Steering control device

Abstract

To provide a steering control device that can increase probability of the completion of start sequence during the period from the time when vehicle starting operation is performed to the time when vehicle accelerating operation is performed.SOLUTION: A steering control device controls, in accordance with a steering state, a source of driving power to be applied to a steering mechanism of a vehicle. The steering control device has a micro computer. When a predetermined execution condition is satisfied (YES in step S102) in a case where a start switch of the vehicle is turned off, the micro computer executes starting sequence as a series of processing required to activate a steering system. The execution condition is that an action by a user when attempting to use the vehicle is detected.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a steering control device. [Background technology]

[0002] Steer-by-wire steering devices that separate power transmission between the steering wheel and the steered wheels are known. This steering device has a reaction motor, a turning motor, and a control device. The reaction motor generates a steering reaction force applied to a steering shaft. The turning motor generates a turning force that steers the steered wheels. When the vehicle is traveling, the control device generates a steering reaction force through control of the reaction motor, and steers the steered wheels through control of the turning motor.

[0003] For example, the control device in Patent Document 1 has a CPU (Central Processing Unit), a memory, and a power supply circuit. When the start switch of the vehicle is switched from off to on, the power supply circuit adjusts the voltage supplied from the on-board power supply to the steering control device to a voltage that enables the CPU to operate appropriately. The CPU operates when supplied with the voltage adjusted by the power supply circuit. The CPU executes various controls by executing programs stored in the memory at predetermined calculation cycles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-130957 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional steering device control devices, including the steering device of Patent Document 1, execute a startup sequence when a vehicle start operation is performed. The startup sequence refers to a series of processes required for the steering system to operate. The startup sequence process includes, for example, hardware checks and CPU initialization.

[0006] The more complicated the system is, such as a steer-by-wire steering device, the more processing is required for the startup sequence. This means that the time required from starting to completing the startup sequence becomes longer. Therefore, there is a concern that the startup sequence may not be completed between the time the driver of the vehicle starts the vehicle and the time the vehicle starts. [Means for solving the problem]

[0007] A steering control device that solves the above problem controls a source of driving force applied to a steering mechanism of a vehicle in accordance with a steering state. The steering control device has a control circuit that executes a start-up sequence, which is a series of processes required for operating the steering system, when a predetermined execution condition is satisfied while a start switch of the vehicle is turned off.

[0008] According to this configuration, when the start switch of the vehicle is off, if the determined execution condition is satisfied, the startup sequence is executed even before the start switch of the vehicle is turned on. This increases the likelihood that the startup sequence will be completed in the period from when the user of the vehicle turns on the start switch as a start operation of the vehicle to when the user starts the vehicle.

[0009] The steering control device may further include a detection circuit for detecting a sign that the vehicle will be used. When the start switch is turned off and the sign is detected through the detection circuit, the control circuit may determine that the execution condition is satisfied and execute the start sequence.

[0010] According to this configuration, when the start switch of the vehicle is off and a sign of vehicle use is detected, the start sequence is executed even before the start switch is turned on. This increases the likelihood that the start sequence will be completed in the period from when the user of the vehicle turns on the start switch to start the vehicle to when the user starts the vehicle.

[0011] In the above steering control device, the sign may be an action of a user who is about to use the vehicle. According to this configuration, it is possible to detect signs that the user will use the vehicle based on the user's actions.

[0012] In the above steering control device, the user's actions include approaching the vehicle, unlocking the door, opening the door, and Getting into the driver's seat of At least one of them may be used.

[0013] According to this configuration, a sign of vehicle use can be appropriately detected based on the actions that the user is likely to perform when using the vehicle. In the steering control device, the vehicle may have a main power supply and an auxiliary power supply for the main power supply as power supplies. When the sign is detected through the detection circuit with the start switch in an OFF state, the control circuit may execute the startup sequence using power from the auxiliary power supply if the capacity of the auxiliary power supply is sufficient to execute the startup sequence.

[0014] According to this configuration, the auxiliary power supply is used as the power supply when executing the start-up sequence, thereby reducing consumption of the main power supply. In the above steering control device, the control circuit may be configured to execute the startup sequence using power from the main power supply when the capacity of the auxiliary power supply is insufficient to execute the startup sequence.

[0015] According to this configuration, even if the capacity of the auxiliary power supply is insufficient, the start-up sequence can be executed at an appropriate timing. 。 Effect of the Invention

[0025] According to the steering control device of the present invention, it is possible to increase the probability that the start-up sequence will be completed between the time when the vehicle start operation is performed and the time when the vehicle start operation is performed. [Brief description of the drawings]

[0026] [Figure 1] 1 is a configuration diagram of a steer-by-wire type steering device in which a first embodiment of a steering control device is mounted. FIG. [Diagram 2] 1 is a block diagram of a steering control device and a power supply device according to a first embodiment. [Diagram 3] 5 is a flowchart showing a procedure of a preliminary start-up process performed by the steering control device of the first embodiment. [Figure 4] 10 is a flowchart showing a procedure of a preliminary start-up process performed by the steering control device of the second embodiment. [Diagram 5] 13 is a flowchart showing a procedure of a preliminary start-up process performed by a steering control device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] <First embodiment> A first embodiment of a steering control device will be described. As shown in Fig. 1, a vehicle steering device 10 has a steering shaft 12 connected to a steering wheel 11. The steering device 10 also has a steered shaft 14 extending in the vehicle width direction (left-right direction in Fig. 1). Left and right steered wheels 16, 16 are connected to both ends of the steered shaft 14 via tie rods 15, 15, respectively. The linear movement of the steered shaft 14 determines the steering angle θ of the steered wheels 16, 16. wThe steering shaft 12 and the steered shaft 14 constitute a steering mechanism of the vehicle.

[0028] <Configuration for generating steering reaction force: reaction force unit> The steering device 10 has a reaction force motor 31, a reduction gear mechanism 32, a rotation angle sensor 33, and a torque sensor 34 as components for generating a steering reaction force. Incidentally, the steering reaction force is a force acting in a direction opposite to the direction of operation of the steering wheel 11 by the driver. By applying the steering reaction force to the steering wheel 11, it is possible to give the driver an appropriate sense of responsiveness.

[0029] The reaction motor 31 is a generating source of the steering reaction force. For example, a three-phase brushless motor is adopted as the reaction motor 31. The rotating shaft of the reaction motor 31 is connected to the steering shaft 12 via a reduction mechanism 32. The torque of the reaction motor 31 is applied to the steering shaft 12 as a steering reaction force. The torque of the reaction motor 31 is a driving force applied to the steering shaft 12.

[0030] The rotation angle sensor 33 is provided on the reaction motor 31. The rotation angle sensor 33 detects the rotation angle θ of the reaction motor 31. a The rotation angle θ of the reaction motor 31 is detected. a is the steering angle θ s The reaction motor 31 and the steering shaft 12 are linked via a reduction gear mechanism 32. Therefore, the rotation angle θ a and the steering angle θ which is the rotation angle of the steering shaft 12 and thus the rotation angle of the steering wheel 11. s Therefore, the rotation angle θ of the reaction force motor 31 is a Based on the steering angle θ s can be sought.

[0031] The torque sensor 34 detects the steering torque T h Detects the steering torque T his a torque applied to the steering shaft 12 through the rotation of the steering wheel 11. The torque sensor 34 detects the steering torque T applied to the steering shaft 12 based on the amount of twist of a torsion bar provided midway along the steering shaft 12. h The torque sensor 34 is provided on the steering shaft 12 at a portion between the speed reducer 32 and the steering wheel 11.

[0032] <Configuration for generating steering force: steering unit> The steering device 10 has a steering motor 41, a reduction gear mechanism 42, and a rotation angle sensor 43 as components for generating a steering force that is the power for steering the steered wheels 16, 16.

[0033] The steering motor 41 is a source of steering force. For example, a three-phase brushless motor is used as the steering motor 41. The rotating shaft of the steering motor 41 is connected to a pinion shaft 44 via a reduction mechanism 42. Pinion teeth 44a of the pinion shaft 44 mesh with rack teeth 14b of the steering shaft 14. The torque of the steering motor 41 is applied to the steering shaft 14 via the pinion shaft 44 as a steering force. The torque of the steering motor 41 is a driving force applied to the steering shaft 14. In response to the rotation of the steering motor 41, the steering shaft 14 moves along the vehicle width direction, which is the left-right direction in FIG. 1.

[0034] The rotation angle sensor 43 is provided on the steering motor 41. The rotation angle sensor 43 detects a rotation angle θ b Detect. Incidentally, the steering device 10 has a pinion shaft 13. The pinion shaft 13 is provided so as to intersect with the steered shaft 14. The pinion teeth 13a of the pinion shaft 13 mesh with the rack teeth 14a of the steered shaft 14. The reason for providing the pinion shaft 13 is to support the steered shaft 14 together with the pinion shaft 44 inside a housing (not shown). That is, the steered shaft 14 is supported movably along its axial direction by a support mechanism (not shown) provided in the steering device 10, and is pressed toward the pinion shafts 13 and 44. In this way, the steered shaft 14 is supported inside the housing. However, another support mechanism for supporting the steered shaft 14 in the housing may be provided without using the pinion shaft 13.

[0035] <Steering control device> The steering device 10 has a steering control device 50 and a power supply device 51. The steering control device 50 is connected to a main power supply 52 mounted on the vehicle via the power supply device 51. As the main power supply 52, for example, a battery is adopted. The steering control device 50 operates by consuming power from the main power supply 52 supplied via the power supply device 51.

[0036] Steering control device 50 controls reaction force motor 31 and steering motor 41 based on the detection results of various sensors mounted on the vehicle. The sensors include rotation angle sensor 33, torque sensor 34 and rotation angle sensor 43 described above, as well as vehicle speed sensor 501. Vehicle speed sensor 501 detects vehicle speed V.

[0037] The steering control device 50 controls the reaction motor 31 to generate a steering torque T h The steering control device 50 executes a reaction force control to generate a steering reaction force according to the steering torque T h and the vehicle speed V, and calculates a steering reaction force command value based on the calculated target steering reaction force. The steering control device 50 supplies, to the reaction force motor 31, a current required to generate a steering reaction force corresponding to the steering reaction force command value.

[0038] The steering control device 50 executes steering control for steering the steered wheels 16, 16 in accordance with the steering state through control of the steering motor 41. The steering control device 50 controls the steering motor 41 based on the rotation angle θ b Based on this, the actual rotation angle of the pinion shaft 44, that is, the pinion angle θ p This pinion angle θ p is the steering angle θ of the steered wheels 16, 16 w The steering control device 50 also detects the rotation angle θ of the reaction force motor 31 detected through the rotation angle sensor 33. a Based on the steering angle θ s The calculated steering angle θ s Based on the pinion angle θ p Then, the steering control device 50 calculates a target pinion angle, which is a target value of the target pinion angle θ p The deviation between the detected value and the actual value is calculated, and the power supply to the steering motor 41 is controlled so as to eliminate the deviation.

[0039] <Power supply unit details> Next, the configuration of the power supply device will be described in detail. 2, power supply device 51 is connected to a main power supply 52 via two power supply lines L1 and L2. Power supply device 51 has a charging circuit 51A, an auxiliary power supply 51B, a switching circuit 51C, and a voltage sensor 51D.

[0040] The charging circuit 51A and the auxiliary power supply 51B are located on the power supply line L1 inside the power supply device 51. The power supply line L1 is connected to the switching circuit 51C via the charging circuit 51A and the auxiliary power supply 51B. The switching circuit 51C is also connected to the main power supply 52 via the power supply line L2. The power supply line L2 is connected between a connection point P1 on the power supply line L1 and the switching circuit 51C. The connection point P1 is set between the main power supply 52 and the charging circuit 51A on the power supply line L1. The switching circuit 51C is also connected to the steering control device 50 via the power supply line L3.

[0041] The charging circuit 51A is a circuit for charging the auxiliary power supply 51B. The charging circuit 51A has, for example, a boost circuit that boosts the output voltage of the main power supply 52. ​​The charging circuit 51A operates based on a command from the steering control device 50.

[0042] The auxiliary power supply 51B is a power storage device capable of charging and discharging electric charge, and for example, a lithium ion capacitor is adopted. The voltage of the auxiliary power supply 51B is set to a value higher than the lower limit of the voltage required for the steering control device 50 to operate appropriately and lower than the voltage of the main power supply 52, for example.

[0043] Voltage sensor 51D detects the voltage of auxiliary power supply 51 B. When a lithium ion capacitor is used as auxiliary power supply 51 B, the voltage of auxiliary power supply 51 B is the voltage between the terminals of the lithium ion capacitor.

[0044] The switching circuit 51C switches the power source between the main power source 52 and the auxiliary power source 51B based on a command from the steering control device 50. The power of the main power source 52 or the power of the auxiliary power source 51B switched by the switching circuit 51C is supplied to the steering control device 50 via a power line L3. In addition, the power of the main power source 52 or the power of the auxiliary power source 51B switched by the switching circuit 51C is supplied to each part of the vehicle via a power line (not shown).

[0045] <Detailed configuration of steering control device> Next, the configuration of the steering control device will be described in detail. As shown in FIG. 2, the steering control device 50 has a microcomputer 50A, a drive circuit 50B, and a detection circuit 50C.

[0046] The drive circuit 50B has two inverters 50B1 and 50B2. These inverters 50B1 and 50B2 convert the DC power of the main power supply 52 or the DC power of the auxiliary power supply 51B supplied via the power supply line L3 into AC power. The operation of each of the inverters 50B1 and 50B2 is controlled by the microcomputer 50A.

[0047] The microcomputer 50A executes various processes according to programs stored in a storage device (not shown). The microcomputer 50A has a processor such as a CPU (Central Processing Unit). The processor centrally controls the entire steering device 10 through the execution of computer programs deployed in a working area of ​​the storage device. The microcomputer 50A is a control circuit.

[0048] The microcomputer 50A controls the charging of the auxiliary power supply 51B through the control of the charging circuit 51A. The microcomputer 50A detects the capacity of the auxiliary power supply 51B based on the voltage of the auxiliary power supply 51B detected by the voltage sensor 51D. The microcomputer 50A switches the power supply between the main power supply 52 and the auxiliary power supply 51B through the control of the switching circuit 51C.

[0049] The microcomputer 50A receives an electric signal S generated by a start switch 53 of the vehicle. st The start switch 53 is, for example, an ignition switch or a power switch. The start switch 53 is operated to start or stop a driving source for running the vehicle, such as an engine. The start switch 53 is also operated to switch the power position of the vehicle. The electric signal S st The electrical signal S indicates whether the start switch 53 is on or off, i.e., whether the power supply to the vehicle is on or off. st Also indicates whether the start switch 53 has been operated to start the driving source for traveling.

[0050] The microcomputer 50A has a reaction force control unit 50A1. The reaction force control unit 50A1 executes reaction force control. The reaction force control unit 50A1 controls the steering torque T hand vehicle speed V. The reaction force control unit 50A1 calculates a steering reaction force command value with a larger absolute value as the absolute value of the steering torque Th increases and as the vehicle speed V decreases. The reaction force control unit 50A1 supplies power according to the steering reaction force command value to the reaction force motor 31 through control of the inverter 50B1. This causes the reaction force motor 31 to generate torque according to the steering reaction force command value. The reaction force control unit 50A1 also calculates a steering reaction force command value based on the rotation angle θ of the reaction force motor 31 detected through the rotation angle sensor 33. a Based on this, the steering angle θ of the steering wheel 11 is s Calculate the following.

[0051] The microcomputer 50A has a steering control unit 50A2. The steering control unit 50A2 executes steering control. The steering control unit 50A2 controls the steering angle θ s The target pinion angle is calculated based on the vehicle speed V detected by the vehicle speed sensor 501. The steering control unit 50A2 controls the steering angle θ s The steering angle θ w The steering control unit 50A2 sets a steering angle ratio, which is the ratio of the steering angle θ s The steering angle θ w As the vehicle speed V increases, the steering angle θ s The steering angle θ w The steering control unit 50A2 calculates the target pinion angle so that the rotation angle θ b Based on this, the pinion angle θ p The steering control unit 50A2 calculates the pinion angle θ p The pinion angle θ p The pinion angle command value is calculated through feedback control of the above. Steering control unit 50A2 supplies electric power according to the pinion angle command value to steering motor 41 through control of inverter 50B2. As a result, steering motor 41 rotates by an angle according to the pinion angle command value.

[0052] The detection circuit 50C detects a sign that the vehicle will be used. The detection circuit 50C detects at least one of the following five events (A1) to (A5). These events (A1) to (A5) are events that indicate a sign that the vehicle will be used, and serve as a trigger for starting execution of a preliminary start-up process of the steering system, which will be described later. When a sign that the vehicle will be used is detected, the detection circuit 50C outputs a trigger signal S t Generates a trigger signal S t is an electrical signal that triggers the start of execution of a preliminary start-up process of the steering system.

[0053] (A1) Approaching the user's vehicle When a vehicle is equipped with an electronic key system, the vehicle communicates wirelessly with a portable terminal carried by a user. The vehicle control device forms a communication area inside and outside the vehicle by wirelessly transmitting a response request to the inside and outside of the vehicle. The vehicle control device determines the location of the portable terminal by receiving a response to the response request. When the response from the portable terminal is authenticated, the vehicle control device allows the door to be unlocked. The detection circuit 50C is capable of detecting the approach of a user to the vehicle based on the result of the determination of the location of the portable terminal by the vehicle control device.

[0054] (A2) Unlocking the door If the vehicle is equipped with an electronic key system, the vehicle control device unlocks the doors when it detects the operation of the door handle or door switch while the door unlocking is permitted. The mobile terminal also wirelessly transmits an unlocking request through the unlocking operation. The vehicle control device unlocks the doors when the authenticity of the unlocking request from the mobile terminal is authenticated. The detection circuit 50C can detect the unlocking of the doors based on the execution result of the door unlocking control by the vehicle control device.

[0055] (A3) Opening the door The open / closed state of the door is detected by a door courtesy switch mounted on the vehicle. The detection circuit 50C is capable of detecting the open / closed state of the door based on the detection result of the courtesy switch.

[0056] (A4) Sitting in the driver's seat Whether or not the user is seated in the driver's seat is detected by a seat sensor provided in the driver's seat. The detection circuit 50C can detect that the user is seated in the driver's seat based on the detection result of the seat sensor.

[0057] (A5) Establishment of biometric authentication It is considered that a biometric authentication system is installed in a vehicle in order to further improve the crime prevention performance of the vehicle. Biometric authentication refers to an authentication method in which a user's physical characteristics are digitized and used for identity verification. Examples of the user's physical characteristics include a fingerprint, facial characteristics, iris, voice, or palm. When biometric authentication is established via an authentication device inside or outside the vehicle, the vehicle control device allows the door to be unlocked or the drive source for running the vehicle to be started. The detection circuit 50C can detect the success or failure of biometric authentication through the authentication device.

[0058] <Preliminary start-up process for the steering system> When the start switch 53 is off, the microcomputer 50A executes a preliminary start-up process for the steering system. When the start switch 53 of the vehicle is off, the microcomputer 50A executes a preliminary start-up process for the steering system, for example, by consuming power from the main power supply 52. ​​When the microcomputer 50A uses the main power supply 52 as a power supply, i.e., when the auxiliary power supply 51B is not used as a power supply, the microcomputer 50A sets the value of the flag to "L". When the microcomputer 50A uses the auxiliary power supply 51B as a power supply, the microcomputer 50A sets the value of the flag to "H".

[0059] As shown in the flowchart of FIG. 3, the microcomputer 50A executes trigger sensing (step S101). That is, the microcomputer 50A executes detection processing of a trigger event, which is an event that triggers the start of execution of a preliminary startup processing of the steering system, through the detection circuit 50C. The trigger event to be detected is at least one of the above five events (A1) to (A5). The trigger event to be detected is set to a single event or multiple events depending on the product specifications.

[0060] Next, the microcomputer 50A judges whether or not it is necessary to start up the steering system (step S102). The microcomputer 50A judges whether or not it is necessary to start up the steering system based on whether or not a determined execution condition is satisfied. The execution condition is that the detection circuit 50C detects a trigger event to be detected, that is, the trigger signal S generated by the detection circuit 50C is detected. t is incorporated.

[0061] The microcomputer 50A receives a trigger signal S t When the trigger signal S is not received, it is determined that the steering system does not need to be started (NO in step S102), and the process proceeds to step S101. t When the steering system start command is received, it is determined that the steering system needs to be started, and the process proceeds to step S103 (YES in step S102).

[0062] In step S103, the microcomputer 50A determines whether the auxiliary power supply 51B is available. When the capacity of the auxiliary power supply 51B is sufficient to execute the startup process of the steering system, the microcomputer 50A determines that the auxiliary power supply 51B is available (YES in step S103). When the capacity of the auxiliary power supply 51B is insufficient to execute the startup process of the steering system, the microcomputer 50A determines that the auxiliary power supply 51B is not available (NO in step S103). The microcomputer 50A determines whether the capacity of the auxiliary power supply 51B is equal to or greater than the required capacity, for example, by comparing the voltage of the auxiliary power supply 51B detected by the voltage sensor 51D with a threshold voltage.

[0063] When the auxiliary power supply 51B is available (YES in step S103), the microcomputer 50A sets the value of the flag to "H" (step S104), and proceeds to step S105.

[0064] In step S105, the microcomputer 50A starts executing a start-up sequence. The start-up sequence is a series of processes required for the steering system to operate. The order of the processes performed in the start-up sequence is set in advance.

[0065] The processes performed in the startup sequence include, for example, hardware checks and CPU initialization. These processes include an initial check that is a check before starting power supply to reaction force motor 31 and steering motor 41. The hardware to be checked is, for example, inverters 50B1, 50B2.

[0066] The processing performed in the startup sequence also includes processing for correcting the rotational position of the steering wheel 11 so that the positional relationship between the steering wheel 11 and the steered wheels 16 becomes the original positional relationship according to a predetermined steering angle ratio. The steering angle ratio refers to the ratio between the steering angle of the steering wheel and the steered angle of the steered wheels.

[0067] In the steer-by-wire steering device 10, the steering wheel 11 is not restricted by the steering mechanism. Therefore, when some external force is applied to the steering wheel 11 while the power supply of the vehicle is turned off, the steering wheel 11 may rotate. At this time, the steered wheels 16 do not move, and a situation occurs in which the positional relationship between the steering wheel 11 and the steered wheels 16 differs from the original positional relationship according to a predetermined steering angle ratio. For this reason, the steering control device 50 executes a correction process for the rotational position of the steering wheel 11. The steering control device 50 stores the rotational position of the steering wheel 11 when the power supply of the vehicle is turned off. The steering control device 50 calculates the deviation amount of the rotational position of the steering wheel 11 by comparing the rotational position of the steering wheel 11 when the power supply of the vehicle is turned off with the current rotational position of the steering wheel 11 when the start-up sequence is started to be executed. The steering control device 50 controls the drive of the reaction force motor 31 so that the deviation amount of the rotational position of the steering wheel 11 becomes "0".

[0068] After completing the execution of the start-up sequence, the microcomputer 50A judges whether or not the user has performed an operation to start the vehicle (step S106). The operation to start the vehicle refers to the operation of the start switch 53 to start the drive source for running the vehicle. The microcomputer 50A detects an electric signal S generated by the start switch 53. st When it is determined that the user has performed an operation to start the vehicle (YES in step S106), the microcomputer 50A determines whether the value of the flag is “H” (step S107).

[0069] When the value of the flag is "H" (YES in step S107), the microcomputer 50A switches the power source from the auxiliary power source 51B to the main power source 52 through the switching circuit 51C (step S108). After that, the microcomputer 50A starts charging the auxiliary power source 51B through the charging circuit 51A (step S109) and ends the process. The microcomputer 50A also ends the process when the value of the flag is not "H" (NO in step S107).

[0070] When it is determined in step S106 that the user has not performed the start operation of the vehicle (NO in step S106), the microcomputer 50A determines whether or not the set time has elapsed (step S110). The criterion for starting the measurement of the set time is, for example, the time when the execution of the start sequence in step S105 is completed or the time when it is first determined in step S106 that the user has not performed the start operation of the vehicle.

[0071] If the set time has not elapsed (NO in step S110), the microcomputer 50A proceeds to the previous step S106. If the set time has elapsed (YES in step S110), the microcomputer 50A sets the value of the flag to "L" (step S111) and proceeds to step S112.

[0072] In step S112, the microcomputer 50A starts executing a termination sequence. The termination sequence refers to a series of processes required to normally terminate the function of the steering system. The order of the processes performed in the termination sequence is set in advance. The processes performed in the termination sequence include, for example, a process of stopping a process being executed by the microcomputer 50A. The processes performed in the termination sequence also include, for example, a process of waiting until the process being executed by the microcomputer 50A is completed and storing data temporarily stored in the working area of ​​the storage device in the non-volatile storage area of ​​the storage device. After completing the execution of the termination sequence, the microcomputer 50A proceeds to the previous step S101.

[0073] When it is determined in the previous step S103 that auxiliary power source 51B is not in a usable state (NO in step S103), microcomputer 50A determines whether or not the user has performed an operation to start the vehicle (step S113).

[0074] When it is determined that the user has not performed the operation to start the vehicle (NO in step S113), the microcomputer 50A determines whether the set time has elapsed (step S114). When the set time has not elapsed (NO in step S114), the microcomputer 50A shifts the process to the previous step S113. When the set time has elapsed (YES in step S114), the microcomputer 50A shifts the process to the previous step S101.

[0075] The reference for starting measurement of the set time is, for example, the time when it is first determined in step S113 that the vehicle start operation has not been performed. The set time in step S113 is, for example, the same time as the set time in step S110.

[0076] When it is determined in step S113 that the user has started the vehicle (YES in step S113), the microcomputer 50A shifts the process to the previous step S105 and starts executing the start-up sequence. At this time, the main power supply 52 is used as the power supply.

[0077] <Advantages of the First Embodiment> Therefore, according to the first embodiment, the following effects can be obtained. (1-1) When a sign of vehicle use is detected with the start switch 53 off, the start sequence of the steering system is started before the user starts the vehicle. This increases the likelihood that the start sequence will be completed in the period from when the vehicle is started to when the vehicle is started. In other words, it is unlikely that the start sequence will be completed when the user tries to start the vehicle. This makes it possible to improve user convenience.

[0078] (1-2) When a sign of vehicle use is detected with start switch 53 off, if the capacity of auxiliary power supply 51B is sufficient to execute the startup sequence, auxiliary power supply 51B is used to power the processes performed in the startup sequence. When the user starts the vehicle, the power supply is switched from auxiliary power supply 51B to main power supply 52. ​​By using auxiliary power supply 51B to power the processes performed in the startup sequence, consumption of main power supply 52 is reduced.

[0079] (1-3) When a sign of vehicle use is detected with start switch 53 turned off and auxiliary power supply 51B does not have enough capacity to execute the startup sequence, main power supply 52 is used to power the startup sequence. Therefore, even if auxiliary power supply 51B does not have enough capacity, the startup sequence can be executed at an appropriate timing.

[0080] (1-4) When the user performs an operation to start the vehicle, the power source is switched from auxiliary power source 51B to main power source 52. Also, charging of auxiliary power source 51B starts. This makes it possible to prepare for the execution of the next startup sequence that uses auxiliary power source 51B.

[0081] (1-5) At least one of the following events is detected as a sign of vehicle use: a user's approach to the vehicle, a door being unlocked, a door being opened, a driver being seated, and biometric authentication being established. These events are actions that a user would necessarily perform when using a vehicle. Therefore, the sign of vehicle use can be appropriately detected.

[0082] (1-6) Depending on the product specifications, multiple trigger events are set as execution conditions for starting the steering system. A situation in which multiple trigger events occur is one in which the user is more likely to use the vehicle. For example, if only the approach of the user to the vehicle (event A1) is set as the trigger event, the following concerns arise. That is, the user may approach the vehicle for purposes other than use. In this case, the start-up sequence may be started even if the user has no intention of using the vehicle. In contrast, if the approach of the user to the vehicle (event A1) and the unlocking of the door (event A2) are set as the trigger events, the start-up sequence will not be executed unless the door is unlocked. In this way, by setting multiple trigger events, it is possible to prevent the start-up sequence from being executed unnecessarily.

[0083] <Second embodiment> Next, a second embodiment of the steering control device will be described. This embodiment basically has the same configuration as the first embodiment shown in Figs. 1 and 2. This embodiment differs from the first embodiment in a part of the preliminary start-up process of the steering system. Therefore, the same members and configurations as those in the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

[0084] As in the first embodiment, the microcomputer 50A executes a preliminary start-up process for the steering system when the start switch 53 of the vehicle is in an OFF state. As shown in the flowchart of FIG. 4, the microcomputer 50A executes the end sequence through each process of steps S101 to S111 (step S112). After completing the execution of the end sequence, the microcomputer 50A shifts the process to step S113. When it is determined that the user has performed an operation to start the vehicle (YES in step S113), the microcomputer 50A shifts the process to the previous step S105 and starts executing the start sequence. At this time, the main power source 52 is used as the power source.

[0085] <Advantages of the second embodiment> Therefore, according to the second embodiment, in addition to the effects (1-1) to (1-6) of the first embodiment, the following effects can be obtained.

[0086] (2-1) After the termination sequence has been completed, if the user starts the vehicle, microcomputer 50A starts executing the startup sequence using main power supply 52 as the power source. Even after the termination sequence has been completed, if the user starts the vehicle, the startup sequence can be started immediately.

[0087] <Third embodiment> Next, a third embodiment of the steering control device will be described. Depending on the product specifications, a configuration in which the power supply device 51 is omitted from the steering device 10 is adopted. When the start switch 53 is in an OFF state, the power of the main power supply 52 is supplied to the steering control device 50 via a power line such as a service line (not shown). Even when this configuration is adopted, the microcomputer 50A executes a preliminary start-up process of the steering system when the start switch 53 is in an OFF state, similarly to the first embodiment.

[0088] As shown in the flow chart of Fig. 5, the microcomputer 50A executes trigger sensing to detect a trigger event (step S101) and determines whether or not activation of the steering system is required (step S102). t When the trigger signal S generated by the detection circuit 50C is not received, it is determined that the steering system does not need to be started (NO in step S102), and the process proceeds to step S101. t When the steering system is detected, it is determined that the steering system needs to be started (YES in step S102), and the process proceeds to step S105.

[0089] In step S105, the microcomputer 50A starts executing the start-up sequence. After that, the microcomputer 50A determines whether or not the user has performed a start operation of the vehicle (step S106). When it is determined that the user has performed a start operation of the vehicle (YES in step S106), the microcomputer 50A ends the process.

[0090] When it is determined in step S106 that the user has not performed the vehicle start operation (NO in step S106), the microcomputer 50A determines whether or not a set time has elapsed (step S110). The criterion for starting the measurement of the set time is, for example, the time point at which the execution of the startup sequence in step S105 is completed.

[0091] If the set time has not elapsed (NO in step S110), the microcomputer 50A shifts the process to the previous step S106. If the set time has elapsed (YES in step S110), the microcomputer 50A shifts the process to step S112.

[0092] The microcomputer 50A starts executing the end sequence in step S112. After completing the execution of the end sequence, the microcomputer 50A shifts the process to the previous step S101.

[0093] The third embodiment may be modified as follows. That is, after completing the execution of the termination sequence in the previous step S112, the microcomputer 50A shifts the process to step S113. When it is determined that the user has performed the start operation of the vehicle (YES in step S113), the microcomputer 50A shifts the process to the previous step S105 and starts the execution of the start sequence.

[0094] <Advantages of the Third Embodiment> Therefore, according to the third embodiment, in addition to the effects of the first embodiment described above in (1-1), (1-5) and (1-6), the following effects can be obtained.

[0095] (3-1) Even if the steering device 10 does not have an auxiliary power supply device 51, the microcomputer 50A can execute a preliminary startup process for the steering system when the start switch 53 is in an OFF state.

[0096] (3-2) When the microcomputer 50A is configured to start the startup sequence using the main power supply 52 as the power source when the user starts the vehicle after the termination sequence has been completed, the following effect can be obtained: That is, even after the termination sequence has been completed, if the user starts the vehicle, the startup sequence can be immediately started.

[0097] <Other embodiments> The first to third embodiments may be modified as follows. In each embodiment, the main power supply 52 is used as the power supply when executing the processes (steps S101 and S103) for detecting a trigger event while the start switch 53 is in an OFF state. However, the auxiliary power supply 51B may be used instead.

[0098] When a user intends to use a vehicle, events occur in the order of at least event A1, event A2, event A3, and event A4. That is, when a user intends to drive a vehicle, the user approaches a parked vehicle (event A1) and unlocks the door (event A2). After this, the user opens the vehicle door (event A3) and sits in the driver's seat (event A4). The biometric authentication of event A5 is incorporated into a series of actions until the user starts driving the vehicle, depending on the product specifications. In light of this, for example, when any one of the five events (A1) to (A5) is set as the trigger event to be detected, the content of the process in the previous step S106 may be changed as follows.

[0099] That is, when the next trigger event to occur has not occurred even after the set time has elapsed after the completion of the execution of the start-up sequence in the previous step S105, the microcomputer 50A starts executing the end sequence (step 112). For example, if the execution condition for starting the steering system is set to be the user's approach to the vehicle (event A1) in the previous step S102, the next trigger event to occur is the door unlocking (event A2). Also, if the execution condition for starting the steering system is set to be the door unlocking (event A2) in the previous step S102, the next trigger event to occur is the door opening (event A3).

[0100] In each embodiment, the start-up sequence is started when a trigger event associated with the action of a user who is about to use the vehicle is detected, but the following may be done. That is, when the plan to use the vehicle is decided, the planned use of the vehicle may be reserved and registered in the vehicle. The planned use is, for example, the date and time when the vehicle is to be used. The reservation registration may be performed, for example, through wireless communication using a mobile terminal carried by the user, or through an input device in the vehicle cabin. The microcomputer 50A starts executing the start-up sequence of the steering system at the reserved date and time. This also increases the probability that the start-up sequence of the steering system will already be completed when the user tries to start the vehicle.

[0101] In each embodiment, the start-up sequence is started when a trigger event associated with the action of the user who is about to drive the vehicle is detected, but the following may be done. That is, the microcomputer 50A starts executing the start-up sequence of the steering system at a set cycle. This also increases the probability that the start-up sequence of the steering system will already be completed when the user tries to start the vehicle.

[0102] The reaction force control unit 50A1 and the steering control unit 50A2 may be separate control devices independent of each other. The steering device 10 may have a clutch. In this case, as shown by the two-dot chain line in Fig. 1, the steering shaft 12 and the pinion shaft 13 are connected via a clutch 21. As the clutch 21, an electromagnetic clutch that interrupts power by interrupting the supply of electricity to an exciting coil is used. The steering control device 50 executes an on-off control that switches the on-off state of the clutch 21. When the clutch 21 is disengaged, the power transmission between the steering wheel 11 and the steered wheels 16 is mechanically disconnected. When the clutch 21 is engaged, the power transmission between the steering wheel 11 and the steered wheels 16 is mechanically connected.

[0103] The steering device 10 may be an electric power steering device. In this case, the steering shaft 12 and the pinion shaft 13 are maintained in a state in which they are connected to each other. An assist force generated by an assist motor is applied to the steering shaft 12 or the steered shaft 14. The assist force is a force for assisting the steering of the steering wheel 11. The start-up sequence is also executed in the electric power steering device. [Explanation of symbols]

[0104] 12...Steering shaft constituting the steering mechanism 14...Steering shaft constituting the steering mechanism 31...Reaction motor (source of driving force) 41...Steering motor (source of driving force) 50...Steering control device 50A...Microcomputer (control circuit) 50C…Detection circuit 51B…Auxiliary power supply 52…Main power supply 53…Start switch

Claims

1. A steering control device that controls a source of a driving force applied to a steering mechanism of a vehicle in accordance with a steering state, a control circuit that executes a start sequence, which is a series of processes required for operating the steering system, when a predetermined execution condition is satisfied while a start switch of the vehicle is turned off; a detection circuit for detecting a sign that the vehicle will be used; the control circuit is configured to, when the start switch is turned off and the symptom is detected through the detection circuit, determine that the execution condition is satisfied and execute the start-up sequence; the vehicle has a main power supply and an auxiliary power supply for the main power supply as a power supply; The steering control device is configured such that when the start switch is turned off and the warning sign is detected through the detection circuit, and when the capacity of the auxiliary power supply is sufficient to execute the startup sequence, the control circuit executes the startup sequence using the power of the auxiliary power supply.

2. The steering control device according to claim 1 , wherein the sign is an action of a user who is about to use the vehicle.

3. The steering control device according to claim 2 , wherein the user's action is at least one of approaching the vehicle, unlocking a door, opening the door, and sitting in a driver's seat.

4. A steering control device as described in claim 1, wherein the indication is the establishment of biometric authentication.

5. A steering control device according to any one of claims 1 to 4, wherein the control circuit executes the startup sequence using power from the main power source when the capacity of the auxiliary power source is insufficient to execute the startup sequence.

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