Power System

Abstract

To provide a power supply system capable of preventing the occurrence of an unexpected situation between a control unit for a device and a control unit for an auxiliary power supply.SOLUTION: A power supply system S includes control units 70, 80, an auxiliary power supply 121, and an auxiliary power supply control unit 128. Each of the control units 70, 80 is operated by using the power supplied from a main power supply 100 so as to control the operation of a steering device exhibiting a desired function. The auxiliary power supply 121 is provided separately from the main power supply 100 and functions to assist the supply of power to each of the control units 70, 80 according to a supplying state of the power performed by the main power supply 100. The auxiliary power supply control unit 128 is operated to control a supplying state of the power of the auxiliary power supply 121 to each of the control units 70, 80 so as to assist the supply of power. The steering-side control unit 70 of the control units 70, 80 is especially configured to output a stop permission FLG2 as information indicating, to the auxiliary power supply control unit 128, the stop of the operation when the steering-side control unit stops its operation.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a power supply system. [Background technology]

[0002] A control unit for a device that performs a desired function, for example, an electric power steering device (hereinafter referred to as EPS) for a vehicle, performs assist control using power supplied from a main power supply mounted on the vehicle. Some control units for devices are configured to supplement the supply of power from the main power supply with the function of an auxiliary power supply provided separately from the main power supply.

[0003] Patent Document 1 discloses a control unit for EPS, and as an example of a mode of assisting the supply of power from a main power source to the control unit for EPS, discloses providing a control unit for an auxiliary power source that controls the operation of an auxiliary power source that operates to boost and assist the power. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-140883 A Summary of the Invention [Problem to be solved by the invention]

[0005] As for the power from the main power source, the operating state of the control unit for the device that uses the power supplied from the main power source is set in association with the state of power supply from the main power source while switching between supply and stop. Similarly, the operating state of the control unit for the auxiliary power source that controls the operation of the auxiliary power source that supplements the power supply from the main power source is set in association with the state of power supply from the main power source. However, for the control unit for the device and the control unit for the auxiliary power source, ingenuity is required so that they do not continue to operate in a situation where they should be stopped, or stop operating in a situation where they should not be stopped, or so that unexpected situations do not occur between the control units in relation to the operating states of the other control units. [Means for solving the problem]

[0006] The power supply system for solving the above problem includes a control unit for the device that operates using power supplied from a main power supply to control the operation of the device to perform a desired function, an auxiliary power supply that is provided separately from the main power supply and functions to assist the supply of power to the control unit for the device depending on the state of the power supply from the main power supply, and a control unit for the auxiliary power supply that operates to control the state of the power supply from the auxiliary power supply to the control unit for the device to perform the assistance. The part , For this device Information on the control unit For the auxiliary power supply The control unit is configured to output the for equipment When the control unit stops the operation, For auxiliary power supply The control unit is configured to output information indicating that the operation is to be stopped to the control unit.

[0007] According to the above configuration, the control Department When the operation stops, For auxiliary power supply The control unit of for equipment In this case, the information indicating that the operation is to be stopped can be obtained from the control unit of the For auxiliary power supply When the control unit of the for equipmentIt is possible to determine whether to stop or continue to operate, taking into consideration whether the control unit for the device stops operating. As a result, it is possible to determine rules for the control unit for the device and the control unit for the auxiliary power supply, so that they do not continue to operate in a situation where they should be stopped, or stop operating in a situation where they should not be stopped, in relation to the operating states of the other control units. Therefore, it is possible to prevent an unexpected situation from occurring between the control unit for the device and the control unit for the auxiliary power supply.

[0008] In the above power supply system, the main power supply When a start switch for turning on and off the function of the device mounted on the device is turned on, the control unit for the device is electric power of supply do Status and As it becomes , When the start switch is turned off, the supply of power to the control unit for the device is stopped. and for equipment The control unit Turning the start switch on and off In determining whether to stop the operation based on the above, when determining to stop the operation For auxiliary power supply It is preferable that the control unit is configured to output information indicating that the operation is to be stopped to the control unit.

[0009] According to the above configuration, the state of the power supply from the main power source, i.e. Turning the start switch on and off In consideration of the above, a rule can be established so that the control unit for the device and the control unit for the auxiliary power supply stop operating in a situation where they should be stopped. In this case, Turning the start switch on and off It is effective for the controller for the device to perform appropriate control in response to the

[0010] In the above power supply system ,before Note For equipment The control unit A start switch that turns on and off the functions of the device installed in the device In order to determine the above, an external control unit provided at the mounting location of the device is provided separately from the control unit for the device and the control unit for the auxiliary power supply. Turning the start switch on and off The device is configured to allow input of information indicating For equipment When the control unit stops the operation, Turning the start switch off When determining For equipment The control unit transmits information indicating that the operation is to be stopped to the Auxiliary power supply The control unit is configured to output the Auxiliary power supply The control unit For equipmentThe relevant information input from the control unit For equipment It is preferable that the control unit is configured to use the information indicating that the operation is to be stopped to determine whether or not to stop the operation.

[0011] According to the above configuration, the external control unit Turning the start switch on and off You can enter information that indicates For equipment It is possible to determine rules so that the control unit is the main body and the control unit for the device and the control unit for the auxiliary power supply stop operating in a situation where they should be stopped. In this case, it is effective in more suitably preventing an unexpected situation from occurring between the control unit for the device and the control unit for the auxiliary power supply.

[0012] In the power supply system, the control unit for the device and the control unit for the auxiliary power supply are A start switch that turns on and off the functions of the device installed in the device It is preferable that the main power supply is configured to be able to use the power supply voltage as information indicative of the state of the power supply in order to determine the above.

[0013] According to the above configuration, the control unit for the device and the control unit for the auxiliary power supply are controlled by, for example, an external control unit. Turning the start switch on and off Even if you can't use the information to show Turning the start switch on and off It is possible to determine the following: Turning the start switch on and off When judging ,main power supply Power supply voltage In addition, from the external control unit Input start switch on / off It is also possible to use multiple pieces of information from different sources, such as information showing Turning the start switch on and off This can improve the accuracy of determining the following.

[0014] In the above power supply system, the auxiliary power supply is supplied by the main power supply. Voltage The auxiliary power supply is provided between the main power supply and the control unit for the device, and supplies power to the control unit for the device by backing up the supply of power to the control unit for the device in place of the main power supply under the condition that the voltage of the main power supply or the auxiliary power supply is lowered. expensive The other power supply a selection circuit configured to select Etc.It is preferable that

[0015] In the above configuration, the voltage supplied by the main power supply or the auxiliary power supply is selected by the function of the selection circuit. expensive The other power supply In this case, for example, the main power supply is Voltage Considering that the auxiliary power supply backs up the drop in the power supply, it is conceivable that the auxiliary power supply could back up the supply of power to the control unit for the device in place of the main power supply even when the main power supply stops supplying power. This can be dealt with by establishing rules so that the control unit for the auxiliary power supply can stop operating when the control unit for the device stops operating. In this way, Voltage When the auxiliary power supply backs up a drop in the power supply voltage, it is possible to prevent an unexpected situation from occurring between the control unit for the device and the control unit for the auxiliary power supply.

[0016] The selection circuit can be embodied as having a first diode provided in a first power supply path which is a path when power from the main power source is supplied to a control unit for the device, and a second diode provided in a second power supply path which is connected to the control unit side for the device of the first diode provided in the first power supply path and is a path when power from the auxiliary power source is supplied to the control unit for the device.

[0017] In the above power supply system, it is preferable that the device is a steering device mounted on a vehicle and functions to operate at least one of a steering wheel and steered wheels provided on the vehicle, and that a control unit for the device is configured to control the operation of the steering device.

[0018] As described above, in a steering device employing the above-mentioned power supply system, it is possible to prevent an unexpected situation from occurring between the control unit for the device and the control unit for the auxiliary power supply, which is effective in improving the marketability of the steering device. Effect of the Invention

[0019] According to the power supply system of the present invention, it is possible to prevent an unexpected situation from occurring between the control unit for the device and the control unit for the auxiliary power supply. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a diagram showing a schematic configuration of a steering device according to the first embodiment. [Diagram 2] FIG. 2 is a block diagram of a power supply system according to the first embodiment. [Diagram 3] FIG. 2 is a block diagram of a power supply system for the steering unit in the first embodiment. [Figure 4] (a) is the on / off state of the start switch, (b) is the detection of each power supply voltage, (c) and (d) are the output of the vehicle stop flag, (e) is the output of the stop permission flag, (f) is the operation of the auxiliary power control unit, and (g) is a diagram showing each state of power supply to each control unit. [Diagram 5] FIG. 11 is a block diagram of a power supply system according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] First Embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a power supply system will now be described with reference to the drawings. The power supply system of this embodiment is applied so as to constitute a part of a steering device 2 mounted on a vehicle.

[0022] As shown in Fig. 1, the steering device 2 is a steer-by-wire type steering device. The steering device 2 includes a steering control device 1 that controls the operation of the steering device 2. The steering device 2 includes a steering section 4 that is steered by a driver via a steering wheel 3, and a steering section 6 that steers steered wheels 5 in response to steering input to the steering section 4 by the driver. The steering device 2 of this embodiment has a structure in which the power transmission paths between the steering section 4 and the steering section 6 are mechanically separated at all times.

[0023] The steering section 4 includes a steering shaft 11 to which the steering wheel 3 is fixed, and a steering actuator 12 that applies a steering reaction force, which is a force resisting steering by the driver, to the steering wheel 3 via the steering shaft 11. The steering actuator 12 includes a steering-side motor 13 that serves as a drive source, and a steering-side reduction mechanism 14 that reduces the rotation of the steering-side motor 13 and transmits it to the steering shaft 11. For example, a three-phase brushless motor is used as the steering-side motor 13 in this embodiment.

[0024] The steered portion 6 includes a first pinion shaft 21 and a rack shaft 22 as a steered shaft connected to the first pinion shaft 21. The first pinion shaft 21 and the rack shaft 22 are arranged at a predetermined cross angle. A first rack-and-pinion mechanism 23 is formed by meshing pinion teeth 21a formed on the first pinion shaft 21 with first rack teeth 22a formed on the rack shaft 22. Tie rods 24 are connected to both ends of the rack shaft 22. The ends of the tie rods 24 are connected to knuckles (not shown) to which the left and right steered wheels 5 are assembled, respectively.

[0025] The steering unit 6 includes a steering actuator 31 that applies a steering force to the rack shaft 22 to steer the steered wheels 5. The steering actuator 31 applies a steering force to the rack shaft 22 via a second pinion shaft 32. The steering actuator 31 includes a steering-side motor 33 that serves as a drive source, and a steering-side reduction mechanism 34 that reduces the rotation of the steering-side motor 33 and transmits it to the second pinion shaft 32. The second pinion shaft 32 and the rack shaft 22 are disposed at a predetermined cross angle. A second rack and pinion mechanism 35 is configured by meshing second pinion teeth 32a formed on the second pinion shaft 32 with second rack teeth 22b formed on the rack shaft 22.

[0026] In the steering device 2 configured in this manner, the second pinion shaft 32 is rotationally driven by the steering actuator 31 in response to the steering operation by the driver, and this rotation is converted into axial movement of the rack shaft 22 by the second rack and pinion mechanism 35, thereby changing the steering angle of the steered wheels 5. At this time, a force acting in the opposite direction to the steering direction by the driver is applied to the steering wheel 3 from the steering actuator 12 as a steering reaction force that resists the steering by the driver.

[0027] The reason for providing the first pinion shaft 21 is to support the rack shaft 22 together with the first pinion shaft 21 inside a housing (not shown). That is, the rack shaft 22 is supported movably along its axial direction and is pressed toward the first pinion shaft 21 and the second pinion shaft 32 by a support mechanism (not shown) provided in the steering device 2. In this way, the rack shaft 22 is supported inside the housing. However, another support mechanism for supporting the rack shaft 22 in the housing may be provided without using the first pinion shaft 21.

[0028] As shown in Fig. 1, the steering control device 1 is connected to a steering side motor 13 and a turning side motor 33. The steering control device 1 controls the operation of the steering side motor 13 and the turning side motor 33. In other words, the steering control device 1 controls the operation of the motors 13, 33, so that the steering device 2 operates to perform the desired function as a steer-by-wire type steering device.

[0029] A torque sensor 41 that detects the steering torque Th applied to the steering shaft 11 is connected to the steering control device 1. The torque sensor 41 is provided on the steering shaft 11 closer to the steering wheel 3 than the connecting portion with the steering side reduction gear mechanism 14. The torque sensor 41 detects the steering torque Th based on the twist of a torsion bar provided midway on the steering shaft 11.

[0030] A steering side rotation angle sensor 42 and a turning side rotation angle sensor 43 are connected to the steering control device 1. The steering side rotation angle sensor 42 detects the steering side rotation angle θa of the steering side motor 13 as a relative angle within a range of 360 degrees. The turning side rotation angle sensor 43 detects the turning side rotation angle θb of the turning side motor 33 as a relative angle within a range of 360 degrees.

[0031] A vehicle speed sensor 44 is connected to the steering control device 1. The vehicle speed sensor 44 detects a vehicle speed value V that is set as information indicating the traveling speed of the vehicle. An external control device 60 is connected to the steering control device 1 via an in-vehicle network 50 such as a CAN. The external control device 60 is provided in the vehicle separately from the steering control device 1, and controls the operation of a device that performs a desired function different from the function performed by the steering device 2. The steering control device 1 receives information from the external control device 60 via the in-vehicle network 50.

[0032] The electrical configuration of the steering control device 1 will be described. As shown in Fig. 2, the steering control device 1 has a steering side control unit 70 that controls power supply to the steering side motor 13, and a turning side control unit 80 that controls power supply to the turning side motor 33. The steering side control unit 70 and the turning side control unit 80 transmit and receive information to each other via a local network 90 such as serial communication. The steering side control unit 70 is provided as a part of the configuration of the steering unit 4. In addition, the turning side control unit 80 is provided as a part of the configuration of the turning unit 6.

[0033] The steering-side control unit 70 calculates a reaction force control amount, which is a target of the steering reaction force of the steering wheel 3 to be generated through the steering-side motor 13, based on the detection results of the various sensors described above. Then, the steering-side control unit 70 controls the supply of power to the steering-side motor 13, based on the reaction force control amount. Also, the turning-side control unit 80 calculates a steering control amount, which is a target of the steering force to be generated through the turning-side motor 33, based on the detection results of the various sensors described above. Then, the turning-side control unit 80 controls the supply of power to the turning-side motor 33, based on the turning control amount.

[0034] The steering side control unit 70 includes a central processing unit (CPU) and a memory (not shown), and the CPU executes a program stored in the memory at each predetermined calculation cycle. This executes various processes. The steering side control unit 70 is configured to have two systems, a main control unit 70a and a sub-control unit 70b, as a control system that combines a CPU and a memory to execute various processes. In this embodiment, the steering side control unit 70 operates in a master-slave control system in which the main control unit 70a is the master control unit and the sub-control unit 70b is the slave control unit. This is the same for the turning side control unit 80. In other words, the turning side control unit 80 has two systems, a main control unit 80a and a sub-control unit 80b, as a control unit that combines a CPU and a memory to execute various processes, and these are configured to operate in a master-slave control system.

[0035] The control units 70a, 70b of the steering-side control unit 70 and the control units 80a, 80b of the turning-side control unit 80 are configured to be able to communicate with each other via a local network 90. ​​The control units 70a, 70b of the steering-side control unit 70 and the control units 80a, 80b of the turning-side control unit 80 are also configured to be able to communicate with an external control unit 60a of the external control device 60 via an in-vehicle network 50.

[0036] A main power supply 100 is connected to the steering device 2. The main power supply 100 is a secondary battery mounted on the vehicle, and serves as a power source for supplying power to operate the motors 13, 33, as well as a power source for supplying power to operate the steering side control unit 70 and the steered side control unit 80.

[0037] Between the steering device 2 and the main power supply 100, a vehicle start switch 110 such as an ignition switch is provided. The start switch 110 is provided in the middle of the power supply line L2 that branches off from a connection point P0 of the power supply line L1, one of two power supply lines L1 and L2 that connect the steering device 2 and the main power supply 100. The start switch 110 is operated when starting various functions so that the vehicle can be operated by operating a driving source for running the vehicle, such as an engine. The conduction of the power supply line L2 is turned on and off through the operation of the start switch 110. In this embodiment, the operating state of the steering device 2 that can perform the desired function as a steer-by-wire type steering device is associated with the operating state of the vehicle. Note that the conduction of the power supply line L1 is basically always on, but the conduction of the power supply line L1 is indirectly turned on and off as a function of the steering device 2 depending on the operating state of the steering device 2. In other words, the operating state of the steering device 2 is associated with the state of the power supply from the main power supply 100, ie, the on / off state of the electrical continuity of each of the power supply lines L1, L2.

[0038] In the steering device 2, the power supply lines L1, L2, i.e., the main power supply 100, are connected to the steering side control unit 70, particularly the main control unit 70a, via the auxiliary power supply device 120. Also, the power supply lines L1, L2, i.e., the main power supply 100 are directly connected to the steering side control unit 70, particularly the sub-control unit 70b, without passing through the auxiliary power supply device 120. This is also true for the turning side control unit 80, and the power supply lines L1, L2, i.e., the main power supply 100 are connected to the steering side control unit 80, particularly the main control unit 80a, via the auxiliary power supply device 120. Also, the power supply lines L1, L2, i.e., the main power supply 100 are directly connected to the steering side control unit 80, particularly the sub-control unit 80b, without passing through the auxiliary power supply device 120. That is, in this embodiment, a single auxiliary power supply device 120 is shared between the steering side control unit 70 and the turning side control unit 80.

[0039] The auxiliary power supply 120 does not have a function of receiving information from the external control device 60 via the in-vehicle network 50. In other words, the auxiliary power supply 120 is physically separated from the in-vehicle network 50 and is configured not to receive information from the external control device 60 via the in-vehicle network 50. On the other hand, the auxiliary power supply 120 is configured to be able to communicate with the main control unit 70a of the steering side control unit 70 via a dedicated signal line 140. In contrast, the auxiliary power supply 120 is not configured to be able to communicate with the main control unit 80a of the turning side control unit 80 via a dedicated signal line. This is because the position at which the auxiliary power supply 120 of this embodiment is provided is set relatively close to the steering unit 4 between the steering unit 4 and the turning unit 6 in the steering device 2.

[0040] In this embodiment, the auxiliary power supply 120 is prepared as an auxiliary power supply for the steering side control unit 70 and the turning side control unit 80, i.e., the steering device 2. The auxiliary power supply 120, the steering side control unit 70, and the turning side control unit 80 configure a power supply system S. The power supply system S is applied as a power supply system for the steering unit 4 and the turning unit 6, i.e., the steering device 2.

[0041] The configuration of the power supply system S will be described in detail below. Here, the configuration related to the steering unit 4 will be mainly described, and with regard to the configuration related to the steered unit 6, only the configuration different from the configuration related to the steering unit 4 will be described.

[0042] As shown in Fig. 3, power from the main power supply 100 is supplied to a power circuit 71a of the main control unit 70a via a power supply line L11 branching off from a connection point P11 of a power supply line L1. The power circuit 71a is a circuit that handles larger power and includes, for example, an inverter that converts DC power from the main power supply 100 to AC power. Power from the main power supply 100 is supplied to a control circuit 72a of the main control unit 70a via a power supply line L21 branching off from a connection point P12 of a power supply line L2. The control circuit 72a is a circuit for controlling the steering-side motor 13 and includes, for example, a CPU and a memory.

[0043] Moreover, the power of the main power supply 100 is supplied to a power circuit 71b of the sub-controller 70b via a power line L12 branching off from a connection point P11 of the power line L1. The power circuit 71b has the same configuration as the power circuit 71a. The power of the main power supply 100 is supplied to a control circuit 72b of the sub-controller 70b via a power line L22 branching off from a connection point P12 of the power line L2. The control circuit 72b has the same configuration as the control circuit 72a.

[0044] Also, the turning side control section 80 has a configuration corresponding to the steering side control section 70. That is, the turning side control section 80 has a configuration corresponding to the power circuit 71a and the control circuit 72a for the main control section 80a. The turning side control section 80 has a configuration corresponding to the power circuit 71b and the control circuit 72b for the sub-control section 80b. That is, as shown in FIG. 3, the turning side control section 80 has a power circuit 81a and a control circuit 82a for the main control section 80a. Similarly, the turning side control section 80 has a power circuit 81a and a control circuit 82b for the sub-control section 80b. Note that the main control section 80a is different in that the control circuit 82a is not configured to be able to output information to the auxiliary power supply control section 128 (described later) of the auxiliary power supply device 120 via the signal line 140.

[0045] Next, the configuration of the auxiliary power supply 120 will be described in detail. As shown in FIG. 3, the auxiliary power supply device 120 includes an auxiliary power supply 121, an electric circuit 122, switches 123, 124, and 125, diodes 126 and 127, and an auxiliary power supply control unit 128.

[0046] The auxiliary power supply 121 is a capacitor such as a lithium ion capacitor that functions similarly to a secondary battery. The auxiliary power supply 121 serves as a power source of power supplied to operate the steering-side motor 13, and also serves as a power source of power supplied to operate the steering-side control unit 70. The same is true for the steering unit 6, and the auxiliary power supply 121 serves as a power source of power supplied to the steering-side motor 33, and also serves as a power source of power supplied to the steering-side control unit 80.

[0047] As expressed by the following equation (A), the voltage V2 of the auxiliary power supply 121 is set to a value higher than the voltage V0 required to properly operate each of the motors 13, 33 or each of the control units 70, 80, and lower than the voltage V1 of the main power supply 100.

[0048] V1>V2>V0 …(A) Inside the auxiliary power supply device 120, the auxiliary power supply 121 is connected to a connection point P11 of the power supply line L11 via a power supply line L111 branching off from a connection point P13 of the power supply line L11. Also, inside the auxiliary power supply device 120, the auxiliary power supply 121 is connected to a connection point P11 of the power supply line L11 via a power supply line L112 branching off from a connection point P14 of the power supply line L11. However, the connection point P14 is located downstream of the connection point P13, that is, on the steering side control unit 70 (steered side control unit 80) side. The auxiliary power supply 121 functions to assist the supply of power to the steering side control unit 70 (steered side control unit 80) depending on the state of the power supply by the main power supply 100. In this embodiment, the auxiliary power supply 121 backs up the supply of power to the steering side control unit 70 (steered side control unit 80) in place of the main power supply 100 on the condition that the power supplied by the main power supply 100 is reduced.

[0049] The electric circuit 122 switches the connection state to the power line L11 so as to charge and discharge the auxiliary power supply 121. In addition, the electric circuit 122 switches the connection state to the power line L11 so as to disconnect the auxiliary power supply 121 so as to prevent the auxiliary power supply 121 from discharging electric charge.

[0050] The switch 123 is provided midway through the power line L11 inside the auxiliary power device 120. The switch 123 is located upstream of the connection point P13, closer to the main power supply 100. The switch 123 opens and closes the power line L11.

[0051] The switch 124 is provided midway along the power line L111 inside the auxiliary power device 120. The switch 124 opens and closes the power line L111. The switch 125 is provided midway along the power line L112 inside the auxiliary power device 120. The switch 125 opens and closes the power line L112.

[0052] A connection point P15 is set on the power line L112. Inside the auxiliary power device 120, the connection point P15 of the power line L112 and a connection point P16 of the power line L21 are connected by a power line L113.

[0053] The diode 126 is provided in the middle of the power supply line L113. The cathode of the diode 126 is connected to a connection point P16 of the power supply line L21. The anode of the diode 126 is connected to a connection point P15 of the power supply line L113.

[0054] The diode 127 is provided in the middle of the power supply line L21. The cathode of the diode 127 is connected to a connection point P16 of the power supply line L21. The anode of the diode 127 is connected to a connection point P12 of the power supply line L21.

[0055] The diodes 126, 127 allow the flow of power from the anode to the cathode, while restricting the flow of power from the cathode to the anode. The diodes 126, 127 configure an OR circuit that supplies the power supplied by the main power supply 100 or the auxiliary power supply 121, whichever has a higher voltage, to the control circuit 72a. The OR circuit configured by the diodes 126, 127 is a so-called wired OR. The OR circuit configured by the diodes 126, 127 corresponds to a selection circuit that selects the power supplied by the main power supply 100 or the auxiliary power supply 121, whichever has a higher voltage, to supply power to the steering side control unit 70 (steered side control unit 80).

[0056] The auxiliary power control unit 128 includes a central processing unit (CPU) and memory (not shown), and the CPU executes a program stored in the memory at each predetermined calculation cycle, thereby executing various types of processing.

[0057] Specifically, the auxiliary power control unit 128 controls switching of the connection state of the electric circuit 122, and also controls opening and closing of the switches 123, 124, and 125. The auxiliary power control unit 128 monitors the voltage of the main power supply 100. As expressed by the following formula (B), the auxiliary power control unit 128 determines that the power supply voltage Vb of the main power supply 100 has dropped when the power supply voltage Vb of the main power supply 100 is lower than a threshold voltage Vth1. The threshold voltage Vth1 is a criterion for determining a voltage drop of the main power supply 100, and is set based on a voltage V0 required for appropriately operating each of the motors 13, 33 or each of the control units 70, 80. In this embodiment, the threshold voltage Vth1 is set to the same value as the voltage V0.

[0058] Vb <Vth1 …(B) When no voltage drop of the main power supply 100 is detected, the auxiliary power supply control unit 128 maintains the switches 123, 124 in the on closed state and maintains the switch 125 in the off open state. Furthermore, when a voltage drop of the main power supply 100 is detected, the auxiliary power supply control unit 128 switches the switches 123, 124 from the on closed state to the off open state. Thereafter, the auxiliary power supply control unit 128 switches the switch 125 from the off open state to the on closed state.

[0059] Specifically, when the power supply voltage Vb of the main power supply 100 does not drop, the switches 123 and 124 are maintained in an on-closed state, and the switch 125 is maintained in an off-open state.

[0060] For example, in the steering section 4, power from the main power supply 100 is supplied to a power circuit 71a in the steering-side control section 70 via a power supply line L11. Also, power from the main power supply 100 is charged to the auxiliary power supply 121 via a power supply line L111.

[0061] When the power supply voltage Vb of the main power supply 100 has not dropped, when the start switch 110 is turned on, the power of the main power supply 100 is supplied to the control circuit 72a in the steering-side control unit 70 via the power supply line L21. Incidentally, since the power supply voltage Vb of the main power supply 100 is set higher than the voltage V2 of the auxiliary power supply 121, the power of the auxiliary power supply 121 is basically not supplied to the steering-side control unit 70 via the power supply line L113 and a part of the power supply line L21. In addition, the diode 126 prevents the power of the main power supply 100 that has passed through the power supply line L21 from flowing into the auxiliary power supply 121 via the power supply line L113.

[0062] When the main power supply 100 fails and the power supply voltage Vb of the main power supply 100 falls below the voltage V2 of the auxiliary power supply 121, power from the auxiliary power supply 121 is immediately supplied to the control circuit 72a in the steering-side control unit 70 via the power supply line L113 and a part of the power supply line L21. This is because the voltage V2 of the auxiliary power supply 121 becomes higher than the voltage generated in the power supply line L2. Even if the power supply from the main power supply 100 to the steering-side control unit 70 is interrupted due to a failure of the main power supply 100, the power supply to the control circuit 72a is backed up by the auxiliary power supply 121.

[0063] When the power supply voltage Vb of the main power supply 100 further drops and falls below the threshold voltage Vth1, the switches 123 and 124 are switched from the on-closed state to the off-open state. After this, the switch 125 is switched from the off-open state to the on-closed state. As a result, the power of the auxiliary power supply 121 is supplied to the power circuit 71a in the steering-side control unit 70 via the power supply line L112 and a part of the power supply line L11. This is because the voltage V2 of the auxiliary power supply 121 becomes higher than the voltage generated in the power supply line L11 due to a failure of the main power supply 100. Therefore, even if the power supply from the main power supply 100 to the steering-side control unit 70 is interrupted due to a failure of the main power supply 100, the power supply to the power circuit 71a in the steering-side control unit 70 is backed up by the auxiliary power supply 121.

[0064] Incidentally, it is conceivable to provide a diode in place of the switch 125 in the power supply line L112. In this way, when the main power supply 100 fails, power from the auxiliary power supply 121 is instantly supplied to the power circuit 71a. However, a diode generates power loss. For this reason, from the viewpoint of suppressing consumption of the auxiliary power supply 121, a switch 125 is provided in place of a diode in the power supply line L112 for supplying power to the power circuit 71a that requires larger power.

[0065] It is also possible to provide a switch in place of the diode 126 in the power line L113. However, in this case, the following concerns arise. That is, after the main power supply 100 fails and the supply of power from the main power supply 100 is cut off, it takes a short time for the switch of the power line L113 to switch from off to on. Therefore, during the period until the switch of the power line L113 switches from off to on, the power supply to the control circuit 72a is momentarily cut off, and the control circuit 72a may be reset. In this regard, if the diode 126 is provided in the power line L113, when the main power supply 100 fails, the power of the auxiliary power supply 121 is instantly supplied to the control circuit 72a via the power line L113 and a part of the power line L21. Since the power supply to the control circuit 72a is not cut off, the control circuit 72a is not reset due to a drop in its power supply voltage.

[0066] In this embodiment, the steering side control unit 70 and the turning side control unit 80, i.e., the steering control device 1, correspond to a control unit for the device. The diode 127 corresponds to a first diode. The diode 126 corresponds to a second diode. The power supply line L21 corresponds to a first power supply path. The power supply line L113 corresponds to a second power supply path. The auxiliary power supply control unit 128 corresponds to a control unit for the auxiliary power supply.

[0067] In the steering-side control unit 70, the control circuit 72a has a function of detecting the voltage of the power supplied through the power line L21 as the power voltage Vig1 of the main power supply 100. The power voltage Vig1 is the power voltage at the connection point P16 of the power line L21. In addition, the control circuit 72b has a function of detecting the voltage of the power supplied through the power line L22 as the power voltage Vig2 of the main power supply 100. The power voltage Vig2 is the power voltage at the connection point P12 of the power line L21. Similarly, the control circuit 82a of the main control unit 80a of the turning-side control unit 80 having the same configuration as the steering-side control unit 70 has a function of detecting the voltage of the power supplied through the power line corresponding to the power line L21 as the power voltage Vig3 of the main power supply 100. In addition, the control circuit 82b of the sub-control unit 80b of the turning-side control unit 80 has a function of detecting the voltage of the power supplied through the power line corresponding to the power line L22 as the power voltage Vig4 of the main power supply 100. The power supply voltages Vig1 to Vig4 detected in this manner are configured to be shared by each control unit 70, 80 by being output to each control unit 70a, 70b of the steering side control unit 70 and each control unit 80a, 80b of the turning side control unit 80 via the local network 90.

[0068] For example, in the main control unit 70a, the control circuit 72a acquires the power supply voltages Vig2 and Vig4 input via the local network 90. In the main control unit 70a, the control circuit 72a acquires the vehicle stop FLG1 input via the in-vehicle network 50 and acquires the turning-side vehicle stop FLG1t input via the local network 90. ​​The vehicle stop FLG1 is information indicating the state of the vehicle operation that is generated by the external control unit 60a and output to the in-vehicle network 50. That is, the vehicle stop FLG1 is information indicating that the vehicle operation is stopped, that is, the start switch 110 is off and the supply of power from the main power source 100 is stopped. Note that the external control unit 60a is configured to generate the vehicle stop FLG1 as a result of determining the stop of the vehicle operation by, for example, detecting the on / off of the start switch 110 or detecting the vehicle speed value V of the vehicle speed sensor 44. The turning-side vehicle stop FLG1t is information generated based on the vehicle stop FLG1 acquired by the control circuit 82a of the main control unit 80a of the turning-side control unit 80 via the in-vehicle network 50, and is information acquired by the control circuit 72a from the control circuit 82a via the local network 90. That is, in the turning side control unit 80, the control circuit 82a, like the control circuit 72a, acquires the vehicle stop FLG1 input via the in-vehicle network 50. The vehicle stop FLG1 acquired in this way by the control circuit 82a is output as the turning side vehicle stop FLG1t to the main control unit 70a of the steering side control unit 70 via the local network 90.

[0069] Then, the control circuit 72a determines that the start switch 110 is off and the state of the power supply from the main power source 100 is a state in which the supply of power is stopped, on the condition that each of the power source voltages Vig2, Vig4 is smaller than the threshold voltage Vth2, the vehicle stop FLG1 has been acquired, and the steering-side vehicle stop FLG1t has been acquired. That is, the control circuit 72a confirms that the power source voltage Vig2 detected by the steering-side control unit 70 and the power source voltage Vig4 acquired from the steering-side control unit 80 are both smaller than the threshold voltage Vth2. The threshold voltage Vth2 is set based on the power source voltage Vig2 when the power supply from the main power source 100 is in a stopped state, which is an experimentally determined range value that can be used to determine that the power supply from the main power source 100 is in a stopped state, and the value of the power source voltage Vig4 that is assumed to show approximately the same value as the power source voltage Vig2.

[0070] In this embodiment, when it is determined that the start switch 110 is off and the power supply of the main power supply 100 is stopped, the conditions of the power supply voltages Vig2 and Vig4 are added, but the conditions of the power supply voltages Vig1 and Vig3 are not added. This is because, while the power supply voltages Vig2 and Vig4 are displaced so as to decrease toward the threshold voltage Vth2 when the start switch 110 is off, there is a possibility that the power supply voltages Vig1 and Vig3 do not decrease toward the threshold voltage Vth2 when the start switch 110 is off. The reason why the power supply voltages Vig1 and Vig3 do not decrease toward the threshold voltage Vth2 when the start switch 110 is off is because, even when the start switch 110 is off, the supply of power may be maintained through the functions of the auxiliary power supply 121 and the diodes 126 and 127 in the same way as when the start switch 110 is on.

[0071] Note that, when determining that the power supply from the main power supply 100 is stopped, the control circuit 72a may be configured to compare either one of the power supply voltages Vig2 and Vig4 with the threshold voltage Vth2, assuming that the power supply voltages Vig2 and Vig4 have substantially the same value. Note that, when determining that the power supply from the main power supply 100 is stopped, if it is detected that not only the power supply voltage Vig2 but also the power supply voltage Vig1 have both dropped, it can be inferred that some kind of abnormality has occurred with the power supply, such as the start switch 110 being off, for example, a break in the power lines L21 and L22. If some kind of abnormality has occurred with the power supply, other than the start switch 110 being off, the control circuit 72a can be configured to preferentially execute a fail-safe control for stopping the vehicle. Also, assuming that the power supply voltages Vig1 to Vig4 have substantially the same value when the main power supply 100 is supplying power, for example, the absolute value of the deviation between the power supply voltage Vig1 and the power supply voltage Vig2 is information indicating the amount of displacement by which the power supply voltage Vig2 is lowered when the start switch 110 is off. In this case, the determination that the power supply from the main power supply 100 is stopped may be made by comparing the absolute value of the deviation between the power supply voltages Vig1 and Vig2 with a threshold value, and using the result of the comparison as a condition. Also, the determination that the power supply from the main power supply 100 is stopped may be made by comparing the vehicle stop FLG1 with the steering-side vehicle stop FLG1t, and using as a condition whether these values ​​match.

[0072] Then, when the control circuit 72a judges that the power supply from the main power source 100 is stopped, it executes processing related to the stop to stop the operation of the steering side control unit 70. In this case, that is, when the operation of the steering side control unit 70 is stopped, the control circuit 72a executes processing required to stop the operation of the steering side control unit 70, and then generates a stop permission FLG2 as information indicating that the operation is stopped for the auxiliary power source control unit 128, and outputs it to the auxiliary power source control unit 128 via the signal line 140. Note that, after the output of the stop permission FLG2 by the control circuit 72a, the steering side control unit 70 may be in a state where it does not execute any processing, or may be in a state where it executes some processing as long as it is processing that is not affected even if the power supply from the main power source 100 and the auxiliary power source 121 is suddenly stopped. This is the same for the turning side control unit 80. In other words, the turning side control unit 80 judges that the power supply from the main power source 100 is stopped through the processing of the control circuit 82a based on each power source voltage Vig2, Vig4 and the vehicle stop FLG1. Then, when the control circuit 82a judges that the power supply of the main power source 100 is stopped, the turning side control unit 80 outputs the turning side vehicle stop FLG1t generated based on the vehicle stop FLG1 to the steering side control unit 70 via the local network 90 after executing the process related to the stop to stop the operation of the turning side control unit 80. In other words, the turning side vehicle stop FLG1t is information indicating that the turning side control unit 80 will stop the operation. The stop permission FLG2 generated in consideration of such a turning side vehicle stop FLG1t is also information indicating that the turning side control unit 80 will stop the operation. As described above, the turning side control unit 80 may be in a state where it does not execute any process after the output of the turning side vehicle stop FLG1t by the control circuit 82a, or may be in a state where it executes some process as long as it is a process that will not be affected even if the power supply of the main power source 100 and the auxiliary power source 121 is suddenly stopped.

[0073] After the control circuit 72a outputs the stop permission FLG2, the steering-side control unit 70 actually stops the function of backing up the supply of power from the main power supply 100 by the auxiliary power supply 121, thereby stopping the supply of power from the main power supply 100 and the auxiliary power supply 121. In other words, there is a slight time difference between the timing of outputting the stop permission FLG2 and the timing at which the supply of power from the main power supply 100 and the auxiliary power supply 121 to the steering-side control unit 70 is stopped. This slight time difference includes the time from when the stop permission FLG2 is output until it is input to the auxiliary power supply control unit 128, the time from when the stop permission FLG2 is input until the auxiliary power supply control unit 128 actually stops the operation, etc.

[0074] On the other hand, if the conditions that each power supply voltage Vig2, Vig4 is smaller than the threshold voltage Vth2, the vehicle stop FLG1 has been acquired, and the steering side vehicle stop FLG1t has been acquired are not met, the control circuit 72a does not determine that the supply of power from the main power supply 100 is stopped, and does not generate and output the stop permission FLG2.

[0075] The auxiliary power control unit 128 executes processing related to the stop to stop the operation of the steering-side control unit 70 on the condition that the stop permission FLG2 input via the signal line 140 is acquired. In this case, that is, when the operation of the steering-side control unit 70 is stopped, the auxiliary power control unit 128 controls to switch the connection state of the electric circuit 122 so that power from the auxiliary power source 121 is not supplied. In other words, the auxiliary power device 120 stops the supply of power to the steering-side control unit 70 by stopping the backup function of the auxiliary power source 121 to supply power to the main power source 100. In this case, the auxiliary power device 120 stops the backup function of the auxiliary power source 121 to supply power to the main power source 100, regardless of the amount of remaining charge in the auxiliary power source 121.

[0076] As a result, when the power supply from the main power source 100 is stopped, the power supply from the auxiliary power source 121 is avoided by switching the connection state of the electric circuit 122, and the power supply to the steering-side control unit 70 is stopped. In this case, when the power supply from the main power source 100 is stopped, the steering-side control unit 70 stops without continuing to operate. The same applies to the turning-side control unit 80. In other words, when the power supply from the main power source 100 is stopped, the power supply from the auxiliary power source 121 is avoided by switching the connection state of the electric circuit 122, and the power supply to the turning-side control unit 80 is stopped. In this case, when the power supply from the main power source 100 is stopped, the power supply from the main power source 100 is stopped, and the turning-side control unit 80 stops without continuing to operate.

[0077] The situation where the voltage drop of the main power supply 100 is detected includes a situation where the start switch 110 is off and a situation where the main power supply 100 fails while the start switch 110 is on, and the power supply from the main power supply 100 to the steering-side control unit 70 is interrupted. In particular, in a situation where the main power supply 100 fails, the power supply voltages Vig2 and Vig4 are smaller than the threshold voltage Vth2, but the vehicle stop FLG1, the turning-side vehicle stop FLG1t, and the stop permission FLG2 are not generated and output, respectively. In a situation where the main power supply 100 fails, the auxiliary power supply control unit 128 outputs information indicating that to the steering-side control unit 70 via the signal line 140. In this case, the steering-side control unit 70 executes control according to the situation where the main power supply 100 fails. In addition, information indicating the situation where the main power supply 100 fails is input to the steering-side control unit 80 from the steering-side control unit 70 via the local network 90. In this case, the steering side control unit 80 executes control according to the situation in which the main power supply 100 has failed.

[0078] The operation of this embodiment will now be described. According to this embodiment, when the steering side control unit 70 and the turning side control unit 80, i.e., the steering control device 1, stop operating, the auxiliary power supply control unit 128 can obtain the stop permission FLG2 as information indicating that the operation is to be stopped from the steering side control unit 70. In this case, when attempting to stop operating, the auxiliary power supply control unit 128 can determine whether to stop operating or to continue operating, taking into consideration whether each of the control units 70, 80 stops operating.

[0079] 4(a) shows the on / off state of the start switch 110, i.e., the state in which power is being supplied from the main power source 100, which changes over time t. When the start switch 110 is on, power from the main power source 100 is basically supplied to the steering device 2, i.e., the steering side control unit 70 and the steered side control unit 80, unless there is a failure in the main power source 100.

[0080] In this case, as shown in FIG. 4(b)-(g), for example, in the power supply system S, the detection of each power supply voltage Vig2, Vig4, the output of the vehicle stop FLG1, the output of the steered side vehicle stop FLG1t, the output of the stop permission FLG2, the operation of the auxiliary power supply control unit 128, and the supply of power to each control unit 70, 80 indicate the on state of the start switch 110. That is, each power supply voltage Vig2, Vig4 is detected as a value equal to or higher than the threshold voltage Vth2, which is a state indicated by "1" in the figure. The vehicle stop FLG1 is a state indicated by "0 (zero)" in the figure in which no output is given from the external control unit 60a. The steered side vehicle stop FLG1t is a state indicated by "0 (zero)" in the figure in which no output is given from the control circuit 82a of the steered side control unit 80. The stop permission FLG2 is a state indicated by "0 (zero)" in the figure in which no output is given from the control circuit 72a of the main control unit 70a. The auxiliary power supply control unit 128 is in an "on" state in the figure, operating so that if the power supplied by the main power supply 100 drops, the auxiliary power supply 121 can provide backup power. Power is supplied to the control units 70, 80 so that the control units 70, 80 can continue to operate using power supplied by the main power supply 100 or the auxiliary power supply 121, as shown by "on" in the figure.

[0081] Then, as shown in FIG. 4(a), when the start switch 110 is switched to the OFF state, the supply of power from the main power source 100 to the control units 70, 80 is stopped. In this case, as shown in Fig. 4(b) to (g), for example, in the power supply system S, the detection of each power supply voltage Vig2, Vig4, the output of the vehicle stop FLG1, the output of the turning side vehicle stop FLG1t, the output of the stop permission FLG2, the operation of the auxiliary power supply control unit 128, and the supply of power to each control unit 70, 80 indicate the off state of the start switch 110. That is, each power supply voltage Vig2, Vig4 transitions to a state indicated by "0 (zero)" in the figure, in which it is detected as a value smaller than the threshold voltage Vth2. The vehicle stop FLG1 transitions to a state indicated by "1" in the figure, in which it is output from the external control unit 60a. The turning side vehicle stop FLG1t transitions to a state indicated by "1" in the figure, in which it is output from the control circuit 82a of the turning side control unit 80.

[0082] Thereafter, as shown in FIG. 4(e), the stop permission FLG2 transitions to the state indicated by "1" in the figure, in which the vehicle stop FLG1 is acquired by the control circuit 72a of the main control unit 70a, and after the steering side vehicle stop FLG1t is acquired, it is output from the control circuit 72a.

[0083] Next, as shown in FIG. 4(f), the auxiliary power supply control unit 128 transitions to the state indicated by “OFF” in the figure so as to stop the backup function of the power supply of the main power supply 100 by the auxiliary power supply 121, on the condition that the stop permission FLG2 has been acquired.

[0084] Next, as shown in FIG. 4(g), the supply of power to each control unit 70, 80 is stopped through the cessation of operation of the auxiliary power control unit 128 so that each control unit 70, 80 does not continue to operate using power supplied by the main power supply 100 and the auxiliary power supply 121, which is the state shown as "off" in the figure.

[0085] In this way, for example, in relation to the operating state of the steering-side control unit 70, the auxiliary power supply control unit 128 can stop operating without continuing to operate in a situation where the steering-side control unit 70 stops operating, and can continue to operate without stopping in a situation where the steering-side control unit 70 continues operating. The same is true for the turning-side control unit 80, and in relation to the operating state of the turning-side control unit 80, the auxiliary power supply control unit 128 can stop operating without continuing to operate in a situation where the turning-side control unit 80 stops operating, and can continue to operate without stopping in a situation where the turning-side control unit 80 continues operating.

[0086] The effects of the first embodiment will be described. (1-1) For example, if the configuration of generating and outputting the stop permission FLG2 is not provided, even if the control units 70 and 80 try to stop the operation when the power supply from the main power supply 100 is stopped, the auxiliary power supply control unit 128 may not be able to recognize that the control units 70 and 80 are trying to stop the operation. If the auxiliary power supply control unit 128 tries to continue operating even when the main power supply 100 stops supplying power, the auxiliary power supply 121 will back up the supply of power to the control circuits 72a and 82a in place of the main power supply 100. In this case, the control units 70 and 80 will continue to be supplied with power from the auxiliary power supply 121, resulting in an unexpected situation in which the control units 70 and 80 continue to operate even though they are in a situation in which they should stop operating when the power supply from the main power supply 100 is stopped. This is particularly problematic when the device has a function of a diode OR in which the power supplied by the main power supply 100 or the auxiliary power supply 121, whichever has the higher voltage, is selected, as in this embodiment.

[0087] In contrast to this, in this embodiment, rules can be established for each of the control units 70, 80 and the auxiliary power control unit 128 so that they do not continue to operate when they should be stopped, or stop operating when they should not be stopped, in relation to the operating states of other control units. This makes it possible to prevent unexpected situations between each of the control units 70, 80 and the auxiliary power control unit 128.

[0088] (1-2) When each of the control units 70, 80 stops operating, the vehicle stop FLG1, which is information indicating the state of power supply from the main power source 100, i.e., the operating state of the vehicle, is taken into consideration, and rules are established so that each of the control units 70, 80 and the auxiliary power supply control unit 128 stops operating in a situation where they should be stopped. In this case, it is effective for each of the control units 70, 80 to implement appropriate control according to the operating state of the vehicle.

[0089] (1-3) According to this embodiment, the control units 70, 80 serving as first control units that can input the vehicle stop FLG1 from the external control unit 60a are the main control units, and rules are established so that the control units 70, 80 and the auxiliary power supply control unit 128 serving as the second control unit stop operating in a situation where they should be stopped. In this case, it is effective in more suitably preventing an unexpected situation from occurring between the control units 70, 80 and the auxiliary power supply control unit 128.

[0090] (1-4) When determining the operating state of the vehicle, the steering side control unit 70 uses a plurality of pieces of information from different information sources, such as the power supply voltages Vig2 and Vig4 as well as the vehicle stop FLG1 obtained from the external control unit 60a. In this case, the accuracy of determining the operating state of the vehicle can be improved.

[0091] (1-5) In the steering device 2 employing the power supply system S of this embodiment, it is possible to prevent unexpected situations from occurring between the control units 70, 80 and the auxiliary power supply control unit 128. In this case, it is effective in improving the marketability of the steering device 2.

[0092] (1-6) For example, when the steering side control unit 70, i.e., the steering control device 1, has a function of self-diagnosis, or so-called diagnosis, it generates and stores diagnosis information, which is information for identifying the type of abnormality detected as a result of the diagnosis at the time of future maintenance. The type of abnormality detected as a result of the diagnosis includes, for example, a communication abnormality in which communication between the steering side control unit 70 and the auxiliary power supply control unit 128 via the signal line 140 is not performed normally. A situation that should be detected as this communication abnormality is a situation in which the auxiliary power supply control unit 128 stops operating while the steering side control unit 70 continues to operate while communication is being performed between the steering side control unit 70 and the auxiliary power supply control unit 128 via the signal line 140.

[0093] In this case, as described in the above effect (1-1), if there is no configuration for generating and outputting the stop permission FLG2, the steering side control unit 70 and the auxiliary power control unit 128 will stop operating without understanding each other's situation when the supply of power from the main power supply 100 is stopped. Due to this, there is a possibility that a communication abnormality will be detected as a result of the diagnosis even if the situation is not one in which a communication abnormality should be detected. In this case, it will not be possible to correctly identify the abnormality during future maintenance, which will lead to a decrease in the work efficiency of maintenance work, etc.

[0094] In contrast to this, in this embodiment, when the steering-side control unit 70 generates and outputs the stop permission FLG2, even if a communication abnormality occurs between the steering-side control unit 70 and the auxiliary power supply control unit 128, a condition can be set so that this is not detected as a communication abnormality. Therefore, in a state where the supply of power from the main power supply 100 is stopped, it is possible to suppress occurrences of a communication abnormality being detected as a result of a diagnosis in a situation where a communication abnormality should be detected.

[0095] <Second embodiment> A second embodiment of the power supply system will now be described with reference to the drawings. Note that the same components as those in the first embodiment already described will be given the same reference numerals and the like, and duplicated descriptions thereof will be omitted.

[0096] In this embodiment, each control unit 70, 80 is individually provided with an auxiliary power supply 120 corresponding to it, and a single auxiliary power supply 120 is not shared between the control units 70, 80, which is different from the first embodiment described above.

[0097] Specifically, as shown in Fig. 5, a steering-side auxiliary power supply device 120S is provided as an auxiliary power supply device for the steering-side control unit 70. The steering-side auxiliary power supply device 120S and the steering-side control unit 70 constitute a power supply system SS. The power supply system SS is applied as a power supply system for the steering unit 4 in the steering device 2. Similarly, a turning-side auxiliary power supply device 120T is provided as an auxiliary power supply device for the turning-side control unit 80. The turning-side auxiliary power supply device 120T and the turning-side control unit 80 constitute a power supply system ST. The power supply system ST is applied as a power supply system for the steering unit 6 in the steering device 2.

[0098] The specific configuration of the steering-side control unit 70 is the same as that realized by replacing the auxiliary power supply 120S with the auxiliary power supply 120 of the first embodiment. For example, the power supply lines L1, L2, i.e., the main power supply 100, are connected to the main control unit 70a of the steering-side control unit 70 via the auxiliary power supply 120S. Moreover, the power supply lines L1, L2, i.e., the main power supply 100 are directly connected to the sub-control unit 70b of the steering-side control unit 70 without via the auxiliary power supply 120S. Moreover, the auxiliary power supply 120S is configured to be capable of communicating with the main control unit 70a of the steering-side control unit 70 via a dedicated signal line 140S.

[0099] Also, the specific configuration of the turning side control unit 80 is the same as the configuration realized by replacing the auxiliary power supply 120T with the auxiliary power supply 120 of the first embodiment and the turning side control unit 80 with the steering side control unit 70 of the first embodiment. For example, the main control unit 80a of the turning side control unit 80 is connected to each power supply line L1, L2, i.e., the main power supply 100, via the auxiliary power supply 120T. Also, the sub-control unit 70b of the turning side control unit 80 is directly connected to each power supply line L1, L2, i.e., the main power supply 100, without via the auxiliary power supply 120T. Also, the auxiliary power supply 120T is configured to be able to communicate with the main control unit 80a of the turning side control unit 80 via a dedicated signal line 140T.

[0100] In this case, for the steering-side control unit 70, the control circuit 72a determines that the start switch 110 is off and the supply of power from the main power source 100 is stopped, on the condition that both of the power source voltages Vig2, Vig4 are smaller than the threshold voltage Vth2 and the vehicle stop FLG1 has been acquired, and generates and outputs the stop permission FLG2. As a result, the auxiliary power supply device 120S stops the supply of power to the steering-side control unit 70 by stopping the backup function of the power supply from the main power source 100 by the auxiliary power source 121.

[0101] Furthermore, for the turning-side control unit 80, the control circuit 82a determines that the start switch 110 is off and the supply of power from the main power source 100 is stopped, on the condition that both of the power source voltages Vig2, Vig4 are smaller than the threshold voltage Vth2 and the vehicle stop FLG1 has been acquired, and generates and outputs the stop permission FLG2. As a result, the auxiliary power supply device 120T stops the supply of power to the turning-side control unit 80 by stopping the backup function of the supply of power from the main power source 100 by the auxiliary power source 121.

[0102] According to the second embodiment, the same functions and effects as those of the first embodiment are achieved. The above-described embodiments may be modified as follows. In addition, the following other embodiments may be combined with each other to the extent that there is no technical contradiction.

[0103] In the first embodiment, the diodes 126, 127 may be configured to configure an OR circuit inside the steering side control unit 70, i.e., the steering control device 1. Even in this case, the power selected from the main power supply 100 and the auxiliary power supply 121, whichever supplies the larger voltage, is supplied to the steering side control unit 70. This is the same for the auxiliary power supply units 120S, 120T of the second embodiment.

[0104] In the first embodiment, an electric double layer capacitor or a secondary battery may be used instead of the lithium ion capacitor for the auxiliary power supply 121. The same applies to the auxiliary power supplies of the auxiliary power supply devices 120S, 120T in the second embodiment.

[0105] In the first embodiment, the voltage V2 of the auxiliary power supply 121 may be set to a value similar to the voltage V1 of the main power supply 100, or may be set to a value higher than the voltage V1 of the main power supply 100. The same applies to the voltage V2 of the auxiliary power supplies of the auxiliary power supply devices 120S, 120T in the second embodiment.

[0106] In the first embodiment, the auxiliary power supply 120 may operate to boost the power supplied by the main power supply 100, in addition to backing up the power supply to the control units 70 and 80 in place of the main power supply 100. In this case, the auxiliary power supply 120 may eliminate a configuration equivalent to a selection circuit, such as an OR circuit formed by diodes 126 and 127. The same applies to the auxiliary power supplies 120S and 120T of the second embodiment.

[0107] In the first embodiment, the steering-side control unit 70 may use the power supply voltage Vb instead of the power supply voltages Vig2 and Vig4 to determine the on / off state of the start switch 110. This also applies to the control units 70 and 80 in the second embodiment.

[0108] In the first embodiment, each of the control units 70, 80 may be provided with a function of generating information corresponding to the vehicle stop FLG1 as a result of determining that the vehicle is stopped by, for example, detecting the on / off state of the start switch 110 or detecting the vehicle speed value V of the vehicle speed sensor 44. This also applies to the control units 70, 80 in the second embodiment.

[0109] In the first embodiment, when the start switch 110 is off and the state of the power supply from the main power source 100 is determined to be the state of the power supply being stopped, the steering-side control unit 70 may use at least one of the vehicle stop FLG1, the steered-side vehicle stop FLG1t, and each of the power source voltages Vig2, Vig4. This is the same for the control units 70, 80 in the second embodiment.

[0110] In the first embodiment, the steering side control unit 70 may not take the steered side vehicle stop FLG1t into consideration when generating the stop permission FLG2. For example, the steering side control unit 70 may output the acquired steered side vehicle stop FLG1t as is to the auxiliary power supply control unit 128. In this case, the auxiliary power supply control unit 128 may execute processing related to the stop to stop the operation of the steering side control unit 70 on the condition that both the stop permission FLG2 and the vehicle stop FLG1t have been acquired.

[0111] In the first embodiment, the steering side control unit 70 can also output the acquired vehicle stop FLG1 to the auxiliary power control unit 128 via the signal line 140. The vehicle stop FLG1 output in this way is shared between the steering side control unit 70 and the auxiliary power control unit 128. From the viewpoint of sharing the vehicle stop FLG1 in this way, the auxiliary power control unit 128 may be configured to acquire the vehicle stop FLG1 through the in-vehicle network 50 and output the acquired vehicle stop FLG1 to the steering side control unit 70 via the signal line 140. In this case, the steering side control unit 70 may be configured to output the acquired vehicle stop FLG1 to the turning side control unit 80 via the local network 90. ​​In other words, the auxiliary power control unit 128 may be connected so as to be able to communicate via the in-vehicle network 50. In this case, the auxiliary power control unit 128 may be added with a function for determining that the operation of the vehicle is stopped, that is, that the start switch 110 is off and the supply of power from the main power supply 100 is stopped. Also, the auxiliary power control unit 128 may generate information corresponding to the stop permission FLG2 indicating that the operation is to be stopped, and output it to the steering-side control unit 70 via the signal line 140. In this case, the steering-side control unit 70 may be configured to output information corresponding to the acquired stop permission FLG2 to the steering-side control unit 80 via the local network 90. ​​With this configuration, it is possible to determine rules so that the operation of each control unit 70, 80 and the auxiliary power control unit 128 is stopped in a situation where it should be stopped, mainly by the auxiliary power control unit 128. However, the auxiliary power control unit 128 may be configured to stop the operation after a predetermined time has elapsed after outputting the information corresponding to the stop permission FLG2, which is set as a range of time within which each control unit 70, 80 can execute the process of stopping the operation, or to input the stop permission FLG2 from each control unit 70, 80. This is also true for each control unit 70, 80 of the second embodiment and the auxiliary power control unit of each auxiliary power unit 120S, 120T.

[0112] In the first embodiment, the auxiliary power supply control unit 128 may be configured to be able to communicate with the main control unit 80a of the turning side control unit 80 via the signal line 140. That is, the main control unit 80a of the turning side control unit 80 may be configured to generate information corresponding to the stop permission FLG2 of the first embodiment and directly output the information to the auxiliary power supply control unit 128. In this case, the auxiliary power supply control unit 128 may not be configured to be able to communicate with the main control unit 70a of the steering side control unit 70 via the signal line 140. That is, the main control unit 70a of the steering side control unit 70 may be configured to generate information corresponding to the turning side vehicle stop FLG1t of the first embodiment and output the information to the main control unit 80a of the turning side control unit 80.

[0113] In the first embodiment, the processing function for determining that the power supply from the main power source 100 is stopped and for generating and outputting the stop permission FLG2 may be realized as a function of the steering control device 1, and may be changed as appropriate without being limited to being realized as a function of the steering side control unit 70, i.e., the control circuit 72a of the main control unit 70a. The above processing function may be provided as a function of both the main control unit 70a and the sub control unit 70b of the steering side control unit 70, for example, or as a function of only the sub control unit 70b. This is also true for the main control unit 80a and the sub control unit 80b of the turning side control unit 80. In this case, the above processing function may be provided as a function of both the main control unit 70a or the main control unit 70a and the sub control unit 70b of the steering side control unit 70, and may be provided as a function of both the main control unit 80a or the main control unit 80a and the sub control unit 80b of the turning side control unit 80. That is, for example, between the control units 70 and 80, a method may be adopted in which the above-mentioned processing functions include the determination and generation of the stop permission FLG2, and the results of each execution are shared and arbitrated through the local network 90. ​​Such a method may be realized between the control units 70a, 70b, 80a, and 80b. This is also true for the second embodiment, and each control unit 70 and 80 may have the functions of both the main control unit 70a and 80a and the sub-control unit 70b and 80b, or may have the functions of only the sub-control unit 70b and 80b.

[0114] In the first embodiment, each of the control units 70, 80 may have a function to detect only the necessary power supply voltages. That is, the steering-side control unit 70 may have a function to detect only the power supply voltage Vig2 by deleting the function to detect the power supply voltage Vig1. Also, the steered-side control unit 80 may have a function to detect only the power supply voltage Vig4 by deleting the function to detect the power supply voltage Vig3. This is the same for the second embodiment.

[0115] In the first embodiment, each of the main control units 70a, 80a may have a function of detecting each of the power supply voltages Vig2, Vig4. This also applies to the second embodiment.

[0116] In the first embodiment, each of the control units 70, 80 may be configured with only one system of the main control unit 70a, 80a by deleting each of the sub-control units 70b, 80b. In this case, each of the main control units 70a, 80a of only one system may have a function to detect the necessary power supply voltage. This is also true for the second embodiment.

[0117] In the first embodiment, the steering-side control unit 70 may be provided with a function of cutting off the power line L21 by itself at the timing of outputting the stop permission FLG2. The same applies to the turning-side control unit 80, which may be provided with a function of cutting off the power line L21 by itself at the timing of outputting the turning-side vehicle stop FLG1t. In this case, in each of the control units 70, 80, a switch or the like that can be switched by the control circuit 72a may be provided between the connection point P16 of the power line L21 and the control circuit 72a. The same applies to the control units 70, 80 of the second embodiment.

[0118] In the steering control device 1, the steering side control unit 70 may be configured as a single control unit having a function that combines the function of operating the steering side motor 13 and the function of the turning side control unit 80 that operates the turning side motor 33.

[0119] The steered-side motor 33 may be connected to the rack shaft 22 via a belt-type reducer using a ball screw mechanism, or may be connected coaxially to the rack shaft 22. Each of the control units 70, 80 and the steering control device 1 including these may be configured by a processing circuit including: 1) one or more processors that operate according to a computer program (software), 2) one or more dedicated hardware circuits such as an application specific integrated circuit (ASIC) that executes at least some of the various processes, or 3) a combination thereof. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to execute the processes. The memory, i.e., a non-transitory computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer. The same applies to the auxiliary power control unit 128 and the auxiliary power unit 120 including the same.

[0120] The steering device 2 has a linkless structure in which the steering unit 4 and the steered unit 6 are mechanically separated at all times, but is not limited to this, and may have a structure in which the steering unit 4 and the steered unit 6 can be mechanically separated by a clutch 25, as shown by the two-dot chain line in Fig. 1. In addition, the steering device 2 is not limited to a steer-by-wire type steering device, and may be an electric power steering device in which the torque of a motor is applied to the steering shaft 11 or the rack shaft 22.

[0121] The above-described embodiments are not limited to being realized as functions of the steering control device 1, and may be realized as, for example, a control device for an airbag device, a control device for a brake device, or a control device for a motor that serves as a driving source for driving an unmanned guided vehicle or an electric vehicle. Note that the above-described embodiments may also be realized as a control device for a device other than a vehicle. [Explanation of symbols]

[0122] 1...Steering control device 2...Steering gear 3. Steering wheel 5…Steering wheel 70...Steering side control unit 80...Steering side control unit 100…Main power supply 120,120S,120T…Auxiliary power supply device 121…Auxiliary power supply 126,127...Diode 128...Auxiliary power supply control unit 140,140S,140T…Signal line S, SS, ST...Power supply system

Claims

1. A control unit for the device that operates using power supplied from a main power source that is a DC power source to control the operation of the device to perform a desired function; an auxiliary power supply which is a DC power supply provided separately from the main power supply and which functions to assist the supply of power to the control unit for the device depending on the state of the power supply from the main power supply; a control unit for the auxiliary power supply that operates to control a state of power supply from the auxiliary power supply to a control unit for the device so as to perform the assistance; the control unit for the device is configured to be able to output information of the control unit for the device to the control unit for the auxiliary power supply, the main power supply is brought into a state of supplying power to a control unit for the device when a start-up switch for turning on and off a function of the device mounted on the device is turned on, and is brought into a state of stopping the supply of power to the control unit for the device when the start-up switch is turned off; the auxiliary power supply provides the auxiliary power by backing up the supply of power to a control unit for the device in place of the main power supply on the condition that the power supplied by the main power supply is reduced, and is configured to create a situation in which the control unit for the device continues to operate by backing up the supply of power to the control unit for the device even if the start-up switch is turned off; the control unit for the device is configured to receive information indicating the on / off state of the start-up switch from an external control unit provided at a location where the device is mounted, separate from the control unit for the device and the control unit for the auxiliary power supply, in order to determine the on / off state of the start-up switch; the control unit for the device is configured to determine whether or not to stop the operation based on the on / off state of the start-up switch, to determine to stop the operation when the start-up switch is determined to be off, and to output information indicating that the operation is to be stopped to the control unit for the auxiliary power supply when the operation is to be stopped, A power supply system in which the control unit for the auxiliary power supply is configured to determine whether or not to stop operation using information input from the control unit for the device indicating that the control unit for the device will stop operating.

2. the control unit for the device and the control unit for the auxiliary power supply are configured to be able to use a power supply voltage as information indicating a state of power supply from the main power supply in order to determine whether the start switch is turned off; the control unit for the device has a function of detecting a voltage detected through a power line to which the main power supply is connected as the power supply voltage, 2. The power supply system according to claim 1, wherein the control unit for the auxiliary power supply has a function of monitoring the power supply voltage.

3. A power supply system as described in claim 1 or claim 2, further comprising a selection circuit provided between the main power supply and the auxiliary power supply and a control unit for the device, and configured to select the power supply between the main power supply and the auxiliary power supply, whichever has a higher voltage, in order to supply power to the control unit for the device.

4. The selection circuit includes: a first diode provided in a first power supply path that is a path when power from the main power source is supplied to a control unit for the device; 4. The power supply system according to claim 3, further comprising: a second diode provided in a second power supply path that is connected to a control unit for the device side of the first diode provided in the first power supply path and serves as a path for supplying power from the auxiliary power supply to the control unit for the device.

5. The power supply system according to any one of claims 1 to 4, wherein the device is a steering device mounted on a vehicle and functions to operate at least one of a steering wheel and steered wheels provided on the vehicle, and a control unit for the device is configured to control the operation of the steering device.

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