When the connection switch is closed, it connects the first inverter and the second motor in a energizing manner; when it is open, it disconnects the connection. The judgment unit determines whether the state of the first rotating body is abnormal. The control unit controls the first switch and the connection switch.

[0015] When the determination unit determines that the state of the first rotating body is normal, the control unit sets the rotating body drive system to a normal state where the first switch is on and the connection switch is off. Thus, the first motor is driven by the first inverter, and the second motor is driven by the second inverter.

[0016] On the other hand, when the determination unit determines that the state of the first rotating body is abnormal, the aforementioned rotating body drive system is set to a first response state by the control unit, where the first switch is open and the connection switch is closed. Thus, the second motor is driven by both the first inverter and the second inverter.

[0017] According to this disclosure, when the determination unit determines that the state of the first rotating body is abnormal, the control unit sets the control to the aforementioned first response state, thereby driving the second motor by both the first inverter and the second inverter. Therefore, compared to the case where the second motor is driven solely by the second inverter, the torque of the second rotating body can be increased. Thus, without needing to provide a high-output second inverter, the output of the second rotating body can be ensured to be sufficiently large when the first rotating body is abnormal. Attached Figure Description

[0018] The above-mentioned objects, other objects, features, and advantages of this disclosure will become clearer with reference to the accompanying drawings and the following detailed description. The accompanying drawings are described below.

[0019] Figure 1 This is a schematic diagram illustrating the rotating body drive system of the first embodiment.

[0020] Figure 2 This is a circuit diagram representing a rotating body drive system.

[0021] Figure 3 This is a circuit diagram representing the normal state of a rotating body drive system.

[0022] Figure 4 This is a circuit diagram representing the first response state of the rotating body drive system.

[0023] Figure 5 This is a circuit diagram representing the second response state of the rotating body drive system.

[0024] Figure 6 This is a flowchart representing connection control.

[0025] Figure 7 It is Figure 4 , Figure 5 Simplified circuit diagram. Detailed Implementation

[0026] [First Implementation Method]

[0027] Next, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments, and appropriate modifications can be made to implement them without departing from the spirit of the disclosure.

[0028] Figure 1 This is a schematic diagram illustrating the vehicle drive system 300 according to this embodiment. The vehicle drive system 300 is installed in the vehicle 400 and includes a host ECU 10, a battery 20, a first drive system 100, a second drive system 200, and a connection switch 50.

[0029] The first drive system 100 includes a first tire 190, a first electric motor 160, a first inverter 120, a first control unit 110, and a first switch 150. In this embodiment, the first tire 190 is the left front wheel and rotates together with the first rotation shaft 180.

[0030] The first motor 160 drives the first rotating shaft 180 to rotate via a reducer (not shown), thereby driving the first tire 190 to rotate. The first inverter 120 converts the DC power supplied from the battery 20 into AC power and supplies power to the first motor 160, thereby driving the first motor 160. The first control unit 110 controls the driving of the first tire 190 by the first motor 160 by controlling the first inverter 120.

[0031] In detail, the first drive system 100 inputs first motor information i1 obtained based on the drive of the first motor 160 to the first control unit 110. This first motor information i1 includes, for example, information related to the rotation angle of the rotor relative to the stator of the first motor 160, and information related to the currents flowing through the U-phase coil 164, V-phase coil 165, and W-phase coil 166 of the stator of the first motor 160. The first control unit 110 uses this first motor information i1 to control the first inverter 120, thereby controlling the drive of the first tire 190.

[0032] The second drive system 200 includes a second tire 290, a second electric motor 260, a second inverter 220, a second control unit 210, and a second switch 250. The second tire 290 is the right front wheel and rotates together with the second rotating shaft 280.

[0033] The more specific description of the second drive system 200 is the same as the description of the first drive system 100 described above, except that "first" is replaced with "second", "left" is replaced with "right", "U phase" is replaced with "X phase", "V phase" is replaced with "Y phase", "W phase" is replaced with "Z phase", and the symbols are replaced with the corresponding symbols.

[0034] Figure 2 This is a circuit diagram representing the vehicle drive system 300. First, the first drive system 100 will be described. The first motor 160 has a U-phase coil 164, a V-phase coil 165, and a W-phase coil 166, one end of which is connected to each other at the neutral point.

[0035] The first inverter 120 has a first upper wiring 122, three upper arms (124-126), three connecting lines (134-136), three lower arms (144-146), and a first lower wiring 148.

[0036] One end of the first upper wiring 122 is connected to the positive terminal of the battery 20. One end of the first lower wiring 148 is connected to the negative terminal of the battery 20.

[0037] The three connecting lines (134-136) include U-phase line 134, V-phase line 135, and W-phase line 136. One end of U-phase line 134 is connected to the end of U-phase coil 164 opposite to the neutral point. One end of V-phase line 135 is connected to the end of V-phase coil 165 opposite to the neutral point. One end of W-phase line 136 is connected to the end of W-phase coil 166 opposite to the neutral point.

[0038] The three upper arms (124-126) include a U-phase upper arm 124, a V-phase upper arm 125, and a W-phase upper arm 126. One end of the U-phase upper arm 124 is connected to the first upper wiring 122, and the other end is connected to the U-phase line 134. Furthermore, a U-phase upper switch Ua is provided at the midpoint of its length. One end of the V-phase upper arm 125 is connected to the first upper wiring 122, and the other end is connected to the V-phase line 135. Furthermore, a V-phase upper switch Va is provided at the midpoint of its length. One end of the W-phase upper arm 126 is connected to the first upper wiring 122, and the other end is connected to the W-phase line 136. Furthermore, a W-phase upper switch Wa is provided at the midpoint of its length.

[0039] The three lower arms (144-146) include a U-phase lower arm 144, a V-phase lower arm 145, and a W-phase lower arm 146. One end of the U-phase lower arm 144 is connected to the first lower wiring 148, and the other end is connected to the U-phase line 134. A U-phase lower switch Ub is provided at the midpoint of its length. One end of the V-phase lower arm 145 is connected to the first lower wiring 148, and the other end is connected to the V-phase line 135. A V-phase lower switch Vb is provided at the midpoint of its length. One end of the W-phase lower arm 146 is connected to the first lower wiring 148, and the other end is connected to the W-phase line 136. A W-phase lower switch Wb is provided at the midpoint of its length.

[0040] Furthermore, a first switch 150 is provided on the three connecting lines (134-136). Specifically, the first switch 150 has a U-phase switch 154, a V-phase switch 155, and a W-phase switch 156. The U-phase switch 154 is disposed between the upper arm (124) and the lower arm (144) of the U-phase line 134 and the U-phase coil 164. The V-phase switch 155 is disposed between the upper arm (125) and the lower arm (145) of the V-phase line 135 and the V-phase coil 165. The W-phase switch 156 is disposed between the upper arm (126) and the lower arm (146) of the W-phase line 136 and the W-phase coil 166.

[0041] Hereinafter, when "first switch 150" is referred to as "on", it means that all three switches (154-156) constituting the first switch 150 are "on", and when "first switch 150" is referred to as "off", it means that all three switches (154-156) are "off". When the first switch 150 is on, it connects the first inverter 120 and the first motor 160 in a way that allows power to be supplied, and when it is off, it disconnects the connection.

[0042] The first control unit 110 controls the first inverter 120 by controlling the connection and disconnection of the three upper switches (Ua, Va, Wa) and the three lower switches (Ub, Vb, Wb).

[0043] Next, the second drive system 200 will be described. The second motor 260 has an X-phase coil 264, a Y-phase coil 265, and a Z-phase coil 266. The second inverter 220 has a second upper wiring 222, three upper arms (224-226), three connecting lines (234-236), three lower arms (244-246), and a second lower wiring 248.

[0044] The three upper arms (224-226) include an X-phase upper arm 224, a Y-phase upper arm 225, and a Z-phase upper arm 226. An X-phase upper switch Xa is installed on the X-phase upper arm 224, a Y-phase upper switch Ya is installed on the Y-phase upper arm 225, and a Z-phase upper switch Za is installed on the Z-phase upper arm 226.

[0045] The three lower arms (244-246) include the X-phase lower arm 244, the Y-phase lower arm 245, and the Z-phase lower arm 246. An X-phase lower switch Xb is installed on the X-phase lower arm 244, a Y-phase lower switch Yb is installed on the Y-phase lower arm 245, and a Z-phase lower switch Zb is installed on the Z-phase lower arm 246.

[0046] The three phase wirings (234-236) include X-phase line 234, Y-phase line 235, and Z-phase line 236. The second switch 250 includes X-phase switch 254, Y-phase switch 255, and Z-phase switch 256.

[0047] The more specific description of the second drive system 200 is the same as the description of the first drive system 100 described above, except that "first" is replaced with "second", "U phase" is replaced with "X phase", "V phase" is replaced with "Y phase", "W phase" is replaced with "Z phase", and the symbols are replaced with the corresponding symbols.

[0048] Next, the connection switch 50 will be described. The connection switch 50 includes a UX connection switch 54, a VY connection switch 55, and a WZ connection switch 56. Specifically, the portion of the U-phase line 134 closer to the battery 20 side (opposite to the first motor 160 side) than the U-phase switch 154 is connected to the portion of the X-phase line 234 closer to the battery 20 side than the X-phase switch 254 via a UX connection line 34. A UX connection switch 54 is provided on this UX connection line 34.

[0049] Furthermore, the portion of the V-phase line 135 closer to the battery 20 than the V-phase switch 155 is connected to the portion of the Y-phase line 235 closer to the battery 20 than the Y-phase switch 255 via a VY connection line 35. A VY connection switch 55 is provided on this VY connection line 35. Additionally, the portion of the W-phase line 136 closer to the battery 20 than the W-phase switch 156 is connected to the portion of the Z-phase line 236 closer to the battery 20 than the Z-phase switch 256 via a WZ connection line 36. A WZ connection switch 56 is provided on this WZ connection line 36.

[0050] Hereinafter, "connecting switch 50" being "on" means that all three switches (54-56) constituting the connecting switch 50 are "on," and "connecting switch 50" being "off" means that all three switches (54-56) are "off." When the connecting switch 50 is on, the first inverter 120 and the second motor 260 are connected in a way that allows them to be energized, while the second switch 250 is on. The second inverter 220 and the first motor 160 are also connected in a way that allows them to be energized, while the first switch 150 is on. Conversely, when the connecting switch 50 is off, the first inverter 120 and the second motor 260 are de-energized, and the second inverter 220 and the first motor 160 are also de-energized.

[0051] Refer again Figure 1 The upper-level ECU 10 includes a judgment unit 14 and a control unit 15. The judgment unit 14 determines whether the traction of the first tire 190 and the second tire 290 is abnormal. Specifically, for example, if the rotational speed of the first tire 190 or the second tire 290 is higher than the rotational speed of the other tires, it can be determined that the traction is abnormal.

[0052] Furthermore, for example, the vehicle 400 may have a first tire pressure monitoring system (TPMS) that detects the tire pressure of the first tire 190 and a second tire pressure monitoring system (TPMS) that detects the tire pressure of the second tire 290. Then, the determination unit 14 can determine that there is an abnormal traction when the tire pressure detected by the aforementioned tire pressure monitoring system is low. This is because when the tire pressure is low, the tire may lift up, and the traction is more likely to decrease.

[0053] Hereinafter, the situation where the determination unit 14 determines that the traction of either the first tire 190 or the second tire 290 is not abnormal will be referred to as "normal situation". Furthermore, the situation where the determination unit 14 determines that only the traction of the first tire 190 is abnormal will be referred to as "first abnormal situation", and the situation where only the traction of the second tire 290 is abnormal will be referred to as "second abnormal situation". Additionally, the situation where the determination unit 14 determines that the traction of both the first tire 190 and the second tire 290 is abnormal will be referred to as "both abnormal situation".

[0054] In the event of a first malfunction, the second drive system 200 inputs the second motor information i2 not only to the second control unit 210, but also to the first control unit 110. Conversely, in the event of a second malfunction, the first drive system 100 inputs the first motor information i1 not only to the first control unit 110, but also to the second control unit 210.

[0055] Under normal conditions, the control unit 15 is configured in a normal state s0 where the first switch 150 is on, the second switch 250 is on, and the connecting switch 50 is off. On the other hand, in the event of a first abnormality, it is configured in a first response state s1 where the first switch 150 is off, the second switch 250 is on, and the connecting switch 50 is on. Furthermore, in the event of a second abnormality, it is configured in a second response state s2 where the first switch 150 is on, the second switch 250 is off, and the connecting switch 50 is on.

[0056] Figure 3 This is a circuit diagram representing the normal state s0 of the vehicle drive system 300. In this diagram, the U-phase lower switch Ub, V-phase upper switch Va, and W-phase lower switch Wb are closed, and the X-phase lower switch Xb, Y-phase upper switch Ya, and Z-phase lower switch Zb are also closed at specified moments. However, this represents a predetermined instant. Each upper switch (Ua, Va, Wa, Xa, Ya, Za) and each lower switch (Ub, Vb, Wb, Xb, Yb, Yb, Zb) is repeatedly switched on and off at predetermined times, thereby changing the direction of the current flowing to each motor (160, 260). The above situation... Figure 4 and Figure 5 The same applies to China.

[0057] In Figure 3 In the normal state s0 shown, the first inverter 120 drives the first motor 160 by supplying power to the first motor 160, and the second inverter 220 drives the second motor 260 by supplying power to the second motor 260.

[0058] In this normal state s0, the first motor 160 is driven with an output below a predetermined first upper limit output determined by the performance (limit output) of the first inverter 120. Then, the second motor 260 is driven with an output below a predetermined second upper limit output determined by the performance (limit output) of the second inverter 220. Furthermore, in this embodiment, the first upper limit output and the second upper limit output are the same.

[0059] Figure 4 This is a circuit diagram representing the first response state s1 of the vehicle drive system 300. In this first response state s1, since the first switch 150 is open, the first inverter 120 does not supply power to the first motor 160. On the other hand, since the second switch 250 and the connecting switch 50 are closed, the second inverter 220 and the first inverter 120 supply power to the second motor 260, and the second motor 260 is driven by both inverters 120 and 220.

[0060] In detail, as described above, in the first response state s1, the second drive system 200 not only inputs the second motor information i2 to the second control unit 210, but also inputs the second motor information i2 to the first control unit 110. The first control unit 110 uses the second motor information i2 to control the switches (Ua, Va, Wa, Ub, Vb, Wb) of the first inverter 120, thereby controlling the drive of the second motor 260 by the first inverter 120.

[0061] In this first response state s1, the second motor 260 is driven with an output greater than the aforementioned second upper limit output through the cooperation of the inverters (120, 220). The period during which the second motor 260 is driven with an output greater than the second upper limit output is within a predetermined second limiting time. This second limiting time is determined based on the time until a predetermined performance degradation occurs in the second motor 260 due to driving the second motor 260 with an output greater than the second upper limit output.

[0062] Specifically, the performance degradation specified is, for example, demagnetization of the rotor magnets caused by overheating of the second motor 260, or short circuits in the specified circuit. The second limiting time can be a variable determined based on the magnitude of the current flowing through the second motor 260 and the temperature of the second motor 260, or it can be a constant. If it is a variable, the second limiting time can be determined by mapping or by a function.

[0063] In the first response state s1, if the period during which the second tire 290 is driven with an output greater than the second upper limit exceeds the second limit time, it can return to the normal state s0, or it can maintain the first response state s1 and suppress the output of both inverters 120 and 220.

[0064] Figure 5 This is a circuit diagram representing the second response state s2 of the vehicle drive system 300. In this second response state s2, since the second switch 250 is open, the second inverter 220 does not supply power to the second motor 260. On the other hand, since the first switch 150 and the connecting switch 50 are closed, the first inverter 120 and the second inverter 220 supply power to the first motor 160, and the first motor 160 is driven by both inverters 120 and 220.

[0065] The more detailed description of the second response state s2 is the same as the description of the first response state s1 described above, except that each of the terms "first" and "second" is replaced with the other, and the symbols are replaced with the corresponding symbols.

[0066] Figure 6 This is a flowchart illustrating the connection control performed by the host ECU 10. The initial state is the normal state s0. Starting from this state, firstly, the determination unit 14 detects information related to the traction of the first tire 190 and the second tire 290 (S611). Next, it determines whether the traction of the first tire 190 is abnormal (S612).

[0067] In S612, if the traction of the first tire 190 is determined to be abnormal (S612: Yes), it is determined whether the traction of the second tire 290 is abnormal (S613). If the traction of the second tire 290 is determined to be abnormal (S613: Yes), it means that both tires are abnormal, therefore, the normal state s0 is maintained and the connection control is terminated.

[0068] On the other hand, in S613, if it is determined that the traction of the second tire 290 is not abnormal (S613: No), it means that only the traction of the first tire 190 is abnormal, therefore, the drive of the first motor 160 by the first inverter 120 is stopped (S614). Then, by setting the first switch 150 to open and the connection switch 50 to close (S615), the system switches to the first response state s1. Then, by starting the drive of the second motor 260 by the first inverter 120 (S616), the second motor 260 is driven by both inverters 120 and 220. In this state, the connection control ends.

[0069] On the other hand, in S612, if it is determined that the traction of the first tire 190 is not abnormal (S612: No), it is also determined whether the traction of the second tire 290 is abnormal (S623). If it is determined that the traction of the second tire 290 is not abnormal (S623: No), it means that the traction of both tires is normal. Therefore, the normal state s0 is maintained and the connection control is terminated.

[0070] On the other hand, in S623, if the traction of the second tire 290 is determined to be abnormal (S623: Yes), it means that only the traction of the second tire 290 is abnormal, therefore, the drive of the second motor 260 by the second inverter 220 is stopped (S624). Then, by setting the second switch 250 to open and the connection switch 50 to close (S625), the system switches to the second response state s2. Then, by starting the drive of the first motor 160 by the second inverter 220 (S626), the first motor 160 is driven by both inverters 120 and 220. In this state, the connection control ends.

[0071] Furthermore, after the connection control is terminated, control is performed as follows: When switching to the first response state s1 via the connection control, the system returns to the normal state s0, provided that the traction of the first tire 190 returns to normal. Similarly, when switching to the second response state s2 via the connection control, the system returns to the normal state s0, provided that the traction of the second tire 290 returns to normal.

[0072] Furthermore, in the first response state s1, if the period during which the second tire 290 is driven with an output greater than the second upper limit exceeds the second limit time, the system either returns to the normal state s0, or maintains the first response state s1 and suppresses the outputs of both inverters 120 and 220. Similarly, in the second response state s2, if the period during which the first tire 190 is driven with an output greater than the first upper limit exceeds the first limit time, the system either returns to the normal state s0, or maintains the second response state s2 and suppresses the outputs of both inverters 120 and 220.

[0073] According to this embodiment, the following effects can be obtained. When the traction of the first tire 190 is abnormal (a first abnormality), by driving the second motor 260 through both inverters (120, 220), the torque of the second tire 290 can be increased. (Refer to...) Figure 7 The details are explained below. In addition, the maximum value of the current that can flow through each upper switch (Ua, Va, Wa, Xa, Ya, Za) and each lower switch (Ub, Vb, Wb, Xb, Yb, Zb) will be set as "Imax".

[0074] If Figure 3 The circuit shown at a specified instant in the normal state s0 is simplified by omitting the circuit where no current flows, and becomes... Figure 7 The circuit diagram shown in (a) is as follows. Here, the positive terminal of battery 20 and the second motor 260 are connected via an upper switch (Ya). On the other hand, the negative terminal of battery 20 and the second motor 260 are connected via two lower switches (Xb, Zb) that exist in parallel. Therefore, the maximum current that can flow through the second motor 260 is the maximum value (Imax) of the current that can flow through the upper switch (Ya).

[0075] On the other hand, if Figure 4 The circuit shown at the specified instant of the first response state s1 is simplified by omitting the circuits through which no current flows, and thus becomes... Figure 7 The circuit diagram is shown in (b). Here, the positive terminal of battery 20 and the second motor 260 are connected via two upper switches (Va, Ya) connected in parallel. On the other hand, the negative terminal of battery 20 and the second motor 260 are connected via four lower switches (Ub, Wb, Xb, Zb) connected in parallel. Therefore, the maximum current that can flow through the second motor 260 is the maximum value of the total current that can flow through the two upper switches (Va, Ya) (2 × Imax).

[0076] As described above, the maximum current that can flow through the second motor 260 in the normal state s0 is Imax, and the maximum current that can flow through the second motor 260 in the first response state s1 is 2×Imax. Therefore, in the first response state s1, the second motor 260 can output approximately twice the maximum output (second upper limit output) in the normal state s0.

[0077] Therefore, in the event of a first anomaly such as the first tire 190 getting stuck in mud or snow, the torque of the second tire 290 can be sufficiently increased by setting it to the first response state s1. Thus, without the need for a high-output second inverter 220, the vehicle 400 can easily extricate itself from the mud or snow.

[0078] Similarly, in the event of a second abnormality where the second tire 290 becomes stuck in mud or snow, the torque of the first tire 190 can be sufficiently increased by setting the second response state s2. Therefore, without the need for a high-output first inverter 120, the vehicle 400 can easily extricate itself from the mud or snow.

[0079] Specifically, in this embodiment, the first tire 190 is the left wheel, and the second tire 290 is the right wheel. Therefore, in the event of a first abnormality where the first tire 190, as the left wheel, becomes stuck in mud or the like and its traction decreases, a first response state s1 is established. By increasing the torque of the second tire 290, as the right wheel, the vehicle 400 can easily detach from the mud or the like. Conversely, in the event of a second abnormality where the second tire 290, as the right wheel, becomes stuck in mud or the like and its traction decreases, a second response state s2 is established. By increasing the torque of the first tire 190, as the left wheel, the vehicle 400 can easily detach from the mud or the like.

[0080] Furthermore, in the first response state s1, the second drive system 200 inputs the second motor information i2 to the first control unit 110. Therefore, by using the second motor information i2, the first control unit 110 can control the drive of the second motor 260 by the first inverter 120 without any problems. Similarly, in the second response state s2, the first drive system 100 inputs the first motor information i1 to the second control unit 210. Therefore, by using the first motor information i1, the second control unit 210 can control the drive of the first motor 160 by the second inverter 220 without any problems.

[0081] Furthermore, when switching from the normal state s0 to the first response state s1, after stopping the drive of the first motor 160 by the first inverter 120 in the normal state s0, the first switch 150 is set to open and the connection switch 50 is set to close, thereby switching to the first response state s1. Therefore, the first switch 150 is set to open after no current flows through it. Therefore, compared to the case where the first switch 150 is set to open when current flows through it, insulation failure between the two terminals of the first switch 150 is less likely to occur. Therefore, the withstand voltage requirement of the first switch 150 can be suppressed to a lower level.

[0082] Similarly, when switching from the normal state s0 to the second response state s2, after stopping the drive of the second motor 260 by the second inverter 220 in the normal state s0, the second switch 250 is set to open and the connection switch 50 is set to close, thereby switching to the second response state s2. Therefore, similar to the case of the first switch 150 described above, the voltage withstand requirement of the second switch 250 can be suppressed to a lower level.

[0083] Furthermore, in the first response state s1, the second motor 260 is driven with an output greater than the aforementioned second upper limit output for a predetermined second limited time. This second limited time is determined based on the time until a predetermined performance degradation occurs in the second motor 260 due to driving the second motor 260 with an output greater than the second upper limit output. Therefore, it is possible to avoid such performance degradation in the second motor 260.

[0084] Similarly, in the second response state s2, the first motor 160 is driven with an output greater than the aforementioned first upper limit output for a predetermined first limited time. This first limited time is determined based on the time until a predetermined performance degradation occurs in the first motor 160 due to driving the first motor 160 with an output greater than the first upper limit output. Therefore, it is possible to avoid such performance degradation in the first motor 160.

[0085] [Other Implementation Methods]

[0086] The above embodiments can be implemented in a modified manner. For example, the first drive system 100 may drive the left and right front wheels instead of the left front wheel, and the second drive system 200 may drive the left and right rear wheels instead of the right front wheel. That is, the first tire 190 may be the left and right front wheels, and the second tire 290 may be the left and right rear wheels. In this case, for example, if the front wheel 190 gets stuck in mud or the like, by concentrating the torque on the second tire 290, the wheel can easily get out of the mud or the like.

[0087] Alternatively, for example, the second switch 250 can be omitted, and the system can switch from the normal state s0 to the first response state s1 only in the event of a first abnormality, while maintaining the normal state s0 without switching to the second response state s2 in the event of a second abnormality. In this case, for example, it is preferable to designate the tire on the side more likely to get stuck in mud or snow, such as the tire on the shoulder of the left or right tires or the rear tire of the front or rear tires, as the first tire 190.

[0088] Additionally, for example, in each circuit diagram ( Figures 2-5 , Figure 7 In the diagram, the upper switches (Ua, Va, Wa, Xa, Ya, Za) and the lower switches (Ub, Vb, Wb, Xb, Yb, Zb) are the usual symbols for transistors, but they can also be MOSFETs, IGBTs, etc.

[0089] Alternatively, for example, the aforementioned vehicle drive system 300 can also be used as a drone drive system to drive the drone's propellers. Specifically, for example, if the drone has four propellers—left front, right front, left rear, and right rear—the first motor 160 can drive the left front and right rear propellers (one diagonal propeller), and the second motor 260 can drive the right front and left rear propellers (the other diagonal propeller). In this case, for example, if one diagonal propeller is damaged or malfunctions, the output can be concentrated on the other diagonal propeller, and a soft landing can be achieved through the output of the other diagonal propeller.

[0090] Although this disclosure has been described based on embodiments, it should be understood that this disclosure is not limited to the above embodiments and structures. This disclosure also includes various modifications and equivalent variations. In addition, various combinations and methods, and further including other combinations and methods of only a single element or more or less, also fall within the scope and concept of this disclosure.

Claims

1. A rotating body drive system, the rotating body drive system comprising a first motor for driving a predetermined first rotating body, a second motor for driving a second rotating body different from the first rotating body, a first inverter for driving the first motor, and a second inverter for driving the second motor. The rotating body drive system has: The first switch connects the first inverter and the first motor in a energizing manner when it is turned on, and disconnects the connection when it is turned off. A connection switch that connects the first inverter and the second motor in a energized manner when it is turned on, and disconnects the connection when it is turned off. The determination unit determines whether the state of the first rotating body is abnormal; as well as The control unit controls the first switch and the connecting switch. If the determination unit determines that the state of the first rotating body is normal, the control unit sets the system to a normal state where the first switch is on and the connection switch is off, thereby driving the first motor through the first inverter and the second motor through the second inverter. If the determination unit determines that the state of the first rotating body is abnormal, the control unit sets the first switch to be open and the connection switch to be on as a first response state, thereby driving the second motor through the first inverter and the second inverter.

2. The rotating body driving system as described in claim 1, characterized in that, The first rotating body is one of the left and right tires of the vehicle, and the second rotating body is the other tire of the vehicle. As a criterion for determining whether the state is abnormal, the determination unit determines whether the traction is abnormal.

3. The rotary body drive system as described in claim 1 or 2, characterized in that, A system comprising the first motor, the first inverter, and a predetermined first control unit controlling the first inverter is designated as a first drive system, and a system comprising the second motor, the second inverter, and a predetermined second control unit controlling the second inverter is designated as a second drive system. In the first response state, the second drive system inputs the specified information obtained based on the drive of the second motor to the first control unit, and the first control unit uses the specified information to control the drive of the second motor by the first inverter.

4. The rotating body drive system as described in claim 1 or 2, characterized in that, When switching from the normal state to the first response state, after stopping the drive of the first motor by the first inverter in the normal state, the first switch is set to open, thereby switching to the first response state.

5. The rotating body drive system as described in claim 1 or 2, characterized in that, In the normal state, the second motor is driven by the second inverter with an output below a predetermined upper limit. In the first response state, through the cooperation of the first and second inverters, the second motor is driven with an output greater than the upper limit for a predetermined time period. The time limit is determined based on the time until a specified performance degradation occurs in the second motor due to driving the second motor with an output greater than the upper limit output.

6. A rotating body drive system, the rotating body drive system comprising a first motor for driving a predetermined first rotating body, a second motor for driving a second rotating body different from the first rotating body, a first inverter for driving the first motor, and a second inverter for driving the second motor. The rotating body drive system has: The first switch connects the first inverter and the first motor in a energizing manner when it is turned on, and disconnects the connection when it is turned off. The second switch connects the second inverter and the second motor in a energizing manner when it is turned on, and disconnects the connection when it is turned off. A connection switch, when switched to ON, connects the first inverter and the second motor in a energized manner when the second switch is ON, and connects the second inverter and the first motor in a energized manner when the first switch is ON; when switched to OFF, it prevents the first inverter and the second motor from being energized, and prevents the second inverter and the first motor from being energized. The judgment unit determines whether the states of the first rotating body and the second rotating body are abnormal. as well as The control unit controls the first switch, the second switch, and the connecting switch. If the determination unit determines that there is no abnormality in the traction of either the first rotating body or the second rotating body, the control unit sets the system to a normal state where the first switch is on, the second switch is on, and the connection switch is off. This allows the first motor to be driven by the first inverter, and the second motor to be driven by the second inverter. If the determination unit determines that the state of the first rotating body is abnormal, the control unit sets the first switch to open, the second switch to open, and the connection switch to open in a first response state, thereby driving the second motor through both the first inverter and the second inverter. If the determination unit determines that the state of the second rotating body is abnormal, the control unit sets the first switch to be on, the second switch to be off, and the connection switch to be on as a second response state, thereby driving the first motor through the first inverter and the second inverter.

7. The rotating body driving system as described in claim 6, characterized in that, The first rotating body is one of the left and right tires of the vehicle, and the second rotating body is the other tire of the vehicle. As a criterion for determining whether the state is abnormal, the determination unit determines whether the traction is abnormal.

8. The rotating body drive system as described in claim 6 or 7, characterized in that, A system comprising the first motor, the first inverter, and a predetermined first control unit controlling the first inverter is designated as a first drive system, and a system comprising the second motor, the second inverter, and a predetermined second control unit controlling the second inverter is designated as a second drive system. In the first response state, the second drive system inputs the specified information obtained based on the drive of the second motor to the first control unit, and the first control unit uses the specified information to control the drive of the second motor by the first inverter.

9. The rotating body drive system as described in claim 6 or 7, characterized in that, When switching from the normal state to the first response state, after stopping the drive of the first motor by the first inverter in the normal state, the first switch is set to open, thereby switching to the first response state.

10. The rotary body drive system as described in claim 6 or 7, characterized in that, In the normal state, the second motor is driven by the second inverter with an output below a predetermined upper limit. In the first response state, through the cooperation of the first and second inverters, the second motor is driven with an output greater than the upper limit for a predetermined time period. The time limit is determined based on the time until a specified performance degradation occurs in the second motor due to driving the second motor with an output greater than the upper limit output.

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