Steering control device

Abstract

The present invention provides a steering control device. In the steering control device, a first circuit (68) energizes a steering assist actuator (800) that electrically assists a driver's steering operation. A second circuit (672, 673) is provided in the same housing (600) as the first circuit (68) and energizes one or more position system actuators (720, 730) that move the position of the steering device. A control unit (30) operates the first circuit (68) and the second circuit (672, 673) to control the operations of the steering assist actuator (800) and the position system actuators (720, 730). The control unit (30) changes a "priority" during a plurality of periods including a startup period, a normal operation period, and a stop period of the steering control device, where the "priority" is any one or more of the order in which the first circuit and the second circuit operate, the distribution of the outputs of the first circuit and the second circuit, or the magnitude of the outputs.

Description

[0001] Cross - reference to related applications

[0002] This application is based on Japanese Patent Application No. 2020 - 083885, filed on May 12, 2020, the content of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to a steering control device. Background art

[0004] Conventionally, there has been known a steering control device that shares a circuit of a polyphase rotary electric machine and a DC rotary electric machine related to driving and steering operation of a vehicle. For example, the motor control device disclosed in Patent Document 1 drives a three - phase motor for electric power steering (EPS) and DC motors for tilting and telescoping by one three - phase inverter drive circuit. By sharing the power converters of the three - phase motor and the DC motor, integration of the power converters is achieved.

[0005] Patent Document 1: Japanese Patent No. 5768999

[0006] In the present specification, as a term for the upper concept of a motor, an "actuator" including other than a motor is used. In a structure in which circuits for driving a plurality of actuators are provided in the same housing, since heat and power are concentrated along with the operation of each circuit, it is necessary to increase the thermal mass and heat dissipation of the circuit. Therefore, there are problems such as an increase in noise reduction elements, terminals of coils and capacitors, and enlargement of the housing. Summary of the invention

[0007] An object of the present disclosure is to provide a steering control device that achieves miniaturization of a housing in a steering control device in which circuits for driving a plurality of actuators are provided in the same housing.

[0008] The steering control device of the present disclosure includes a first circuit, one or more second circuits, and a control unit.

[0009] The first circuit energizes a steering operation assist actuator that electrically assists a driver's steering operation. The second circuit is provided in the same housing as the first circuit and energizes one or more position system actuators that move the position of the steering device. The control unit operates the first circuit and the second circuit to control the operations of the steering operation assist actuator and the position system actuator.

[0010] The control unit changes the "priority" during a plurality of periods including a period when the steering control device is started, that is, a "start - up period", a period when normal operation is performed, that is, a "normal operation period", and a period when it stops, that is, a "stop period". The so - called "priority" is any one or more of the order of operating the first circuit and the second circuit, the distribution of the outputs of the first circuit and the second circuit, or the magnitude of the outputs.

[0011] In the present disclosure, in a steering control device in which circuits for driving a plurality of actuators are provided in the same housing, the control unit operates the first circuit and the second circuit according to the order of operation, the priority of output allocation, or the magnitude of output, thereby efficiently driving the plurality of actuators. As a result, concentration of heat and power can be avoided, and the thermal mass and heat dissipation of the circuit can be suppressed. Therefore, the housing can be miniaturized.

[0012] For example, the control unit changes the priority according to the position of the steering device during startup. Specifically, when the steering device is in a position out of reach of the driver's hand during startup, the tilting and telescoping operation for moving the position of the steering device is prioritized. By moving the steering device to the memorized position, the driver can perform steering operation. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0014] Figure 1 FIG. is a diagram of a column-type EPS system to which an ECU (steering control device) of each embodiment is applied.

[0015] Figure 2 FIG. is a diagram of a rack-type EPS system to which an ECU (steering control device) of each embodiment is applied.

[0016] Figure 3 FIG. is a diagram of an SBW system to which an ECU (steering control device) of each embodiment is applied.

[0017] Figure 4A FIG. is a schematic diagram for explaining a tilting operation.

[0018] Figure 4B FIG. is a schematic diagram for explaining a telescoping operation.

[0019] Figure 5 FIG. is a diagram showing an example of a connection structure of a connector in the first embodiment.

[0020] Figure 6 FIG. is a diagram showing an example of a connection structure of a connector in the second embodiment.

[0021] Figure 7 FIG. is a diagram of Circuit Structure Example 1 of a motor drive circuit in the first embodiment.

[0022] Figure 8 FIG. is a diagram of Circuit Structure Example 2 of a motor drive circuit in the first embodiment.

[0023] Figure 9 FIG. is a diagram of Circuit Structure Example 3 of a motor drive circuit in the first embodiment.

[0024] Figure 10 It is a schematic diagram showing the structure of a three-phase double-winding rotating electrical machine.

[0025] Figure 11 It is a diagram of Structure Example 1 of the latch circuit for the drive circuit.

[0026] Figure 12 It is a diagram of Structure Example 2 of the latch circuit for the drive circuit.

[0027] Figure 13 It is a flowchart (1) showing the overall sequence.

[0028] Figure 14 It is a flowchart (2) showing the overall sequence.

[0029] Figure 15 It is a flowchart for determining the priority of each period in the first embodiment.

[0030] Figure 16 It is a flowchart for determining the priority of each period in the second embodiment.

[0031] Figure 17 It is a block diagram showing the operation mode corresponding to the priority. Detailed implementation mode

[0032] Hereinafter, a plurality of embodiments of the steering control device of the present disclosure will be described based on the accompanying drawings. The steering control device of each embodiment is applied to an electric power steering system (hereinafter "EPS system") or a steer-by-wire system (hereinafter "SBW system") of a vehicle and functions as an EPS-ECU or an SBW-ECU. In the following embodiments, the EPS-ECU or the SBW-ECU is collectively referred to as "ECU".

[0033] The steering control device of the first embodiment includes a first circuit for energizing a three-phase motor as a steering operation assist actuator, and a second circuit for energizing two DC motors as a tilt actuator and a telescopic actuator. The steering control device of the second embodiment further includes a third circuit for energizing a DC motor as a locking actuator. Hereinafter, the tilt actuator and the telescopic actuator are collectively referred to as "position system actuators" and are treated as actuators of the same type.

[0034] In other words, the first embodiment includes a first circuit and a second circuit that energize two types of actuators, namely, a steering assist actuator and a position system actuator. The second embodiment includes a first circuit, a second circuit, and a third circuit that energize three types of actuators, namely, a steering assist actuator, a position system actuator, and a locking actuator. The structure of the second embodiment includes the structure of the first embodiment. As the order of description in this specification, instead of moving to the description of the second embodiment after finishing the description of the first embodiment, the descriptions of the first embodiment and the second embodiment are carried out in parallel. The description is centered on the second embodiment according to the content, and the part obtained by removing the description related to the locking actuator from it is used as the description of the first embodiment. In addition, the first embodiment and the second embodiment are collectively referred to as "this embodiment".

[0035] [System Structure]

[0036] First, refer to Figures 1 to 4B to describe the "system structure with three types of actuators" of the ECU that applies the "steering control device" as the second embodiment. In Figure 1 , Figure 2 , an EPS system 901 in which the steering control mechanism and the steering mechanism are mechanically connected is shown. Among them, a column-type EPS system is shown in Figure 1 , and a rack-type EPS system 901 is shown in Figure 2 . When distinguishing, the reference numeral of the column-type EPS system is denoted as 901C, and the reference numeral of the rack-type EPS system is denoted as 901R. In Figure 3 , an SBW system 902 in which the steering control mechanism and the steering mechanism are mechanically separated is shown. In Figures 1 to 3 , only one side of the tire 99 is illustrated, and the illustration of the tire on the opposite side is omitted.

[0037] As shown in Figure 1 , Figure 2 , the EPS system 901 includes a steering wheel 91, a steering shaft 92, an intermediate shaft 95, a rack 97, etc. as the "steering device". The steering shaft 92 is included in the steering column 93, one end is connected to the steering wheel 91, and the other end is connected to the intermediate shaft 95.

[0038] At the end of the intermediate shaft 95 on the side opposite to the steering wheel 91, a steering rack 97 is provided that converts rotation into reciprocating motion through a rack and pinion mechanism and transmits it. If the steering rack 97 reciprocates, the tire 99 steers via the tie rod 98 and the knuckle arm 985. In addition, universal joints 961 and 962 are provided in the middle of the intermediate shaft 95. Thus, the displacement caused by the tilting action and telescopic action of the steering column 93 is absorbed.

[0039] In Figure 1In the column-type EPS system 901C shown, the steering assist actuator 800 composed of a three-phase motor as a "polyphase rotating motor" and the locking device 20 are both arranged on the steering column 93. The output torque of the steering assist actuator 800 is transmitted to the steering shaft 92. The torque sensor 94 is provided in the middle of the steering shaft 92 and detects the driver's steering torque Ts based on the torsional displacement of the torsion bar.

[0040] In Figure 2 In the rack-type EPS system 901R shown, the steering assist actuator 800 composed of a three-phase motor as a "polyphase rotating motor" and the locking device 20 are both arranged on the steering rack 97. The reciprocating motion of the steering rack 97 is assisted by the output torque of the steering assist actuator 800. The torque sensor 94 detects the driver's steering torque Ts transmitted to the steering rack 97.

[0041] The ECU 10 is activated by the on / off signal of the vehicle switch 11, etc. In addition, the vehicle switch 11 corresponds to the ignition switch and push-button switch of an engine vehicle, a hybrid vehicle, and an electric vehicle. Each signal to the ECU 10 is communicated using CAN, serial communication, etc., or sent as an analog voltage signal. In the EPS system 901, the ECU 10 controls the drive of the steering assist actuator 800 based on the steering torque Ts detected by the torque sensor 94 and the vehicle speed V detected by the vehicle speed sensor 14. The steering assist actuator 800 electrically assists the driver's steering operation.

[0042] The tilt actuator 720, the telescopic actuator 730, and the locking actuator 710 are composed of a DC motor as a "DC rotating motor". In the second embodiment, the steering assist actuator 800 and the two types of three DC motors are driven by a common control unit 30. In the first embodiment, the steering assist actuator 800 and the tilt actuator 720 and the telescopic actuator 730, which are one type of two DC motors, are driven by a common control unit 30. In the first embodiment, the locking actuator 710 may not be provided, or a structure independently driven by other devices may also be provided.

[0043] The tilt actuator 720 and the telescopic actuator 730 are arranged on the steering column 93. The tilt actuator 720 and the telescopic actuator 730 are both "steering device position system actuators" that move the position of the steering device. In this specification, the "steering device position system actuator" is abbreviated as the "position system actuator".

[0044] If an instruction of "rise / fall" is input to the ECU 10 by the driver operating the tilt switch 12, the ECU 10 instructs the tilt actuator 720 to perform a tilting action. Then, as Figure 4AAs shown, the tilt actuator 720 adjusts the tilt angle to move the steering wheel 91 up and down. Moreover, when the vehicle switch 11 is turned on and the vehicle starts, it moves to a pre-stored driving position, and when the vehicle switch 11 is turned off and the vehicle stops, it moves to the side where the driver's space becomes wider.

[0045] In addition, if an instruction of "extension / retraction" is input to the ECU 10 by the driver operating the telescopic switch 13, the ECU 10 instructs the telescopic actuator 730 to perform a telescopic action. Then, as Figure 4B shown, the telescopic actuator 730 adjusts the telescopic length to move the steering wheel 91 back and forth. Moreover, when the vehicle switch 11 is turned on and the vehicle starts, it moves to a pre-stored driving position, and when the vehicle switch 11 is turned off and the vehicle stops, it moves to the side where the driver's space becomes wider.

[0046] In this specification, the "steering lock actuator" is abbreviated as the "lock actuator" for omission. The lock actuator 710 performs locking by mechanically restricting the rotation of the steering device through driving the locking device 20 so that the steering wheel 91 does not rotate when parking or the like. The ECU 10 instructs the lock actuator 710 to release or re-lock the steering lock based on the on / off signal of the vehicle switch 11.

[0047] Next, as Figure 3 shown, in the SBW system 902 where the steering control mechanism and the steering mechanism are mechanically separated, there is no intermediate shaft 95 as compared to the EPS system 901. Driver input information such as the driver's steering operation torque Ts or the angle of the steering wheel 91 is electrically transmitted to the steering actuator 890 via the ECU 10. The rotation of the steering actuator 890 is converted into the reciprocating motion of the steering rack 97, and the tire 99 is steered via the tie rod 98 and the knuckle arm 985. In addition, although not shown in Figure 3 , there is a steering actuator ECU that drives the steering actuator 890 in response to the driver's steering wheel input.

[0048] In addition, in the SBW system 902, the driver cannot directly sense the reaction force to the steering operation. Therefore, the ECU 10 controls the drive of the reaction force actuator 800 to rotate the steering wheel 91 to impart a reaction force to the steering operation and give the driver an appropriate steering operation feeling.

[0049] In this specification, the reaction force imparted by the SBW system 902 is interpreted in a broad sense as the same concept as the steering operation assistance performed by the EPS system 901. Moreover, the "reaction force actuator" is included in the "steering operation assistance actuator that electrically assists the driver's steering operation".

[0050] In Figure 3In the SBW system 902, the position system actuators 720, 730, and the lock actuator 710 are used in the same way as Figure 1 the column-type EPS system 901C. Hereinafter, in the description of the steering assist actuator 800, the position system actuators 720, 730, and the lock actuator 710 based on the ECU 10, there is no difference between the EPS system 901 and the SBW system 902.

[0051] The ECU 10 of the first embodiment includes a "first circuit" 68, "second circuits" 672, 673, and a control unit 30, etc. The three-phase inverter circuit 68 as the "first circuit" energizes the steering assist actuator 800. The H-bridge circuits 672, 673 as the "second circuits" energize the tilt actuator 720 and the telescopic actuator 730, that is, two position system actuators. The three-phase inverter circuit 68 and the H-bridge circuits 672, 673 form a motor drive circuit. The control unit 30 operates the three-phase inverter circuit 68 and the H-bridge circuits 672, 673 to control the operations of the steering assist actuator 800 and the position system actuators 720, 730.

[0052] The ECU 10 of the second embodiment further includes a "third circuit" 671. The H-bridge circuit 671 as the "third circuit" energizes the lock actuator 710. The three-phase inverter circuit 68 and the H-bridge circuits 672, 673, 671 form a motor drive circuit. The control unit 30 operates the three-phase inverter circuit 68 and the H-bridge circuits 672, 673, 671 to control the operations of the steering assist actuator 800, the position system actuators 720, 730, and the lock actuator 710.

[0053] The control unit 30 includes a microcomputer, a drive circuit, etc., and has a CPU, a ROM, a RAM, an I / O, and a bus connecting these structures (not shown), etc., and executes control of software processing based on a program executed by the CPU and stored in a physical memory device such as the ROM (i.e., a readable non-transitory tangible recording medium) and hardware processing by a dedicated electronic circuit. Since the "first circuit" 68 and the "second circuits" 672, 673 are operated by the same microcomputer, it is easier to mediate priorities without considering communication delays and communication anomalies between microcomputers compared to the case of having multiple microcomputers.

[0054] The three-phase inverter circuit 68 and the H-bridge circuits 672, 673 of the first embodiment, or the three-phase inverter circuit 68 and the H-bridge circuits 672, 673, 671 of the second embodiment are provided in the same housing 600. Further, in Figures 1 to 3In the example, the control unit 30 is provided within the same housing 600 together with these motor drive circuits. Thereby, the ECU 10 can be integrated, and also, the wiring components such as wiring harnesses and connectors can be reduced. Further, in Circuit Structure Examples 1 and 3 described later (refer to Figure 7 , Figure 9 ), the wiring harnesses, connectors, etc. for electrically connecting to the positive and negative electrodes of the power supply Bt can be one or two.

[0055] However, in a structure where circuits for driving multiple actuators are provided within the same housing, since the heat and power accompanying the operation of each circuit are concentrated, it is necessary to increase the thermal mass and heat dissipation of the circuits. Therefore, there are problems such as an increase in noise reduction elements, terminals of coils and capacitors, and a larger-sized housing. Thus, in the present embodiment, in a steering control device where circuits for driving multiple actuators are provided within the same housing, miniaturization of the housing is achieved. The means for solving the problems will be described later.

[0056] Next, with reference to Figure 5 , Figure 6 , the connection structure of the devices will be described. The steering assist actuator 800 of the present embodiment is configured as a "mechatronic" brushless three-phase motor that integrally forms the ECU 10 on one side in the axial direction. On the other hand, each DC motor that functions as the position system actuators 720, 730, and the locking actuator 710 is connected to the ECU 10 via a connector. In other words, the connection between the steering assist actuator 800 and the ECU 10 is a fixed premise, whereas each DC motor 720, 730, 710 and the ECU 10 are configured to be connectable as an option according to need. For example, the circuit board on the ECU 10 side can be shared, and the specifications of the connectors and related electronic components can be post-set as options.

[0057] In Figure 5 , an example of the connector connection structure in the system of the first embodiment in which the tilt actuator 720 and the telescopic actuator 730, which are DC motors, are provided is shown. In this connection structure, a power system connector 591, a signal system connector 592, and a torque sensor connector 593 are separately provided. The power supply line (PIG) and the ground line from the DC power supply are connected to the power system connector 591. In addition to the control power supply line (IG) and the CAN communication line, the wirings of the tilt actuator 720 and the telescopic actuator 730 are also connected to the signal system connector 592. The power supply line, signal line, and ground line of the torque sensor 94 are commonly connected to the torque sensor connector 593.

[0058] The motor wires (M+, M−), the power supply wire of the position sensor, the signal wire of the position sensor, the ground wire are connected to the tilt actuator 720 and the telescopic actuator 730. By determining the arrival at a specified position using torque or current and time, and flowing a certain current or applying a voltage according to the on / off of the tilt switch 12 and the telescopic switch 13, it is also possible to have a structure without the position sensor power supply wire and the position sensor signal wire without using a position sensor. In Figure 5 signals can be received from the tilt switch 12 and the telescopic switch 13 through CAN communication or serial communication, and an analog voltage signal can also be received.

[0059] In addition, although the motor wires (M+, M−) of the position system actuators 720 and 730 are for the power system, since the motor current is smaller compared to the steering assist actuator 800, they can be included in the connection with the signal system connector 592. In the case where the current of the position system actuators 720 and 730 is large, it can also be another connector, or a connector shared with the power system connector 591 for the power supply wire (PIG) and the ground wire from the DC power supply. Additionally, the connectors can also be separated according to the position system actuators 720 and 730.

[0060] In Figure 6 an example of the connector connection structure in the system of the second embodiment in which a lock actuator 710 as a DC motor is also provided is shown. Regarding the Figure 5 structure, a signal wire for an authentication signal, a stop command, and the motor wires (M+, M−) of the lock actuator 710 are added to the signal system connector 592. The signal of the lock actuator 710 can also be separated from the connectors in the same way as the position system actuators 720 and 730.

[0061] [Example of the structure of the motor drive circuit]

[0062] Next, three circuit structure examples of the motor drive circuit in the first embodiment will be described with reference to Figures 7 to 10 . For the second embodiment, since only one same H-bridge circuit 671 is added in parallel with the H-bridge circuits 672 and 673, the illustration is omitted. First, regarding the steering assist actuator 800 which is the driving object of the three-phase inverter circuit 68, the unit including the three-phase winding and the three-phase inverter circuit corresponding to the winding is called a "system". Figure 7 , Figure 8 The circuit structure examples 1 and 2 shown are single-system structures, Figure 9 and the circuit structure example 3 shown is a dual-system structure. As Figure 10 shown, in the dual-system structure, the "first circuit" 68 is composed of two three-phase inverter circuits 681 and 682.

[0063] The three-phase winding of the single system structure is composed of winding wires 811, 812, and 813 of the U phase, V phase, and W phase connected at the neutral point N. A voltage is applied to the winding wires 811, 812, and 813 of each phase from the three-phase inverter circuit 68. A back electromotive force proportional to the product of the rotation speed and the sin value of the phase is generated in each phase. The back electromotive force generated in each phase is based on the voltage amplitude A, the rotation speed ω, and the phase θ, and is expressed by, for example, equations (1.1) to (1.3).

[0064] Eu=-Aωsinθ…(1.1)

[0065] Ev=-Aωsin(θ-120)…(1.2)

[0066] Ew=-Aωsin(θ+120)…(1.3)

[0067] The steering assist actuator 800 of the dual-system structure has two sets of three-phase windings 801 and 802. The three-phase winding 801 of the first system is composed of winding wires 811, 812, and 813 of the U1 phase, the V1 phase, and the W1 phase connected at the neutral point N1. A voltage is applied to the winding wires 811, 812, and 813 of each phase of the three-phase winding 801 of the first system from the three-phase inverter circuit 681 of the first system.

[0068] The second system three-phase winding 802 is formed by connecting winding wires 821, 822, 823 of U2 phase, V2 phase, and W2 phase at a neutral point N2. Voltage is applied to the winding wires 821, 822, 823 of each phase of the second system three-phase winding 802 from the second system three-phase inverter circuit 682.

[0069] like Figure 10 As shown, the steering assist actuator 800 of the dual-system structure forms two sets of three-phase windings 801 and 802 arranged on a coaxial dual-winding rotating motor. The electrical characteristics of the two sets of three-phase windings 801 and 802 are the same, for example, they are arranged on a common stator with an electrical angle of 30 [deg] offset from each other. In this case, the back electromotive force generated in each phase of the first system and the second system is based on the voltage amplitude A, the rotation speed ω, and the phase θ, for example, expressed by equations (2.1) to (2.3), (2.4a) to (2.6a).

[0070] Eu1=-Aωsinθ…(2.1)

[0071] Ev1=-Aωsin(θ-120)…(2.2)

[0072] Ew1=-Aωsin(θ+120)…(2.3)

[0073] Eu2=-Aωsin(θ+30)…(2.4a)

[0074] Ev2 = -Aωsin(θ - 90)…(2.5a)

[0075] Ew2 = -Aωsin(θ + 150)…(2.6a)

[0076] In addition, in the case where the phase relationships of the two systems are opposite, for example, the phase (θ + 30) of the U2 phase becomes (θ - 30). In this case, the back electromotive forces generated in each phase of the second system are represented by equations (2.4b) to (2.6b) instead of equations (2.4a) to (2.6a). And the phase difference equivalent to 30 [deg] is generally expressed as (30 ± 60×k) [deg] (k is an integer). Alternatively, the second system can also be arranged in the same phase as the first system.

[0077] Eu2 = -Aωsin(θ - 30)…(2.4b)

[0078] Ev2 = -Aωsin(θ + 90)…(2.5b)

[0079] Ew2 = -Aωsin(θ - 150)…(2.6b)

[0080] The position system actuators 720 and 730 driven by the H-bridge circuits 672 and 673 are composed of winding wires 724 and 734. When the tilt actuator 720 is energized, a back electromotive force E2 proportional to the rotational speed ω2 is generated. If the proportional constant is set as EA2, the back electromotive force E2 is expressed by the equation "E2 = -EA2ω2". In addition, the DC current supplied to the tilt actuator 720 is denoted as I2. When the telescopic actuator 730 is energized, a back electromotive force E3 proportional to the rotational speed ω3 is generated. If the proportional constant is set as EA3, the back electromotive force E3 is expressed by the equation "E3 = -EA3ω3". In addition, the DC current supplied to the telescopic actuator 730 is denoted as I3.

[0081] Next, the circuit structure examples 1 to 3 will be described in sequence. In Figure 7 In the ECU 101 of the circuit structure example 1 shown, for the common power supply Bt, the three-phase inverter circuit 68 and the two H-bridge circuits 672 and 673 are independently connected in parallel. The three-phase inverter circuit 68 and the H-bridge circuits 672 and 673 are connected to the positive electrode of the power supply Bt via the high-potential line Lp and to the negative electrode of the power supply Bt via the low-potential line Lg. The power supply Bt is, for example, a battery with a reference voltage of 12 [V]. The DC voltage input from the power supply Bt to the three-phase inverter circuit 68 is denoted as "input voltage Vri", and the DC voltage input to the H-bridge circuits 672 and 673 is denoted as "input voltage Vrd".

[0082] The three-phase inverter circuit 68 converts the DC power of the power supply Bt into three-phase AC power by the operation of a plurality of inverter switch elements IUH, IUL, IVH, IVL, IWH, and IWL on the high-potential side and the low-potential side connected by a bridge, and supplies power to the steering assist actuator 800. A capacitor Ci is provided between the high-potential line Lp and the low-potential line Lg on the power supply Bt side of the three-phase inverter circuit 68.

[0083] Specifically, the inverter switch elements IUH, IVH, and IWH are upper-arm elements provided on the high-potential side of the U phase, V phase, and W phase, respectively, and the inverter switch elements IUL, IVL, and IWL are lower-arm elements provided on the low-potential side of the U phase, V phase, and W phase, respectively. Hereinafter, the upper-arm element and the lower-arm element of the same phase are collectively denoted by the reference numerals "IUH / L, IVH / L, IWH / L". In addition, a set of high-potential side and low-potential side switch elements connected in series is referred to as a "bridge arm". "IUH / L" corresponds to the reference numeral of the U-phase bridge arm.

[0084] Current sensors SAU, SAV, and SAW for detecting the phase currents Iu, Iv, and Iw flowing in each phase are provided between the lower-arm elements IUL, IVL, and IWL of each phase of the three-phase inverter circuit 68 and the low-potential line Lg. The current sensors SAU, SAV, and SAW are composed of shunt resistors, for example.

[0085] On the current path between the power supply Bt and the capacitor Ci, a power relay Pir is connected in series on the power supply Bt side, and an inverse connection protection relay PiR is connected in series on the capacitor Ci side. The power relay Pir and the inverse connection protection relay PiR are composed of semiconductor switch elements such as MOSFETs or mechanical relays, etc., and can cut off the power supply from the power supply Bt to the three-phase inverter circuit 68 when opened. The power relay Pir cuts off the current in the flowing direction when the electrodes of the power supply Bt are connected in the normal direction. The inverse connection protection relay PiR cuts off the current in the flowing direction when the electrodes of the power supply Bt are connected in the direction opposite to the normal direction.

[0086] The H-bridge circuits 672 and 673 each include two bridge arms composed of four switch elements. One bridge arm of the H-bridge circuit 672 is composed of a high-potential side switch element 2Ha and a low-potential side switch element 2La, and the opposite bridge arm is composed of a high-potential side switch element 2Hb and a low-potential side switch element 2Lb. The tilt actuators 720 are connected between the midpoints of the respective bridge arms. One bridge arm of the H-bridge circuit 673 is composed of a high-potential side switch element 3Ha and a low-potential side switch element 3La, and the opposite bridge arm is composed of a high-potential side switch element 3Hb and a low-potential side switch element 3Lb. The telescopic actuators 730 are connected between the midpoints of the respective bridge arms.

[0087] In the tilt actuator 720, for example, the direction of the current I2 that flows when the switch elements 2Ha and 2Lb are turned on is defined as the positive direction, and the direction of the current I2 that flows when the switch elements 2Hb and 2La are turned on is defined as the opposite direction. The tilt actuator 720 rotates forward when energized in the positive direction and rotates backward when energized in the negative direction, performing a tilt operation of "rising / falling". Similarly, the telescopic actuator 730 rotates forward when energized in the positive direction and rotates backward when energized in the negative direction, performing a telescopic operation of "extending / contracting".

[0088] Current sensors SA2a and SA2b for detecting the DC current I2 are provided between the low-potential side switch elements 2La and 2Lb of each arm of the H-bridge circuit 672 and the low-potential line Lg. The current sensors SA2a and SA2b are constituted by shunt resistors, for example. The current sensors SA2a and SA2b may also be provided between the high-potential side switch elements 2Ha and 2Hb and the high-potential line Lp. Similarly, the H-bridge circuit 673 is also provided with current sensors SA3a and SA3b for detecting the DC current I3. A capacitor Cd is provided between the high-potential line Lp and the low-potential line Lg on the power supply Bt side of the H-bridge circuits 672 and 673. A power relay Pdr and an inverse connection protection relay PdR are connected in series in the current path between the power supply Bt and the capacitor Cd.

[0089] Each phase inverter switch element IUH / L, IVH / L, IWH / L of the three-phase inverter circuit 68 and each switch element of the H-bridge circuits 672 and 673 are, for example, MOSFETs. In addition, the switch elements may be field effect transistors other than MOSFETs, IGBTs, etc. Here, the current supplied to the position system actuators 720 and 730 is smaller than the phase current flowing in the steering assist actuator 800. Therefore, each switch element of the H-bridge circuits 672 and 673 may also use switches with a current capacity smaller than that of the inverter switch elements IUH / L, IVH / L, IWH / L. In addition, instead of high-speed switches, switches such as transistors with a slower conduction time or mechanical relays may be used.

[0090] In Figure 8 In the ECU 102 of the circuit structure example 2 shown, one arm of each of the H-bridge circuits 672 and 673 is shared with the U-phase arm of the three-phase inverter circuit 68. For convenience of illustration, the reference numerals "672" and "673" appear to refer to the non-shared side arms, but actually refer to the part that combines the U-phase arm of the three-phase inverter circuit 68 and the non-shared side arms. In the circuit structure example 2, the number of switch elements can be reduced compared to the circuit structure example 1.

[0091] In this way, in this specification, a power conversion circuit formed by sharing one arm (for example, the U phase) of the three-phase inverter circuit 68 and one arm on one side of each of the H-bridge circuits 672 and 673 is referred to as an "integrated power conversion circuit". In Circuit Structure Example 2, the single-system three-phase inverter circuit 68 and the H-bridge circuits 672 and 673 form an "integrated power conversion circuit 650". The control unit 30 does not operate the three-phase inverter circuit 68 and the H-bridge circuits 672 and 673 independently, but operates the integrated power conversion circuit 650 comprehensively.

[0092] The non-shared side arm of the H-bridge circuit 672 is composed of a high-potential side switching element MU2H and a low-potential side switching element MU2L connected in series via the DC motor terminal M2. The non-shared side arm of the H-bridge circuit 673 is composed of a high-potential side switching element MU3H and a low-potential side switching element MU3L connected in series via the DC motor terminal M3. Hereinafter, a set of switching elements constituting the non-shared side arm is referred to as a "DC motor switch". Similar to the inverter switching elements, the high-potential side and low-potential side switches are grouped, and the reference numerals of the DC motor switches are denoted as "MU2H / L, MU3H / L". The DC motor switches MU2H / L, MU3H / L can also use switches with a current capacity smaller than that of the inverter switching elements IUH / L, IVH / L, IWH / L, and can also be switches such as transistors or mechanical relays with a slower conduction time instead of high-speed switches.

[0093] In the example shown by the solid line, a first terminal T1, which is one end of each of the position system actuators 720 and 730, is connected to the branch point Ju of the U-phase current path of the three-phase winding. The opposite ends of the position system actuators 720 and 730 from the first terminal T1, that is, the second terminals T2, are connected to the DC motor terminal M2 between the DC motor switch MU2H / L and the DC motor terminal M3 between the DC motor switch MU3H / L. Each of the DC motor switches MU2H / L, MU3H / L is connected to the U-phase winding wire 811 via the position system actuators 720 and 730. In addition, as shown by the dotted line, for example, the first terminal T1 of the telescopic actuator 730 can also be connected to a branch point Jv of a different phase from the branch point Ju to which the first terminal T1 of the tilt actuator 720 is connected. In the reference numerals "MU2H / L, MU3H / L" of the DC motor switches, "U" refers to the U phase, and "2, 3" are the numbers of the DC motors.

[0094] In Circuit Structure Example 2, for the phase currents Iu, Iv, and Iw flowing in the three-phase inverter circuit 68, the phase currents that energize the three-phase winding are denoted as Iu#, Iv#, and Iw#. In Figure 8In the example, at the branch point Ju of the U-phase current path, a part of the phase current Iu is divided into the DC motor current I1. The relationship between the inverter phase currents Iu, Iv, Iw flowing on the three-phase inverter circuit 68 side of the branch point Ju and the motor phase currents Iu#, Iv#, Iw# energizing the steering assist actuator 800 side of the branch point Ju is expressed by formulas (3.1) to (3.4). In addition, the current I1 can be detected by configuring a sensor or a resistor. In the case of multiple DC motors, the respective currents can also be detected by configuring multiple resistors or by configuring a single resistor and staggering the switching-on timing.

[0095] Iu# = -Iv - Iw...(3.1)

[0096] Iv# = Iv...(3.2)

[0097] Iw# = Iw...(3.3)

[0098] I1 = Iu - Iu#...(3.4)

[0099] In each of the position system actuators 720 and 730, the direction of the current I1 from the first terminal T1 toward the second terminal T2 is defined as the positive direction, and the direction of the current I1 from the second terminal T2 toward the first terminal T1 is defined as the negative direction. Voltages Vx2 and Vx3 are applied between the first terminal T1 and the second terminal T2 of each of the position system actuators 720 and 730. Each of the position system actuators 720 and 730 rotates forward when energized in the positive direction and rotates in reverse when energized in the negative direction.

[0100] Assume a situation where, when the steering assist actuator 800 rotates at a high speed under a large force from the outside and generates a voltage greater than the power supply Bt, or when a certain failure occurs. Then, more preferably, when rotating in the positive direction, the position system actuators 720 and 730 move in the same direction relative to the driver. In other words, both approach the driver or both move away from the driver. Whether it is preferable to approach or move away depends on the maximum rotational speed and the magnitude of the displacement of the position system actuators 720 and 730.

[0101] In Figure 9 In the ECU 103 of the circuit structure example 3 shown, the "first circuit" 68 that energizes the steering assist actuator 800 (see the reference numeral Figure 10)It is composed of three-phase inverter circuits 681 and 682 of a dual system. The three-phase inverter circuit 681 of the first system is connected to the winding wires 811, 812, and 813 of the U1 phase, V1 phase, and W1 phase of the three-phase winding 801. The three-phase inverter circuit 682 of the second system is connected to the winding wires 821, 822, and 823 of the U2 phase, V2 phase, and W2 phase of the three-phase winding 802. In addition, the three-phase inverter circuits 681 and 682 of the dual system can also be controlled by different microcomputers respectively.

[0102] In the three-phase inverter circuit 681 of the first system, inverter switch elements IU1H / L, IV1H / L, IW1H / L and current sensors SAU1, SAV1, SAW1 for detecting the phase currents Iu1, Iv1, Iw1 of each phase are provided. A capacitor C1 is provided on the power supply Bt side of the three-phase inverter circuit 681. In addition, a power relay P1r and a reverse connection protection relay P1R are provided between the power supply Bt and the three-phase inverter circuit 681. The DC voltage input from the power supply Bt to the three-phase inverter circuit 681 is denoted as "input voltage Vr1". Phase currents Iu1#, Iv1#, Iw1# are applied to the three-phase winding 801. The reference numerals of the components of the second system and the notations of the currents are represented by replacing "1" in the reference numerals of the components of the first system and the notations of the currents with "2". In addition, for the components of the second system, the descriptions of the components of the first system are cited.

[0103] At the branch point Ju of the U1 phase current path of the three-phase winding 801 in the first system, one end, i.e., the first terminal T1, of each position system actuator 720, 730 is connected in the same way as in Circuit Structure Example 2. The ends, i.e., the second terminals T2, of the position system actuators 720, 730 on the side opposite to the first terminal T1 are connected to the DC motor terminal M2 between the DC motor switches MU2H / L and the DC motor terminal M3 between the DC motor switches MU3H / L. In the second embodiment, the locking actuator 710 can also be connected to the same U1 phase of the three-phase winding 801 in the first system, or can be connected to a different phase. Or, it can also be connected to one phase of the three-phase winding 802 in the second system. That is, the multiple DC motors 720, 730, 710 can all be connected to the same phase, or some or all of them can be connected to other phases.

[0104] In addition, one bridge arm on each side of the H-bridge circuits 672 and 673 is shared with the U1-phase bridge arm of the three-phase inverter circuit 681 of the first system. In this way, in Circuit Structure Example 3, the three-phase inverter circuits 681 and 682 and the H-bridge circuits 672 and 673 of the dual system form an "integrated power conversion circuit 660". The control unit 30 causes the integrated power conversion circuit 660 to operate comprehensively. By configuring in this way, it is possible to miniaturize by sharing bridge arms and increase the probability of continuing to assist with at least one system as a steering assist actuator.

[0105] [Latch Circuit]

[0106] Next, refer to Figure 11 , Figure 12 to show a structural example of the latch circuit for the drive circuit. In the sequence described later with reference to Figure 13 , Figure 14 the latch circuit is a circuit for self-holding even after the start signal is turned off after the microcomputer and ASIC of the ECU 10 are started. As the start signal, an IG (ignition) signal in a motor vehicle, a signal that is turned on triggered by unlocking or opening the door with a key, etc. can be used. As an example of the drive circuit, an example applied to the ECU 101 of Circuit Structure Example 1 is shown. The same can also be applied to the ECU 102 and 103 of Circuit Structure Examples 2 and 3 and drive circuits of other structures.

[0107] Figure 11 The latch circuit 410 of Structure Example 1 shown includes diodes Di and Dd whose anodes are connected to the high-potential line Lp after the power relays Pir and Pdr of the three-phase inverter circuit 68 and the H-bridge circuits 672 and 673, and a diode Dig whose anode is connected to the IG voltage source. First, if the IG voltage is applied to the microcomputer power supply 45 through the diode Dig, the microcomputer 40 starts.

[0108] According to an instruction from the microcomputer 40, the driver 411 composed of a semiconductor turns on at least one of the power relay Pir of the three-phase inverter circuit 68 or the power relay Pdr of the H-bridge circuits 672 and 673. If the power relay Pir of the three-phase inverter circuit 68 is turned on, the voltage Vri after the relay is applied to the microcomputer power supply 45 through the diode Di. If the power relay Pdr of the H-bridge circuits 672 and 673 is turned on, the voltage Vrd after the relay is applied to the microcomputer power supply 45 through the diode Di. After that, even if the input of the IG voltage stops, the voltage of the microcomputer power supply 45 is maintained as long as the power relays Pir and Pdr are not both turned off.

[0109] Figure 12The latch circuit 420 of Structural Example 2 shown includes drivers 421, 422 made of semiconductors and two switches Lta, Ltb. When the two switches Lta, Ltb are MOSFETs, the drain terminals are connected to the positive pole of the power supply Bt, and the source terminals are connected to the microcomputer power supply 45. The gate of one switch Lta is connected to the input terminal of the start signal or the IG voltage via the driver 421. The gate of the other switch Ltb is connected to the microcomputer 40 via the driver 422.

[0110] First, if a start signal or an IG voltage is input to the driver 421 and an on signal is output from the driver 421 to the gate of the switch Lta, the switch Lta turns on, and the voltage of the power supply Bt is applied to the microcomputer power supply 45. Therefore, the microcomputer 40 starts. If, according to an instruction from the microcomputer 40, the driver 422 outputs an on signal to the gate of the switch Ltb, the switch Ltb turns on, and the voltage of the power supply Bt is applied to the microcomputer power supply 45. After that, even if the input of the start signal or the IG voltage stops, as long as the on signal of the driver 422 is not turned off, the voltage of the microcomputer power supply 45 is maintained.

[0111] [Sequence]

[0112] Next, refer to Figure 13 、 Figure 14 to describe the overall sequence. This overall sequence is roughly divided into a start period, a normal operation period, and a stop period. The start period is the period when the ECU10 starts. The normal operation period is the period when the ECU10 performs normal operations. The stop period is the period when the ECU10 stops.

[0113] In the sequence, for the parts that vary according to the type of DC motor, the steps related to the position system actuators 720, 730 shared in the first and second embodiments are recorded in the solid-line frame on the left. In addition, the steps related to the locking actuator 710 added in the second embodiment are recorded in the dashed-line frame on the right. In addition, the Figure 11 、 Figure 12 latch circuits 410, 420 of Structural Example 1 and Structural Example 2 shown are denoted as "Latch Circuit I" and "Latch Circuit II" respectively. Hereinafter, the symbol "S" represents a step. In the description of the sequence, the reference numerals of each element are appropriately omitted.

[0114] If start signals such as an IG signal and a wake-up signal are turned on, the overall sequence starts. In S011, a microcomputer start sequence is executed, and in S012, a microcomputer / ASIC start sequence is executed. In S013, the latch signal of Latch Circuit II is turned on, and the self-holding state starts.

[0115] In S02, as the input circuit check (1), it is confirmed whether the power relay can be turned on. In S03, the cut-off function of the ASIC is detected. In S04, as the input circuit check (2), the remaining checks related to the input circuit are performed. The power relay is turned on in the middle of S04, and the self-holding state of the latch circuit I is started. In S05, the BLM circuit check is performed, and in S06, the DCM circuit check is performed. The "BLM (brushless motor) circuit" refers to the drive circuit of the three-phase motor, that is, the "first circuit", and the "DCM (DC motor) circuit" refers to the drive circuit of the DC motor, that is, the "second circuit".

[0116] After each check is performed, the control unit first operates the EPS during the startup period. However, when the steering device is in a position away from the driver, the tilt and telescopic actuators are prioritized. In S07T, the control unit starts the PWM drive of the EPS and the tilt. The EPS starts assisting if there is a steering operation torque input while waiting for the start of assistance. Moreover, if there is an input switch operation, the control unit starts the tilt. In S08T, the tilt and telescopic actuators move the steering wheel to the memory position (i.e., the driving position). If there is an input switch operation, the control unit stops the operation to the memory position and operates according to the switch operation.

[0117] In the second embodiment, further in S07R, after authentication, the steering lock is released. In S08R, the control unit waits for the start of EPS assistance while starting the PWM drive, and starts EPS assistance through the input of the steering operation torque.

[0118] In Figure 14 In S10, it is judged whether there is a start input from the CAN or the torque input is equal to or more than a specified value. If it is "yes", it moves to the normal operation. In addition, it is also possible not to wait for the start input from the CAN, but to move to the normal operation if waiting for the start of assistance. During the normal operation, in S19, the control unit starts EPS assistance with the input of the steering operation torque. In addition, the control unit starts the tilt through the input switch operation.

[0119] In S20, the start signal is turned on, the IG is turned off, or if a stop signal is received, it moves to the stop period. In S30 during the stop period, it is judged whether the vehicle speed condition and the engine speed satisfy the following conditions, for example. (a) The state where the vehicle speed is 0 [km / Hr] continues, (b) The state where both the engine speed and the vehicle speed are interrupted continues, (c) The vehicle speed is 0 [km / Hr] and the engine speed is 0 [rpm], etc. If it is judged as "yes" in S30, it moves to S31T or S31R.

[0120] After stopping the steering assist actuator during the stop period, the control unit operates the tilt and telescopic actuator. In S31T, the control unit stops EPS assistance. At this time, the control unit makes the current command for energizing the steering assist actuator 800 become 0. The bridge arm other than the shared one can also stop PWM drive and become a calculation standby. That is, it becomes a state of waiting for the start signal to turn on or the IG to be turned on, or the ECU or motor to cool down. In S32T, the tilt and telescopic actuator moves the steering wheel to a position away from the driver.

[0121] In the second embodiment, further, in S31R, the control unit stops EPS assistance. At this time, the control unit makes the current instruction for energizing the steering assist actuator 800 become 0. The bridge arm other than the shared one can also stop PWM drive and become a calculation standby. That is, it becomes a state of waiting for the start signal to turn on or the IG to be turned on, or the ECU or the motor to cool down. In S32R, the steering lock actuator is activated. In S32R, it is activated by waiting for the key to leave the vehicle or the door to be unlocked or opened.

[0122] After that, in S331, the control unit disconnects the power relay after waiting for the temperature of the circuit to drop as needed. In S332, the latch signal of the latch circuit II is turned off, and the self-holding state is released. In this way, the operation of the ECU stops. The above is the end of the entire sequence. In addition, the migration during the startup period, the normal operation period, and the stop period can also be performed as time passes, in addition to the migration based on the judgment results of S10, S20, and S30.

[0123] [Priority of drive circuit]

[0124] As a structure unique to this embodiment having a plurality of drive circuits for driving a plurality of actuators, the control unit 30 changes the "priority" of each drive circuit during a plurality of periods, namely, a startup period, a normal operation period, and a stop period. In the first embodiment, the so-called "priority" is any one or more of the order in which the first circuit and the second circuit are operated, the distribution of the outputs of the first circuit and the second circuit, or the size of the outputs. In the second embodiment, the control unit 30 further includes a "third circuit" to change the priority. The "priority" may be used only as a concept, and may not necessarily be set as an operation parameter of the control unit 30.

[0125] By determining the order of operation, it is possible to prevent unwanted interference between the actions of multiple actuators and perform correct operations. In addition, by operating the actuators one by one, the instantaneous maximum output can be suppressed. On the other hand, when multiple actuators are operated simultaneously, the output distribution or output size can be determined within the range of the maximum output that can be output, so that they can be operated efficiently.

[0126] The output allocation, for example, gives a difference to the output ratio commanded for the requested output for each actuator. For example, the control unit 30 operates with an output close to 100% relative to the requested output on the higher-priority side, and operates with only a part of the requested output on the lower-priority side. For example, assume that the requested output on the priority side is "40", the requested output on the non-priority side is "90", the commanded output on the priority side is mediated to "40", and the commanded output on the non-priority side is mediated to "60". In other words, it is not limited to simply increasing the number on the priority side. In contrast, in the magnitude of the output, the absolute output magnitude of each drive circuit is determined. In addition, the output allocation can also give a difference to the ratio as an effective value through time division or the like.

[0127] In particular, in a structure that shares a bridge arm as in Circuit Structure Examples 2 and 3 shown in Figure 8 , Figure 9 , since the sum of the currents flowing in the two actuators flows through the shared bridge arm and the upper limit of the voltage that can be applied to each actuator is determined by the sum of the two actuators, determining the priority is effective for miniaturization of the device. And, if they are in the same housing, it is effective to determine the priority from the viewpoint of sharing the thermal mass, and if the same connector is used, it is effective to determine the priority from the viewpoint of noise because the signals are close.

[0128] In Figure 15 , a flowchart for determining the priority in each period in the first embodiment is shown. During the start-up period, it is determined as "Yes" in S41. In this case, in S43, it is determined whether the steering device is in a position where the driver's hand cannot reach. When the steering device is in a position where the driver's hand cannot reach, the driver cannot perform a steering operation. Therefore, when it is "Yes" in S43, in S45, the tilt telescopic operation is prioritized. On the other hand, when the steering device is in a position where the driver's hand can reach, it is determined as "No" in S43, and in S46, the EPS is prioritized. In this way, the control unit 30 changes the priority according to the position of the steering device during the start-up period.

[0129] During the normal operation period, it is "No" in S41 and it is determined as "Yes" in S51. Since the tilt telescopic operation is mainly not performed during driving in normal operation, in this case, in S52, the EPS is prioritized.

[0130] During the stop period, it is "No" in S41 and S51, and it is determined as "Yes" in S61. In this case, before performing the tilt telescopic operation, in S62, the auxiliary stop of the EPS is prioritized. In addition, basically, there is no case where it does not conform to any of the start-up period, normal operation period, and stop period and it is determined as "No" in S61 as shown by the dashed line in the flowchart.

[0131] In Figure 16 , a flowchart for determining the priority of each period in the second embodiment is shown. The same step numbers are marked in the steps shared with Figure 15 and the description is omitted. During the startup period, it is determined in S42 whether the steering device is in a locked state. When the steering device is in the locked state, the driver cannot perform a steering operation. Therefore, when the result in S42 is "Yes", the release operation of the steering lock is prioritized in S44. On the other hand, when it is not in the locked state, the result in S42 is "No", and the process moves to S43. In this way, the control unit 30 changes the priority according to the state of the lock actuator 710 during the startup period.

[0132] In Figure 17 , a block diagram of the control unit 30 of the second embodiment is shown. In the first embodiment, the module for controlling the drive of the lower-stage lock actuator 710 is removed. The control unit 30 has mediation processing units 33, 38, and 35 for mediating actions according to the priorities of the respective drive circuits 68, 672, 673, and 671. In addition, the control unit 30 has a mediation processing unit 39 for mediating the total value of the duty ratios of the respective actuators. For example, the mediation processing unit 39 limits the total value of the duty ratios of the steering assist actuator 800 and the position system actuators 720 and 730, that is, the total value of the applied voltages, to be less than a specified value according to the priority.

[0133] The control unit 30 has an assist control unit 32, a mediation processing unit 33, and a current control unit 34 as modules for controlling the drive of the steering assist actuator 800. The assist control unit 32 calculates a current command based on the input of the steering operation torque Ts. The mediation processing unit 33 generates a mediated current command to not limit the current command when EPS is prioritized and to limit the absolute value of the current command according to the current limit value when EPS is not prioritized. The current control unit 34 calculates a drive signal through current feedback control based on the mediated current command and outputs it to the three-phase inverter circuit 68 as the "first circuit".

[0134] The control unit 30 has a duty ratio command unit 37 and a mediation processing unit 38 as modules for controlling the drive of the position system actuators 720 and 730. When an ON signal of an input switch is input, the duty ratio command unit 37 sets a time profile of the duty ratio command. Although the duty ratio can be immediately increased, it is more preferable to set the duty ratio to increase from 0 to a specified value, maintain it for a specified time, and then return to 0. Also, depending on the forward and reverse directions of the actuator, the duty ratio can be set to decrease from 100 to a specified value, maintain it for a specified time, and then return to 100.

[0135] The mediation processing unit 38 does not limit the operation when tilt expansion / contraction is prioritized, and limits the duty ratio when EPS is prioritized or steering lock is prioritized. For example, when EPS is prioritized, the mediation processing unit 38 can also limit the duty ratio according to the EPS output. A drive signal based on the mediated duty ratio is output to the H-bridge circuits 672 and 673, which are the "second circuits". Although the duty ratio has been described, it mainly refers to the voltage applied between the lines of the actuator, and the duty ratio of each bridge arm is determined according to the voltage to be applied. When a part of the bridge arms is shared between the H-bridge circuits 672 and 673 and the three-phase inverter circuit 68, the increase and decrease of the duty ratio can also be achieved by only using the shared bridge arms.

[0136] The control unit 30 includes a mediation processing unit 35 and a duty ratio command unit 36 as modules for controlling the drive of the lock actuator 710. A steering lock operation command is input to the mediation processing unit 35. The mediation processing unit 35 performs mediation so that the lock actuator 710 operates when steering lock is prioritized, and the lock actuator 710 does not operate when steering lock is not prioritized.

[0137] When the lock actuator 710 is to be operated, the duty ratio command unit 36 sets the time profile of the duty ratio command. Although the duty ratio can be increased immediately, it is more preferable to set the duty ratio to increase from 0 to a specified value, maintain it for a specified time, and then return to 0. Also, according to the forward / backward rotation direction of the actuator, the duty ratio can be set to decrease from 100 to a specified value, maintain it for a specified time, and then return to 100. A drive signal based on this duty ratio is output to the H-bridge circuit 671, which is the "third circuit". Although the duty ratio has been described, it mainly refers to the voltage applied between the lines of the actuator, and the duty ratio of each bridge arm is determined according to the voltage to be applied. When a part of the bridge arms is shared between the H-bridge circuit 671 and the three-phase inverter circuit 68, the increase and decrease of the duty ratio can also be achieved by only using the shared bridge arms.

[0138] As an example of the actions corresponding to the priorities, the steering assist actuator 800 restricts the current command, the position system actuators 720, 730 change the duty ratio, and it is determined whether the locking actuator 710 operates. However, the method of restriction can be changed. For example, the mediation processing unit 39 that mediates the total duty ratio to each actuator may restrict only the duty ratio in all three cases. In this case, in the structure where the H-bridge circuits 671, 672, 673 and the three-phase inverter circuit 68 share a part of the bridge arm, the restriction process of the total value of the applied voltage applied to the steering assist actuator 800 and the DC motors 710, 720, 730 becomes easy. In contrast, in the case of restricting the current command of the illustrated steering assist actuator 800, it is easy to ensure the minimum output torque of the steering assist actuator 800. In addition, the process can be simplified by simply stopping other structures when the priority structure is operating.

[0139] (Effect)

[0140] (1) In the ECU 10 of the first embodiment, the circuits 68, 672, 673 that drive the plurality of actuators 800, 720, 730 are provided within the same housing 600. The control unit 30 efficiently drives the plurality of actuators 800, 720, 730 by operating the "first circuit" 68 and the "second circuits" 672, 673 according to the priority of the operation sequence, output distribution, or output magnitude. Thereby, concentration of heat and power can be avoided, and the thermal mass and heat dissipation of the circuit can be suppressed. Therefore, the housing 600 can be miniaturized.

[0141] (2) The control unit 30 changes the priority according to the position of the steering device during the startup period. Specifically, when the steering device is in a position that cannot be reached by the driver's hand during the startup period, it is preferable to perform the tilting and telescoping operation that moves the position of the steering device. By moving the steering device to the memorized position, the driver can perform steering operation.

[0142] (3) In Figure 7 the circuit structure example 1 shown, the three-phase inverter circuit 68 and each H-bridge circuit 672, 673 are independently and parallely provided. Therefore, it is easy to prevent the influence on another drive circuit in the case where one drive circuit is abnormal.

[0143] (4) In Figure 8 , Figure 9 the circuit structure examples 2 and 3 shown, the three-phase inverter circuit 68 and the H-bridge circuits 672, 673 form the integrated power conversion circuits 650, 660, and the control unit 30 operates the integrated power conversion circuits 650, 660 comprehensively. The number of switching elements can be reduced by the integrated power conversion circuits 650, 660, and the housing 600 can be miniaturized.

[0144] (5) In Figure 9 In the circuit configuration example 3 shown, the three-phase motor constituting the steering assist actuator 800 is a dual-winding rotating electric machine having two sets of three-phase windings 801, 802. The "first circuit" 68 is composed of two three-phase inverter circuits 681, 682. By making the steering assist actuator 800 a redundant structure, the reliability is improved.

[0145] (6) The control unit 30 of circuit configuration examples 2 and 3 limits the total value of the applied voltages applied to the steering assist actuator 800 and the position system actuators 720, 730 to less than a specified value according to the priority. Thereby, the maximum voltage can be effectively used, which is effective for miniaturization of the device.

[0146] (Other embodiments)

[0147] (a) When the steering assist actuator 800 is composed of a multi-phase rotating electric machine, it is not limited to a three-phase motor, and may be composed of a motor with four or more phases. In addition, the steering assist actuator 800 is not limited to a multi-phase motor such as a three-phase motor, and may be composed of a DC motor or an actuator other than a motor.

[0148] (b) The position system actuators 720, 730, and the locking actuator 710 are not limited to DC motors, and may be composed of actuators other than motors such as linear cylinders.

[0149] (c) The position system actuators 720, 730 are not limited to the two tilt actuators 720 and the telescopic actuator 730. As long as the position of the steering device is moved by one or more actuators (such as a DC motor). Correspondingly, the number of the second circuits (such as H-bridge circuits) is not limited to two, as long as it is one or more. When there is one "DC rotating electric machine" and one "H-bridge circuit", the "each" in "each DC rotating electric machine" and "each H-bridge circuit" is not premised on a plurality, but is interpreted as a prefix meaning "one of them".

[0150] (d) It is also possible to Figures 7 to 9 add a three-phase motor relay, a DC motor relay to the circuit configuration example shown, or add an LC filter circuit to the input section. They can be added to the first circuit, the second circuit, and the third circuit respectively, or shared. In addition, the first circuit and the second circuit may be connected to separate power supplies instead of being connected to the common power supply Bt.

[0151] The present disclosure is not limited to such embodiments, and can be implemented in various forms without departing from its gist.

[0152] The control unit and method described in the present disclosure can also be implemented by a dedicated computer provided by a processor and a memory configured to execute one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure can also be implemented by a dedicated computer provided by using a processor constituted by one or more dedicated hardware logic circuits. Alternatively, the control unit and method described in the present disclosure can also be implemented by one or more dedicated computers constituted by a combination of a processor configured to execute one or more functions and a memory and a processor constituted by one or more hardware logic circuits. In addition, the computer program can also be stored as instructions executed by a computer in a computer-readable non-transitory tangible recording medium.

[0153] The present disclosure has been described based on embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent scope. In addition, various combinations and modes, and further combinations and modes including only one element, one or more or less than one of them are also included in the scope and spirit of the present disclosure.

Claims

1. A steering control device, comprising: A first circuit that energizes a steering assist actuator for electrically assisting a driver's steering operation; One or more second circuits, disposed in the same housing as the first circuit, that energize one or more position system actuators for moving the position of the steering device; and A control unit that operates the first circuit and the second circuit to control the operations of the steering assist actuator and the position system actuator, The above control unit changes priorities during multiple periods including a startup period, a normal operation period, and a stop period, where, The startup period is the period during which the steering control device starts up, the normal operation period is the period during which the steering control device performs normal operations, the stop period is the period during which the steering control device stops, and the priority is any one or more of the order in which the first circuit and the second circuit operate, the distribution of the outputs of the first circuit and the second circuit, or the magnitude of the outputs.

2. The steering control device according to claim 1, wherein The steering assist actuator is a polyphase rotating electric machine having one or more sets of polyphase windings, The position system actuator is a DC rotating electric machine, The first circuit is composed of one or more polyphase inverter circuits, wherein the polyphase inverter circuit converts DC power and energizes the steering assist actuator, The second circuit is composed of an H-bridge circuit, and the H-bridge circuit converts DC power and energizes the position system actuator, If a set of high-potential side and low-potential side switching elements connected in series in the polyphase inverter circuit and the H-bridge circuit is regarded as a bridge arm, then One end, i.e., the first terminal, of each of the DC rotating electric machines is connected to the phase current path of one phase of the polyphase winding, and the other end, i.e., the second terminal, is connected to a switching element for the DC rotating electric machine forming one side of the bridge arm of each of the H-bridge circuits, At least one of the polyphase inverter circuits and each of the H-bridge circuits form an integrated power conversion circuit that shares a bridge arm of one phase of the polyphase inverter circuit and one side of the bridge arm of each of the H-bridge circuits.

3. The steering control device according to claim 1, wherein The steering assist actuator is a polyphase rotating electric machine having one or more sets of polyphase windings, The position system actuator is one or more DC rotating electric machines, The above-mentioned first circuit is composed of more than one polyphase inverter circuit, where, The polyphase inverter circuit converts DC power and energizes the steering assist actuator, The second circuit is composed of an H-bridge circuit, and the H-bridge circuit converts DC power and energizes the position system actuator, The polyphase inverter circuit and each of the H-bridge circuits are independently and parallelly provided.

4. The steering control device according to claim 2, wherein The polyphase rotating electric machine is a dual-winding rotating electric machine having two sets of polyphase windings, The first circuit is composed of two polyphase inverter circuits, and the polyphase inverter circuits energize the two sets of polyphase windings, Each of the DC rotating electric machines is connected to the phase current path of one of the two sets of polyphase windings.

5. The steering control device according to claim 2 or 4, wherein The control unit restricts the total value of the applied voltages applied to the steering assist actuator and the position system actuator to be less than a specified value according to the priority.

6. The steering control device according to claim 2 or 4, wherein, There are a plurality of the above-mentioned position system actuators, and when current flows from the above-mentioned first terminal toward the above-mentioned second terminal, the plurality of the above-mentioned position system actuators act in the same direction relative to the driver.

7. The steering control device according to any one of claims 1 to 4, wherein, A third circuit is provided, and the third circuit energizes a locking actuator, and the locking actuator drives a locking device that mechanically restricts the rotation of the steering device.

8. The steering control device according to any one of claims 1 to 4, wherein, The control circuit changes the above-mentioned priority according to the position of the steering device during the above-mentioned start-up period.

Images