JP2015030402A - Control device of hydraulic power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a hydraulic power steering device which can prevent the lowering of a steering feeling even if an abnormality is detected in one electric pump.SOLUTION: A control device of a hydraulic steering device comprises: steering angle detection means which detects a steering angle of a steering wheel; steering speed calculation means which calculates a steering speed from the steering angle which is detected by the steering angle detection means; and control means which controls the operation of a hydraulic actuator by the supply of drive power to a three-phase brushless motor. When the steering speed calculated by the steering speed calculation means reaches a prescribed value or higher in the case that one phase of the three-phase brushless motor of one electric pump becomes abnormal due to an energization failure during a first and second electric pumps are in operation, the control means operates the three-phase brushless motor for driving the electric pump whose one phase is stopped due to the energization failure by two-phase drive.

Description

  The present invention relates to a control device for a hydraulic power steering device.

  2. Description of the Related Art Conventionally, a hydraulic power steering device that applies an assist force to a steering system using a hydraulic actuator such as a hydraulic cylinder is widely known. For example, Patent Document 1 discloses a hydraulic power steering apparatus using two electric pumps that generate hydraulic pressure by driving two motors as a hydraulic source of a hydraulic actuator. In such a hydraulic power steering device, even when the steering operation is not performed, the electric pump is driven at a relatively low rotational speed (standby rotational speed), so that a quick assist force can be quickly applied. The improvement of the nature is aimed at.

JP 09-095251 A JP 2008-2111910 A

  By the way, in such a hydraulic power steering apparatus using two electric pumps that generate hydraulic pressure by driving two motors, when one of the electric pumps detects an abnormality, the electric pump is immediately stopped. It was. Therefore, when the steering is steered suddenly, there is a problem that a feeling of catching occurs and the steering feeling is uncomfortable.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to control a hydraulic power steering apparatus that can prevent a decrease in steering feeling even when one of the electric pumps detects an abnormality. Is to provide.

  A control device for a hydraulic power steering apparatus that solves the above-described problems is a first for supplying hydraulic oil to a hydraulic actuator that generates an assist force for assisting a steering operation in a steering system using a three-phase brushless motor as a drive source. And a control apparatus for a hydraulic power steering apparatus including the second electric pump, a steering angle detecting means for detecting a steering angle of the steering, and a steering speed for calculating a steering speed from the steering angle detected by the steering angle detecting means. An arithmetic means, a control means for controlling the operation of the hydraulic actuator through supply of driving power to the three-phase brushless motor, and the control means are configured to operate one of the electric actuators while the first and second electric pumps are in operation. When one phase of the three-phase brushless motor for driving the pump becomes abnormal due to poor energization, the steering speed When the steering speed calculated from the calculation means is equal to or greater than a predetermined value, actuating one phase of the three-phase brushless motor for driving the electric pump is stopped poor energized the two-phase drive, and the gist.

  According to the above configuration, when one phase of the three-phase brushless motor for driving one of the electric pumps becomes abnormal due to poor conduction while the first and second electric pumps are operating, the steering speed is equal to or higher than a predetermined value. In this case, the configuration is such that the three-phase brushless motor for driving the electric pump whose one phase is stopped due to poor energization is operated by two-phase driving. As a result, when the steering is steered at a high speed, the assist force increases, so that the steering feeling can be prevented and the steering feeling can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, even when one electric pump detects abnormality, the control apparatus of the hydraulic power steering device which can prevent the fall of steering feeling can be provided.

The schematic block diagram of a hydraulic power steering device. 1 is a schematic control block diagram of a hydraulic power steering device. The detailed control block diagram of a 1st microcomputer. The detailed control block diagram of a 2nd microcomputer. The flowchart which shows the control procedure of the 1st and 2nd electric pump in case the 1st or 2nd electric pump changes from a normal operation state to an abnormal operation state. The map figure in the target speed command value calculating part of a 1st and 2nd microcomputer.

Hereinafter, embodiments of a hydraulic power steering apparatus will be described with reference to the drawings.
A hydraulic power steering apparatus 1 shown in FIG. 1 is mounted on a vehicle having an idle stop function for automatically stopping an engine at a temporary stop. As shown in the figure, a hydraulic power steering apparatus 1 includes a steering shaft 3 to which a steering wheel 2 is fixed, a rack shaft 5 that reciprocates in the axial direction according to the rotation of the steering shaft 3, and a rack shaft 5 And a substantially cylindrical rack housing 6 which is inserted so as to be reciprocally movable. The steering shaft 3 is configured by connecting a column shaft 7, an intermediate shaft 8, and a pinion shaft 9 in this order from the steering wheel 2 side.

The rack shaft 5 and the pinion shaft 9 are arranged in the rack housing 6 with a predetermined crossing angle, and the rack teeth 5a formed on the rack shaft 5 and the pinion teeth 9a formed on the pinion shaft 9 are meshed with each other. Thus, the rack and pinion mechanism 11 is configured.
Further, tie rods 12 are connected to both ends of the rack shaft 5, and the tip of the tie rod 12 is connected to a knuckle (not shown) to which the steered wheels 13 are assembled. Therefore, in the hydraulic power steering apparatus 1, the rotation of the steering shaft 3 accompanying the steering operation is converted into the axial movement of the rack shaft 5 by the rack and pinion mechanism 11, and this axial movement is transmitted to the knuckle through the tie rod 12. Thus, the turning angle of the steered wheels 13, that is, the traveling direction of the vehicle is changed.

  The hydraulic power steering apparatus 1 also includes a hydraulic cylinder 21 as a hydraulic actuator that generates an assist force that assists the steering operation, and first and second electric pumps 22 and 23 that supply hydraulic oil to the hydraulic cylinder 21. ing. In addition, the hydraulic power steering device 1 stores hydraulic oil supplied to and discharged from the hydraulic cylinder 21 by the switching valve 24 that controls supply and discharge of hydraulic oil to the hydraulic cylinder 21 and the first and second electric pumps 22 and 23. The storage tank 25 is provided.

  The hydraulic cylinder 21 includes a cylindrical cylinder tube 31 constituted by a part of the rack housing 6. That is, the rack shaft 5 is inserted into the cylinder tube 31 so as to be able to reciprocate. The hydraulic cylinder 21 includes a piston 34 that divides the cylinder tube 31 into a first hydraulic chamber 32 and a second hydraulic chamber 33, and the piston 34 is fixed to the rack shaft 5 so as to be movable in the axial direction. Has been.

  As shown in FIG. 2, the first electric pump 22 includes a first motor 41 as a driving source, a first pump 42 that generates hydraulic pressure by being driven by the first motor 41, and an operation of the first motor 41. And a first ECU 43 for controlling the control. The second electric pump 23 includes a second motor 44 serving as a drive source, a second pump 45 that generates hydraulic pressure when driven by the second motor 44, and a second ECU 46 that controls the operation of the second motor 44. And. That is, in the present embodiment, the first and second ECUs 43 and 46 constitute a control device. As shown in FIG. 1, each suction port (not shown) of the first and second electric pumps 22 and 23 is connected to the storage tank 25 via a suction oil passage 47.

  The switching valve 24 is configured as a known rotary valve that controls supply and discharge of hydraulic oil to and from the first and second hydraulic chambers 32 and 33 of the hydraulic cylinder 21 in conjunction with the steering operation. Specifically, the switching valve 24 is provided with a supply port 51, a discharge port 52, and first and second supply / discharge ports 53 and 54. The supply port 51 is connected to the discharge ports (not shown) of the first and second electric pumps 22 and 23 via a supply oil passage 55 that branches into two branches on one end side. The discharge port 52 is connected to the storage tank 25 through a discharge oil passage 56. The first supply / discharge port 53 is connected to the first hydraulic chamber 32 via the first supply / discharge oil passage 57, and the second supply / discharge port 54 is connected to the first oil supply / discharge passage 58 via the second supply / discharge oil passage 58. 2 It is connected to the hydraulic chamber 33.

  In the hydraulic power steering apparatus 1 configured as described above, the hydraulic oil sucked up from the storage tank 25 by the first and second electric pumps 22 and 23 is supplied to the switching valve 24 via the supply oil passage 55. . Then, the hydraulic oil supplied to the switching valve 24 passes through one of the first and second oil supply / discharge passages 57 and 58 according to the driver's steering operation, and the first and second hydraulic chambers 32. , 33 is supplied. At this time, the hydraulic oil is discharged from the other one of the first and second hydraulic chambers 32 and 33, and this hydraulic oil is the other of the first and second supply / discharge oil passages 57 and 58, the switching valve 24 and the discharge oil passage. It is discharged to the storage tank 25 through 56. As a result, a hydraulic pressure difference is generated between the first hydraulic chamber 32 and the second hydraulic chamber 33, and the steering operation is assisted by the rack shaft 5 moving in the axial direction together with the piston 34 based on this hydraulic pressure difference. The

Next, the electrical configuration of the hydraulic power steering apparatus 1 will be described.
As shown in FIGS. 1 and 2, the first and second electric pumps 22 and 23 are connected to each other via a CAN (in-vehicle network) 61. A steering sensor 62 and a vehicle speed sensor 63 are connected to the CAN 61, respectively, and a steering angle θs (steering angle detection means) and a vehicle speed v of the steering wheel 2 are transmitted. Further, the upper ECU 64 is connected to the CAN 61, and the first and second ECUs 43 and 46 cooperate with each other based on the respective state quantities obtained via the CAN 61, and the first and second electric pumps 22 and 23. The operation of the (first and second motors 41 and 44) can be controlled.

  Signals transmitted to and received from the first ECU 43 via the host ECU 64 and the CAN 61 are the steering angle θs, the vehicle speed v, the first electric pump abnormality determination signal Sf1, the first electric pump one-phase conduction failure signal Sf11, and the first electric pump normal control command. COM10, first electric pump two-phase drive command COM11, and first electric pump stop command COM12. Similarly, signals transmitted / received to / from the second ECU 46 via the host ECU 64 and the CAN 61 are the steering angle θs, the vehicle speed v, the second electric pump abnormality determination signal Sf2, the second electric pump one-phase conduction failure signal Sf22, and the second electric pump normal. The control command COM20, the second electric pump two-phase drive command COM21, and the second electric pump stop command COM22.

  The first ECU 43 and the second ECU 46 will be described in detail. As shown in FIG. 2, the first ECU 43 is driven by the first microcomputer 41 (control means) that outputs a motor control signal and the first motor 41 based on the motor control signal. And a first drive circuit 72 for supplying electric power. The second ECU 46 includes a second microcomputer 73 (control means) that outputs a motor control signal, and a second drive circuit 74 that supplies drive power to the second motor 44 based on the motor control signal. The first and second drive circuits 72 and 74 are connected to the same in-vehicle power source (battery) 75 mounted on the vehicle, respectively.

  The first and second drive circuits 72 and 74 include a known PWM inverter in which a pair of switching elements (for example, FETs) connected in series is a basic unit (switching arm) and these are connected in parallel. The motor control signal is used to define the on / off state (on-duty ratio) of each switching element. Then, the first and second drive circuits 72 and 74 supply drive power based on the on-duty ratio and the voltage of the in-vehicle power supply 75 indicated by the input motor control signal to the first and second motors 41 and 44, respectively. .

  The first microcomputer 71 detects a U-phase actual current value Iu1, a V-phase actual current value Iv1, and a W-phase actual current value Iw1 flowing through the first motor 41 (first electric pump 22). , 76v, 76w, and a first rotation angle sensor 77 for detecting a first rotation angle θ1 indicating the rotation angle of the first motor 41 is connected. On the other hand, the second microcomputer 73 detects a U-phase actual current value Iu2, a V-phase actual current value Iv2, and a W-phase actual current value Iw2 flowing through the second motor 44 (second electric pump 23). A sensor 78u, 78v, 78w and a second rotation angle sensor 79 for detecting a second rotation angle θ2 indicating the rotation angle of the second motor 44 are connected.

  The first and second microcomputers 71 and 73 detect each state quantity from each sensor at a predetermined sampling period, and receive each state quantity from the CAN 61. Then, the first and second microcomputers 71 and 73 control the operation of the first and second motors 41 and 44 through the supply of driving power by outputting a motor control signal based on the acquired state quantities. .

  Each control block shown below is realized by a computer program executed by the first and second microcomputers 71 and 73. The first and second microcomputers 71 and 73 generate the motor control signal by detecting each state quantity at a predetermined sampling period and executing each arithmetic processing shown in the following control blocks at each predetermined period. To do.

Next, details of the function of the first microcomputer 71 will be described in detail with reference to FIG.
First, the first microcomputer 71 takes in the steering angle θs, the vehicle speed v, the first electric pump normal control command COM10, the first electric pump two-phase drive command COM11, and the first electric pump stop command COM12 transmitted from the CAN 61. Then, the first microcomputer 71 transmits the first electric pump abnormality determination signal Sf1 and the first electric pump one-phase conduction failure signal Sf11 from the CAN 61 to the host ECU 64.

  Next, the first microcomputer 71 differentiates the steering angle θs with the differentiator 101 (steering speed calculation means) to calculate the steering speed ωs. Subsequently, the first microcomputer 71 takes the steering speed ωs and the vehicle speed v into the first target speed command calculation unit 80. In the first target speed command calculation unit 80, a first map 81 for generating a first target speed command value ω1 * is composed of a steering speed ωs and a vehicle speed v. Here, as an example, the first map 81 is configured as shown in FIG. 6 (described later) from experimental values and the like.

  Next, the first microcomputer 71 inputs the first target speed command value ω <b> 1 * generated by the first target speed command calculation unit 80 to the subtractor 97. Further, the first microcomputer 71 differentiates the first rotation angle θ1 output from the first rotation angle sensor 77 of the first motor 41 by the differentiator 96 to generate the first rotation speed ω1. Then, the first microcomputer 71 inputs the first rotation speed ω <b> 1 generated by the differentiator 96 to the subtractor 97. Then, the first microcomputer 71 subtracts the first rotational speed ω1 from the first target speed command value ω1 * by the subtractor 97 to generate the first speed deviation Δω1.

  Next, the first microcomputer 71 inputs the generated first speed deviation Δω1 to the proportional and integral control unit 82 of the first speed control. The first microcomputer 71 is a proportional and integral control unit 82 of the first speed control. From the product of the first speed deviation Δω1, the proportional gain of the first speed control, and the integral gain of the first speed control, A first q-axis current command value Iq1 * is generated. Then, the first microcomputer 71 inputs the generated first q-axis current command value Iq1 * to the subtractor 98. Then, the first microcomputer 71 uses the subtractor 98 to subtract the first q-axis current value Iq1 from the first q-axis current command value Iq1 * to generate a first q-axis current deviation ΔIq1.

Here, a method of generating the first q-axis current value Iq1 and the first d-axis current value Id1 will be described.
First, the first microcomputer 71 takes in the U-phase actual current value Iu1, the V-phase actual current value Iv1, and the W-phase actual current value Iw1 of the first electric pump 22 detected by the first current sensors 76u, 76v, and 76w. . Then, the first microcomputer 71 converts the captured U-phase actual current value Iu1, V-phase actual current value Iv1, and W-phase actual current value Iw1 into a first q-axis that is a two-phase current in the first d / q conversion calculation unit 91. A current value Iq1 and a first d-axis current value Id1 are generated.

  Next, the first microcomputer 71 inputs the generated first q-axis current deviation ΔIq1 to the proportional and integral control unit 85 of the first q-axis current control. Then, the first microcomputer 71 is a proportional / integral control unit 85 of the first q-axis current control, and a product of the first q-axis current deviation ΔIq1 and the proportional gain of the first q-axis current control and the integral gain of the first q-axis current control. The first q-axis voltage command value Vq1 * is generated and input to the first d / q inverse transformation calculation unit 92.

  On the other hand, the first microcomputer 71 sets the first d-axis current command value Id1 * to zero and inputs it to the subtractor 99. The first microcomputer 71 then subtracts the first d-axis current value Id1 from the first d-axis current command value Id1 * by the subtractor 99 to generate a first d-axis current deviation ΔId1.

  Next, the first microcomputer 71 inputs the generated first d-axis current deviation ΔId1 to the proportional and integral control unit 88 of the first d-axis current control. Then, the first microcomputer 71 is a proportional and integral control unit 88 for the first d-axis current control, and a product of the first d-axis current deviation ΔId1 and the proportional gain for the first d-axis current control and the integral gain for the first d-axis current control. The first d-axis voltage command value Vd1 * is generated and input to the first d / q inverse transformation calculation unit 92.

  Next, the first microcomputer 71 determines the first phase voltage command value Vu1 * from the first q-axis voltage command value Vq1 * and the first d-axis voltage command value Vd1 * input to the first d / q inverse conversion calculation unit 92. , Vv1 *, Vw1 * are generated and input to the first PWM output unit 93. Then, the first microcomputer 71 outputs a motor control signal from the first PWM output unit 93 to the first drive circuit 72.

  Further, the first microcomputer 71 is based on the U-phase actual current value Iu1, the V-phase actual current value Iv1, the W-phase actual current value Iw1, the first rotation angle θ1, and the first rotation speed ω1 of the first electric pump 22. And a first abnormality determination unit 94 that determines abnormality of the first motor 41. Then, the first microcomputer 71 transmits the first electric pump abnormality determination signal Sf1 determined by the first abnormality determination unit 94 and the first electric pump one-phase conduction failure signal Sf11 to the CAN 61. Then, when the first electric pump abnormality is detected, the first microcomputer 71 stops the supply of drive power and stops the first motor 41.

  On the other hand, the first microcomputer 71 operates the first motor 41 by two-phase drive control (described later) when the first electric pump one-phase energization failure is detected. In addition, as a method of abnormality determination, for example, when the U-phase actual current value Iu1, the V-phase actual current value Iv1, and the W-phase actual current value Iw1 of the first electric pump 22 become values that cannot be taken, It is possible to adopt various methods such as determining that there is an abnormality when the first rotation angle θ1 or the first rotation speed ω1 does not change in spite of the supply.

  Further, the first microcomputer 71 controls the first microcomputer two-phase drive control unit 95 to perform the two-phase drive control of the first motor 41 when the first abnormality determination unit 94 detects the first electric pump one-phase conduction failure. have. The first electric pump two-phase drive command COM11 input from the host ECU 64 to the first abnormality determination unit 94 of the first microcomputer 71 is routed to the first microcomputer two-phase drive control via the first target speed command calculation unit 80. Is output to the unit 95.

  The first microcomputer two-phase drive control unit 95 executes the two-phase drive calculation, and then outputs the first phase voltage command values Vu1 **, Vv1 **, and Vw1 ** to the first PWM output unit 93 during the two-phase drive control. input. Then, the first microcomputer 71 outputs a motor control signal from the first PWM output unit 93 to the first drive circuit 72. Refer to Patent Document 2 for details of the two-phase drive control.

Next, details of the function of the second microcomputer 73 will be described in detail with reference to FIG.
The function of the second microcomputer 73 is almost the same as the function of the first microcomputer 71.
First, the second microcomputer 73 takes in the steering angle θs, the vehicle speed v, the second electric pump normal control command COM20, the second electric pump two-phase drive command COM21, and the second electric pump stop command COM22 transmitted from the CAN 61. Then, the second microcomputer 73 transmits the second electric pump abnormality determination signal Sf2 and the second electric pump one-phase conduction failure signal Sf22 from the CAN 61 to the host ECU 64.

  Next, the second microcomputer 73 differentiates the steering angle θs with a differentiator 131 (steering speed calculating means) to calculate the steering speed ωs. Subsequently, the second microcomputer 73 takes the steering speed ωs and the vehicle speed v into the second target speed command calculation unit 110. In the second target speed command calculation unit 110, a second map 111 for generating the second target speed command value ω2 * is configured from the steering speed ωs and the vehicle speed v. Here, as an example, the second map 111 is configured as shown in FIG. 6 (described later) from experimental values and the like.

  Next, the second microcomputer 73 inputs the second target speed command value ω <b> 2 * generated by the second target speed command calculation unit 110 to the subtractor 127. Further, the second microcomputer 73 differentiates the second rotation angle θ2 output from the second rotation angle sensor 79 of the second motor 44 by the differentiator 126 to generate a second rotation speed ω2. Then, the second microcomputer 73 inputs the second rotational speed ω <b> 2 generated by the differentiator 126 to the subtractor 127. Then, the second microcomputer 73 uses the subtractor 127 to subtract the second rotational speed ω2 from the second target speed command value ω2 * to generate a second speed deviation Δω2.

  Next, the second microcomputer 73 inputs the generated second speed deviation Δω2 to the proportional and integral control unit 112 of the second speed control. Then, the second microcomputer 73 adds the product of the second speed deviation Δω2, the proportional gain of the second speed control, and the product of the integral gain of the second speed control in the proportional and integral control unit 112 of the second speed control. As a result, the second q-axis current command value Iq2 * is generated. Then, the second microcomputer 73 inputs the generated second q-axis current command value Iq2 * to the subtracter 128. Then, the second microcomputer 73 subtracts the second q-axis current value Iq2 from the second q-axis current command value Iq2 * by the subtractor 128 to generate a second q-axis current deviation ΔIq2.

Here, a method of generating the second q-axis current value Iq2 and the second d-axis current value Id2 will be described.
First, the second microcomputer 73 takes in the U-phase actual current value Iu2, the V-phase actual current value Iv2, and the W-phase actual current value Iw2 of the second electric pump 23 detected by the second current sensors 78u, 78v, and 78w. . Then, the second microcomputer 73 converts the captured U-phase actual current value Iu2, V-phase actual current value Iv2, and W-phase actual current value Iw2 into a second q-axis that is a two-phase current in the second d / q conversion calculation unit 121. A current value Iq2 and a second d-axis current value Id2 are generated.

  Next, the second microcomputer 73 inputs the generated second q-axis current deviation ΔIq2 to the proportional and integral control unit 115 of the second q-axis current control. The second microcomputer 73 is a proportional / integral control unit 115 for the second q-axis current control, and the product of the second q-axis current deviation ΔIq2 and the proportional gain for the second q-axis current control, and the integral gain for the second q-axis current control. The second q-axis voltage command value Vq2 * is generated and input to the second d / q inverse transformation calculation unit 122.

  On the other hand, the second microcomputer 73 sets the second d-axis current command value Id2 * to zero and inputs it to the subtractor 129. Then, the second microcomputer 73 subtracts the second d-axis current value Id2 from the second d-axis current command value Id2 * by the subtractor 129 to generate a second d-axis current deviation ΔId2.

  Next, the second microcomputer 73 inputs the generated second d-axis current deviation ΔId2 to the proportional and integral control unit 118 of the second d-axis current control. Then, the second microcomputer 73 is a proportional and integral control unit 118 for the second d-axis current control, and the product of the second d-axis current deviation ΔId2 and the proportional gain for the second d-axis current control and the integral gain for the second d-axis current control. Are added to generate a second d-axis voltage command value Vd2 *, which is input to the second d / q inverse transformation calculation unit 122.

  Next, the second microcomputer 73 calculates the second phase voltage command value Vu2 * from the second q-axis voltage command value Vq2 * and the second d-axis voltage command value Vd2 * input to the second d / q inverse conversion calculation unit 122. , Vv2 *, Vw2 * are generated and input to the second PWM output unit 123. Then, the second microcomputer 73 outputs a motor control signal from the second PWM output unit 123 to the second drive circuit 74.

  Similarly to the first microcomputer 71, the second microcomputer 73 has a U-phase actual current value Iu2, a V-phase actual current value Iv2, a W-phase actual current value Iw2, a second rotation angle θ2, And a second abnormality determination unit 124 that determines abnormality of the second motor 44 based on the second rotational speed ω2. Then, the second microcomputer 73 transmits the second electric pump abnormality determination signal Sf2 and the second electric pump one-phase conduction failure signal Sf22 determined by the second abnormality determination unit 124 to the CAN 61.

  Then, when the second electric pump abnormality is detected, the second microcomputer 73 stops the supply of drive power and stops the second motor 44. On the other hand, the second microcomputer 73 operates the second motor 44 by the two-phase drive control when the second electric pump one-phase energization failure is detected. In addition, as a method of abnormality determination, for example, when the U-phase actual current value Iu2, the V-phase actual current value Iv2, and the W-phase actual current value Iw2 of the second electric pump 23 become values that cannot be taken, It is possible to adopt various methods such as determining that there is an abnormality when the second rotation angle θ2 or the second rotation speed ω2 does not change in spite of the supply.

  Furthermore, the second microcomputer 73 causes the second microcomputer two-phase drive control unit 125 to control the second motor 44 to two-phase drive when the second abnormality determination unit 124 detects a second electric pump one-phase conduction failure. have. The second electric pump two-phase drive command COM21 input from the host ECU 64 to the second abnormality determination unit 124 of the second microcomputer 73 is routed to the second microcomputer two-phase drive control via the second target speed command calculation unit 110. Is output to the unit 125. The second microcomputer two-phase drive control unit 125 executes the two-phase drive calculation, and then outputs the second phase voltage command values Vu2 **, Vv2 **, and Vw2 ** to the second PWM output unit 123 during the two-phase drive control. input. Then, the second microcomputer 73 outputs a motor control signal from the second PWM output unit 123 to the second drive circuit 74. Refer to Patent Document 2 for details of the two-phase drive control.

  The above describes the function when the host ECU 64 outputs a rotation command to the first and second electric pumps 22 and 23 simultaneously. However, in the present embodiment, after the first and second electric pumps 22 and 23 are operating, one phase of the three-phase brushless motor for driving of the first or second electric pump is stopped due to poor energization, and then steering is performed. When the steering speed is more than a predetermined value (emergency steering), the three-phase brushless motor for driving the electric pump, which has stopped due to poor conduction in one phase, is operated by two-phase driving, thereby improving the steering feeling. Prevent decline.

The control procedure of the first and second electric pumps 22 and 23 when the first or second electric pump changes from the normal operation state to the abnormal operation state will be described in detail with reference to FIG.
First, the ECU 64 determines whether or not the steering speed ωs is equal to or higher than a predetermined steering speed ωs0 (step S101). When the steering speed ωs is equal to or higher than the predetermined steering speed ωs0 (step S101: YES), the ECU 64 next determines whether or not the first electric pump 22 is normal (step S102). When the first electric pump 22 is normal (step S102: YES), the ECU 64 continues to determine whether the second electric pump 23 is normal (step S103).

  Then, when the second electric pump 23 is normal (step S103: YES), the ECU 64 transmits the first electric pump normal control command COM10 to the first microcomputer 71 via the CAN 61. The first microcomputer 71 receives the first electric pump normal control command COM10 and performs the first electric pump normal control (step S104). Further, the ECU 64 transmits the second electric pump normal control command COM20 to the second microcomputer 73 via the CAN 61. The second microcomputer 73 receives the second electric pump normal control command COM20, performs the second electric pump normal control (step S105), and ends the process.

  On the other hand, when the second electric pump 23 is not normal (step S103: NO), the ECU 64 determines whether or not it is a one-phase conduction failure based on the second electric pump one-phase conduction failure signal Sf22 (step S103). S106). When the ECU 64 determines that the second electric pump has a one-phase conduction failure (step S106: YES), the ECU 64 transmits the first electric pump normal control command COM10 to the first microcomputer 71 via the CAN 61. .

  Next, the first microcomputer 71 receives the first electric pump normal control command COM10 and performs the first electric pump normal control (step S107). Further, the ECU 64 transmits the second electric pump two-phase drive command COM21 to the second microcomputer 73 via the CAN 61. The second microcomputer 73 receives the second electric pump two-phase drive command COM21, performs the second electric pump two-phase drive control (step S108), and ends the process.

  Further, when the ECU 64 determines that the second electric pump is in an abnormality that is not a one-phase conduction failure (step S106: NO), the ECU 64 sends a first electric pump normal control command COM10 to the first microcomputer 71 via the CAN 61. Send. The first microcomputer 71 receives the first electric pump normal control command COM10 and performs the first electric pump normal control (step S109). In addition, the ECU 64 transmits the second electric pump stop command COM22 to the second microcomputer 73 via the CAN 61. The second microcomputer 73 receives the second electric pump stop command COM22, stops the second electric pump (step S110), and ends the process.

  Next, when the first electric pump 22 is not normal (step S102: NO), the ECU 64 continues to determine whether the first electric pump one-phase conduction failure signal Sf11 is a one-phase conduction failure. Determination is made (step S111). If the ECU 64 determines that the first electric pump 22 has a one-phase energization failure (step S111: YES), the ECU 64 subsequently determines whether or not the second electric pump 23 is normal ( Step S112). Then, if the second electric pump 23 is normal (step S112: YES), the ECU 64 transmits the first electric pump two-phase drive command COM11 to the first microcomputer 71 via the CAN 61.

  Then, the first microcomputer 71 receives the first electric pump two-phase drive command COM11 and performs the first electric pump two-phase drive control (step S113). Further, the ECU 64 transmits the second electric pump normal control command COM20 to the second microcomputer 73 via the CAN 61. The second microcomputer 73 receives the second electric pump normal control command COM20, performs the second electric pump normal control (step S114), and ends the process.

  Next, when the second electric pump 23 is not normal (step S112: NO), the ECU 64 transmits a first electric pump stop command COM12 to the first microcomputer 71 via the CAN 61. The first microcomputer 71 receives the first electric pump stop command COM12 and stops the first electric pump (step S115). In addition, the ECU 64 transmits the second electric pump stop command COM22 to the second microcomputer 73 via the CAN 61. The second microcomputer 73 receives the second electric pump stop command COM22, stops the second electric pump (step S116), and ends the process.

  Next, when the ECU 64 determines that the first electric pump 22 is not abnormal with one-phase conduction failure (step S111: NO), the ECU 64 subsequently determines whether or not the second electric pump 23 is normal. Determination is made (step S117). Then, when the second electric pump 23 is normal (step S117: YES), the ECU 64 transmits the first electric pump stop command COM12 to the first microcomputer 71 via the CAN 61. The first microcomputer 71 receives the first electric pump stop command COM12 and stops the first electric pump (step S118).

  Further, the ECU 64 transmits the second electric pump normal control command COM20 to the second microcomputer 73 via the CAN 61. The second microcomputer 73 receives the second electric pump normal control command COM20, performs the second electric pump normal control (step S119), and ends the process. Then, when the second electric pump 23 is not normal (step S117: NO), the ECU 64 proceeds to step S115.

  Next, when the steering speed ωs is smaller than the predetermined steering speed ωs0 (step S101: NO), the ECU 64 next determines whether or not the first electric pump 22 is normal (step S120). . Then, when the first electric pump 22 is normal (step S120: YES), the ECU 64 proceeds to step S109. Further, when the first electric pump 22 is not normal (step S120: NO), the ECU 64 continues to determine whether or not the second electric pump 23 is normal (step S121). Then, when the second electric pump 23 is normal (step S121: YES), the ECU 64 proceeds to step S118. Further, when the second electric pump 23 is not normal (step S121: NO), the ECU 64 proceeds to step S115.

Next, a map in the target speed command value calculation unit of the first and second microcomputers will be described with reference to FIG.
In FIG. 6, the horizontal axis represents the steering speed (deg / sec), the vertical axis represents the target rotational speed (rev / min), and the vehicle speed v.

  The target rotational speed ω * varies depending on the steering speed ωs and the vehicle speed v. In general, the lower the vehicle speed v, the larger the target rotational speed ω *. In this embodiment, the vehicle speed v is obtained from experimental values at 0 km / h, 40 km / h, 80 km / h, and 120 km / h, but interpolation may be performed during that time. In addition, the map figure of this embodiment changes with vehicle models, and may be adapted each time.

Next, the operation and effect of the control device for the hydraulic power steering apparatus of the present embodiment configured as described above will be described.
The steering angle detecting means for detecting the steering angle of the steering, the steering speed calculating means for calculating the steering speed from the steering angle detected by the steering angle detecting means, and the operation of the hydraulic actuator through the supply of driving power to the three-phase brushless motor. The control means for controlling the steering speed when the first and second electric pumps are operating, and one phase of the three-phase brushless motor for driving one of the electric pumps becomes abnormal due to poor conduction. When the steering speed calculated from the calculation means is equal to or higher than a predetermined value, the configuration is such that the three-phase brushless motor for driving the electric pump, which has stopped due to poor energization in one phase, is operated in two-phase driving.

  According to the above configuration, when one phase of the three-phase brushless motor for driving one of the electric pumps becomes abnormal due to poor conduction while the first and second electric pumps are operating, the steering speed is equal to or higher than a predetermined value. In this case, the three-phase brushless motor for driving the electric pump whose one phase is stopped due to a poor energization can be operated by two-phase driving. As a result, when the steering is steered at a high speed, the assist force increases, so that the steering feeling can be prevented and the steering feeling can be improved.

In addition, the said embodiment can also be implemented in the following aspects which changed this suitably.
In the present embodiment, the first and second electric pumps 22 and 23 are provided as the hydraulic pressure source of the hydraulic cylinder 21, but three or more electric pumps may be provided.

  In the present embodiment, the first and second electric pumps 22, 23 have the first and second ECUs 43, 46, respectively. However, the present invention is not limited to this, and the first and second motors 41, The operation of 44 may be controlled.

1: Hydraulic power steering device, 2: Steering wheel,
3: Steering shaft, 5: Rack shaft, 5a: Rack teeth,
6: rack housing, 7: column shaft, 8: intermediate shaft, 9: pinion shaft,
9a: Pinion teeth, 11: Rack and pinion mechanism, 12: Tie rod,
13: steered wheel, 21: hydraulic cylinder, 22: first electric pump, 23: second electric pump, 24: switching valve, 25: storage tank, 31: cylinder tube, 32: first hydraulic chamber,
33: second hydraulic chamber, 34: piston, 41: first motor, 42: first pump,
43: first ECU, 44: second motor, 45: second pump, 46: second ECU,
47: intake oil passage, 51: supply port, 52: discharge port, 53: first supply / discharge port,
54: second supply / discharge port, 55: supply oil passage, 56: discharge oil passage, 57: first supply / discharge oil passage,
58: second oil supply / discharge path, 61: CAN, 62: steering sensor, 63: vehicle speed sensor, 64: host ECU, 71: first microcomputer (control means),
72: 1st drive circuit, 73: 2nd microcomputer (control means), 74: 2nd drive circuit,
75: In-vehicle power supply (battery),
76u, 76v, 76w: first current sensor, 77: first rotation angle sensor,
78u, 78v, 78w: second current sensor, 79: second rotation angle sensor,
80: 1st target speed command calculating part, 81: 1st map,
82: Proportion of the first speed control, integral control unit,
85: Proportion of first q-axis current control, integral control unit,
88: Proportion of first d-axis current control, integral control unit,
91: first d / q conversion operation unit, 92: first d / q inverse conversion operation unit,
93: 1st PWM output part, 94: 1st abnormality determination part,
95: First microcomputer two-phase drive control unit, 96, 101: Differentiator (steering speed calculation means),
97, 98, 99: subtractor,
110: second target speed command calculation unit, 111: second map,
112: Proportion of second speed control, integral control unit,
115: Proportion of second q-axis current control, integral control unit,
118: Proportion of second d-axis current control, integral control unit,
121: second d / q conversion operation unit, 122: second d / q inverse conversion operation unit,
123: second PWM output unit, 124: second abnormality determination unit,
125: the second microcomputer two-phase drive controller,
126, 131: Differentiator (steering speed calculation means), 127, 128, 129: Subtractor,
θs: steering angle (steering angle detection means), ωs: steering speed, ωs0: predetermined steering speed,
v: vehicle speed,
Sf1: first electric pump abnormality determination signal,
Sf11: 1st electric pump 1-phase energization failure signal,
COM10: first electric pump normal control command,
COM11: first electric pump two-phase drive command,
COM12: first electric pump stop command,
Sf2: second electric pump abnormality determination signal,
Sf22: Second electric pump one-phase conduction failure signal,
COM20: second electric pump normal control command,
COM21: Second electric pump two-phase drive command,
COM22: Second electric pump stop command,
θ1: first rotation angle, θ2: second rotation angle,
ω1 *: first target speed command value, ω1: first rotation speed, Δω1: first speed deviation,
Iu1: U-phase actual current value of the first electric pump,
Iv1: V-phase actual current value of the first electric pump,
Iw1: W-phase actual current value of the first electric pump,
Iq1 *: first q-axis current command value, Iq1: first q-axis current value,
ΔIq1: First q-axis current deviation,
Id1 *: first d-axis current command value, Id1: first d-axis current value,
ΔId1: first d-axis current deviation,
Vq1 *: first q-axis voltage command value, Vd1 *: first d-axis voltage command value,
Vu1 *, Vv1 *, Vw1 *: First phase voltage command value during normal control,
Vu1 **, Vv1 **, Vw1 **: First phase voltage command value during two-phase drive control,
ω2 *: second target speed command value, ω2: second rotational speed, Δω2: second speed deviation,
Iu2: U-phase actual current value of the second electric pump,
Iv2: V-phase actual current value of the second electric pump,
Iw2: W-phase actual current value of the second electric pump,
Iq2 *: second q-axis current command value, Iq2: second q-axis current value,
ΔIq2: Second q-axis current deviation,
Id2 *: second d-axis current command value, Id2: second d-axis current value,
ΔId2: second d-axis current deviation,
Vq2 *: second q-axis voltage command value, Vd2 *: second d-axis voltage command value,
Vu2 *, Vv2 *, Vw2 *: Second phase voltage command value during normal control,
Vu2 **, Vv2 **, Vw2 **: Second phase voltage command value during two-phase drive control

Claims (1)

Control of a hydraulic power steering apparatus provided with first and second electric pumps for supplying hydraulic oil to a hydraulic actuator for generating an assist force for assisting a steering operation in a steering system using a three-phase brushless motor as a drive source In the device
Steering angle detection means for detecting the steering angle of the steering;
Steering speed calculating means for calculating a steering speed from the steering angle detected from the steering angle detecting means;
Control means for controlling the operation of the hydraulic actuator through supply of driving power to the three-phase brushless motor;
When the first and second electric pumps are in operation and the control means is abnormal in one phase of the three-phase brushless motor for driving one of the electric pumps, When the calculated steering speed is equal to or higher than a predetermined value, the three-phase brushless motor for driving the electric pump, which has stopped due to poor conduction in one phase, is operated in two-phase driving.
A control device for a hydraulic power steering device.

Images