JP2011218875A - Motor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor controller which reduces switching loss.SOLUTION: The motor controller includes: a motor M, which drives a pump for controlling the liquid pressure of a brake fluid pressure control device provided on a vehicle; a drive circuit 24, which includes relays 21a, 21b, 21c, 21d that turn on/off circuits for supplying electric currents to brushes 20a, 20b, 20c, 20d of the motor M; and a controller 25, which controls the relays 21a, 21b, 21c, 21d. The motor M has plus side-brushes 20a, 20c and minus-side ones 20b, 20d. The controller 25 drives the relays 21a, 21b, 21c, 21d so that one of two brushes constituting a first electrode and one brush constituting a second electrode are both energized and that the current supplying patterns of each brush is switched according to a vehicle state when the motor M is driven.

Description

  The present invention relates to a motor control device.

  In Patent Document 1, the PWM frequency for motor control is set higher than the maximum audible frequency in a normal state where noise is not allowed, and the PWM frequency is set to be equal to or lower than the maximum audible frequency in a noise allowable state where noise is allowed.

JP 2000-168545 A

However, the conventional technique has a problem that the switching loss of the drive element is large because the PWM frequency needs to be higher than the maximum audible frequency in the normal state.
An object of the present invention is to provide a motor control device that can reduce switching loss.

  In the motor control device of the present invention, when the brush motor that drives the pump of the hydraulic pressure control device provided in the vehicle is operated, a circuit that energizes the brush motor so that the energization pattern of each brush is switched according to the state of the vehicle The switching means for switching on and off is driven.

  Therefore, according to the present invention, switching loss can be reduced.

1 is a perspective view of a brake fluid pressure control device 1 according to a first embodiment. 1 is a hydraulic circuit diagram of a brake fluid pressure control device 1 of Embodiment 1. FIG. 1 is a configuration diagram of a motor control device 19 of Embodiment 1. FIG. It is a flowchart which shows the flow of the energization pattern determination process of the brush energization pattern determination part 25a of Example 1. FIG. It is a flowchart which shows the flow of the relay selection process of the relay selection part 25b of Example 1. FIG. FIG. 4 is a relationship diagram between each brush energization pattern and NT characteristics in Example 1. FIG. 3 is a circuit diagram illustrating a relationship between each brush energization pattern of Example 1 and a current supplied to a motor M. It is a figure which shows the waveform of the electric current which flows into a motor when an electric current is applied to a motor. 3 is a time chart showing a current flowing through the motor M when a voltage is applied to the motor M according to the first embodiment.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the motor control apparatus of this invention is demonstrated based on the Example shown on drawing.

[Example 1]
First, the configuration will be described.
[Brake fluid pressure control device]
FIG. 1 is a perspective view of a brake fluid pressure control device 1 according to a first embodiment. The brake fluid pressure control device 1 controls the fluid pressure of a wheel cylinder provided on each wheel of the vehicle. Placed in the engine room, DC brush motor (hereinafter referred to as motor) M, housing HG with built-in hydraulic parts such as pumps and solenoid valves, and the hydraulic circuit inside, and motor M and hydraulic parts are driven and controlled It has a brake controller ECU with an electric circuit.
FIG. 2 is a hydraulic circuit diagram of the brake fluid pressure control device 1 according to the first embodiment.
The hydraulic circuit according to the first embodiment has a piping structure called an X piping composed of two systems, a P system and an S system.
The left front wheel cylinder W / C (FL) and the right rear wheel wheel cylinder W / C (RR) are connected to the P system, and the right front wheel wheel cylinder W / C (FR), The wheel cylinder W / C (RL) on the left rear wheel is connected. Each of the P system and the S system is provided with a pump PP and a pump PS, and the pump PP and the pump PS are driven by one motor M.
The brake pedal BP is provided with a brake switch BS that detects the operation state of the brake pedal BP. The brake pedal BP is connected to the master cylinder M / C via the input rod IR. In addition, it is good also as a structure provided with the booster which boosts the input of input rod IR.

Master cylinder M / C and the suction side of pumps PP and PS (hereinafter referred to as pump P) are connected by conduits 11P and 11S (hereinafter referred to as conduit 11). On each pipeline 11, gate-in valves 2P and 2S, which are normally closed on / off solenoid valves, are provided. A pressure sensor PMC that detects the pressure of the master cylinder M / C is provided between the master cylinder M / C and the gate-in valve 2P.
In addition, check valves 6P and 6S (hereinafter referred to as check valves 6) are provided on the pipeline 11 between the gate-in valves 2P and 2S (hereinafter referred to as gate-in valves 2) and the pump P. The check valve 6 allows the flow of brake fluid in the direction from the gate-in valve 2 to the pump P and prohibits the flow in the opposite direction.
The discharge side of each pump P and each wheel cylinder W / C are connected by pipes 12P and 12S (hereinafter, pipe 12). On each pipeline 12, solenoid-in valves 4FL, 4RR, 4FR, 4RL (hereinafter referred to as solenoid-in valves 4), which are normally open proportional solenoid valves corresponding to the respective wheel cylinders W / C, are provided. .
Also, check valves 7P and 7S (hereinafter referred to as check valves 7) are provided on each pipe line 12 and between each solenoid-in valve 4 and the pump P. Each check valve 7 is connected to the pump P. Allows the brake fluid to flow in the direction toward the solenoid-in valve 4 and prohibits the flow in the opposite direction.
Furthermore, each pipeline 12 is provided with pipelines 17FL, 17RR, 17FR, 17RL (hereinafter referred to as pipeline 17) that bypass each solenoid-in valve 4. The pipeline 17 includes check valves 10FL, 10RR, 10FR, 10RL (hereinafter, check valve 10) is provided. Each check valve 10 allows the flow of brake fluid in the direction from the wheel cylinder W / C toward the pump P, and prohibits the flow in the opposite direction.

Master cylinder M / C and pipe 12 are connected by pipes 13P and 13S (hereinafter, pipe 13), and pipe 12 and pipe 13 merge between pump P and solenoid-in valve 4. On each pipeline 13, gate-out valves 3P and 3S (hereinafter referred to as gate-out valves 3), which are normally open proportional solenoid valves, are provided.
Each pipeline 13 is provided with pipelines 18P and 18S (hereinafter referred to as pipeline 18) that bypass each gate-out valve 3. The pipeline 18 includes check valves 9P and 9S (hereinafter referred to as check valve 9). ) Is provided. Each check valve 9 allows the flow of brake fluid in the direction from the master cylinder M / C side toward the wheel cylinder W / C, and prohibits the flow in the opposite direction.
On the suction side of the pump P, reservoirs 16P and 16S (hereinafter referred to as reservoir 16) are provided, and the reservoir 16 and the pump P are connected by pipe lines 15P and 15S (hereinafter referred to as pipe line 15). Check valves 8P and 8S (hereinafter referred to as check valves 8) are provided between the reservoir 16 and the pump P, and each check valve 8 allows a flow of brake fluid in the direction from the reservoir 16 to the pump P. , Prohibit flow in the opposite direction.
The wheel cylinder W / C and the pipeline 15 are connected by pipelines 14P and 14S (hereinafter, pipeline 14), and the pipeline 14 and the pipeline 15 merge between the check valve 8 and the reservoir 16. Each pipeline 14 is provided with a solenoid-out valve 5FL, 5RR, 5FR, 5RL, which is a normally closed on / off solenoid valve.
The brake controller ECU is based on the master cylinder pressure Pmc detected by the pressure sensor PMC and various vehicle information (wheel speed, vehicle acceleration), anti-skid brake control (ABS), preceding vehicle tracking control (ACC), vehicle behavior The control target value in automatic brake control such as stabilization control (VDC) is calculated, and the gate-in valve 2, gate-out valve 3, solenoid-in valve 4, solenoid-out valve 5 and motor M are driven and controlled.

[Motor control device]
FIG. 3 is a configuration diagram of the motor control device 19 according to the first embodiment. The motor control device 19 includes the motor M, a drive element 22 that controls energization of the motor M, and each brush 20a, 20b, A drive circuit 24 provided with relays (switching means) 21a, 21b, 21c, 21d for switching on / off of a circuit for energizing 20c, 20d, a controller 25 for controlling the drive element 22 and the relays 21a, 21b, 21c, 21d, Have The controller 25 is provided as part of the function of the brake controller ECU.
The motor M according to the first embodiment is a DC brush motor having four brushes 20a, 20b, 20c, and 20d. The plus side brushes 20a and 20c are connected to the battery BAT as a power source, and the minus side brushes 20b and 20d are connected to the ground GND. Between the battery BAT and the plus side brushes 20a and 20c, relays 21a and 21c for electrically connecting and disconnecting both are interposed. In addition, relays 21b and 21d are provided between the ground GND and the negative brushes 20b and 20d to electrically connect and disconnect them. The drive element 22 is interposed between the relays 21b and 21b and the ground GND.
The controller 25 includes a brush energization pattern determination unit 25a, a relay selection unit 25b, a relay drive unit 25c, and a PWM control unit 25d.
The brush energization pattern determination unit 25a determines the brush energization patterns of the four brushes 20a, 20b, 20c, and 20d according to the state of the vehicle. Each brush energization pattern has a different number of brushes energizing each other, and different NT (rotation speed-torque) characteristics can be obtained by changing the brush energization pattern. Since the motor M of Example 1 is four brush motors, the brush energization patterns are as follows.
1. Pattern A: All brushes 20a, 20b, 20c, and 20d are energized.
2. Pattern B: Energize one of the plus side brushes 20a and 20c and both the minus side brushes 20b and 20d. Or, both the plus side brushes 20a and 20c and one of the minus side brushes 20b and 20d are energized.
3. Pattern C: Energize one of the plus side brushes 20a, 20c and one of the minus side brushes 20b, 20d.
The relay selection unit 25b selects a brush to be turned on and a brush to be turned off according to the brush energization pattern determined by the brush energization pattern determination unit 25a. Also, the relay selection unit 25b accumulates the energization time (ON time) of each of the relays 21a, 21b, 21c, and 21d and stores them in the nonvolatile memory, and the brush energization pattern is determined to be B or C Are preferentially selected with a short ON time (switching means driving time detecting means). Here, the energization time stored in the memory is not erased by turning on or off the ignition key switch.
The relay drive unit 25c outputs a drive command to turn on the brush selected by the relay selection unit 25b and turn off the unselected brush to each relay 21a, 21b, 21c, 21d, and to each relay 21a, 21b, 21c, Drive 21d.
The PWM control unit 25d drives the drive element 22 at a PWM frequency smaller than the maximum audible frequency (for example, a value between 100 and 150 Hz) when the motor M is operated.

[Energization pattern determination process]
FIG. 4 is a flowchart illustrating a flow of energization pattern determination processing of the brush energization pattern determination unit 25a according to the first embodiment.
In step S1, it is determined whether or not the brake is being operated from the signal of the brake switch BS. If YES, the process proceeds to step S2, and if NO, the process proceeds to step S4.
In step S2, it is determined whether or not the vehicle is stopped based on the vehicle speed. If YES, the process proceeds to step S10, and if NO, the process proceeds to step S3.
In step S3, it is determined whether or not ABS control is being performed. If YES, the process proceeds to step S4. If NO, the process proceeds to step S6.
In step S4, it is determined whether or not there is a wheel cylinder having a high pressure increase speed. If YES, the process proceeds to step S5. If NO, the process proceeds to step S9.
In step S5, it is determined whether or not there is a wheel cylinder having a high required hydraulic pressure. If YES, the process proceeds to step S8, and if NO, the process proceeds to step S9.
In step S6, it is determined from the increasing gradient of the master cylinder pressure Pmc whether or not it is a sudden braking request. If YES, the process proceeds to step S8, and if NO, the process proceeds to step S7.
In step S7, the brush energization pattern is B.
In step S8, the brush energization pattern is A.
In step S9, the brush energization pattern is B.
In step S10, the brush energization pattern is C.

[Relay selection processing]
FIG. 5 is a flowchart illustrating a flow of the relay selection process of the relay selection unit 25b according to the first embodiment.
In step S11, the brush energization pattern determined by the brush energization pattern determination unit 25a is read.
In step S12, it is determined whether or not the brush energization pattern read in step S11 is the brush energization pattern B. If YES, the process proceeds to step S13, and if NO, the process proceeds to step S15.
In step S13, the integrated value of the ON time of each relay 21a, 21b, 21c, 21d is read from the memory.
In step S14, three relays having a small ON time integrated value are selected.
In step S15, it is determined whether or not the brush energization pattern read in step S11 is the brush energization pattern C. If YES, the process proceeds to step S17, and if NO, the process proceeds to step S16.
In step S16, all the relays 21a, 21b, 21c, and 21d are turned on, and the process proceeds to step S22.
In step S17, the integrated value of the ON time of each relay 21a, 21b, 21c, 21d is read from the memory.
In step S18, the integrated value of ON time of relay 21a read in step S17 is compared with the integrated value of ON time of relay 21c.
In step S19, the smaller relay of the integrated values of the two ON times compared in step S18 is selected, and the process proceeds to step S22.
In step S20, the integrated value of ON time of relay 21b read in step S17 is compared with the integrated value of ON time of relay 21d.
In step S21, the smaller relay is selected from the integrated values of the two ON times compared in step S20, and the process proceeds to step S22.
In step S22, the ON time of each relay in the current control cycle is added to the integrated value stored in the memory.

Next, the operation will be described.
[Energization pattern determination processing action]
(Brush conduction pattern A)
When the pressure increase speed of the wheel cylinder is high and the required hydraulic pressure is high, in the flowchart shown in FIG. 4, the process proceeds from step S1, step S2, step S3, step S4, step S5, step S8, and energizing the brush. Select pattern A.
When the depression speed of the brake pedal BP is high, the process proceeds from step S1, step S2, step S3, step S4, step S6, step S8, and the brush energization pattern A is selected.
(Brush current pattern B)
When the depression speed of the brake pedal BP is low, the process proceeds from step S1, step S2, step S3, step S6, step S7, and the brush energization pattern B is selected.
When the pressure increase speed of the wheel cylinder is low, the process proceeds from step S1, step S2, step S3, step S4, step S9, and the brush energization pattern B is selected.
If the required hydraulic pressure is low, the process proceeds from step S1, step S2, step S3, step S4, step S5, and step S9, and the brush energization pattern B is selected.
(Brush conduction pattern C)
When the vehicle stops, the process proceeds from step S1, step S2, step S3, step S10, and the brush energization pattern C is selected.

[Brush current pattern and motor characteristics]
FIG. 6 is a relationship diagram between each brush energization pattern and the NT characteristic according to the first embodiment.
In the case of the brush energization pattern A, the motor characteristics are such that the lock current I1 flows at the lock torque T1.
In the case of the brush energization pattern B, the motor characteristics are such that the lock current I2 flows when the lock torque T2. The lock torque T2 is 1/2 the lock torque T1, and the lock current I2 is 1/2 the lock current I1.
In the case of the brush energization pattern C, the motor characteristics are such that the lock current I3 flows when the lock torque T3. The lock torque T3 is 1/3 of the lock torque T1, and the lock current I3 is 1/3 of the lock current I1.
The reason why the NT characteristics are different for each brush energization pattern will be described below.
FIG. 7 is a circuit diagram showing the relationship between each brush energization pattern of Example 1 and the current supplied to the motor M, where (a) is a brush energization pattern A, (b) is a brush energization pattern B, (c ) Is a brush energization pattern C. Note that the potential difference between the battery BAT and the ground GND is V, and the resistance of each winding 23a, 23b, 23c, 23d between the brushes 20a, 20b, 20c, 20d is r.
(a) In pattern A, all relays 21a, 21b, 21c, and 21d are turned on, so the combined resistance R1 between battery BAT and ground GND is R1 = r / 4, and between battery BAT and ground GND. The flowing current I1 is I1 = 4V / r. Therefore, the currents flowing through the windings 23a, 23b, 23c, and 23d are V / r, respectively.
(b) In pattern B, relays 21a, 21b, and 21d are ON and relay 21c is OFF, so the combined resistance R2 between battery BAT and ground GND is R2 = r / 2, and between battery BAT and ground GND The current I2 flowing through I2 is I2 = 2V / r. Therefore, the currents flowing through the two windings 23a and 23d are V / r, respectively. That is, in the pattern B, the currents flowing through the windings 23a and 23d are the same as the currents flowing through the windings 23a, 23b, 23c, and 23d of the pattern A, but the number of windings through which the current flows is 1/2 that of the pattern A. Therefore, the lock torque T2 is 1/2 the lock torque T1. In the figure, an example is shown in which one of the plus side brushes 20a and 20c and both the minus side brushes 20b and 20d are energized, but both the plus side brushes 20a and 20c and the minus side brushes 20b and 20d The same result is obtained when one is energized.
(c) In pattern C, relays 21a and 21b are turned on and relays 21c and 21d are turned off, so the combined resistance R3 between battery BAT and ground is R3 = 3r / 4, and between battery BAT and ground GND The flowing current I3 is I3 = 4V / 3r. Therefore, the current flowing through the winding 23a is V / r, and the current flowing through the windings 23b, 23c, and 23d is V / 3r. That is, in the pattern C, the current flowing through the winding 23a is the same as the current flowing through the windings 23a, 23b, 23c, and 23d of the pattern A, but the current flowing through the windings 23b, 23c, and 23d is the same as the windings of the pattern A. 23a, 23b, 23c, 23d, and the current flowing through the winding 23c acts in a direction that cancels the motor torque. Become.

[Problems of conventional devices]
In a brake fluid pressure control device for a vehicle, in the case of brake control for obtaining a braking force for the purpose of emergency avoidance, the operation frequency is low and the allowable range of noise is large. However, in recent years, the operation frequency of the brake fluid pressure control device has increased along with high-function control such as automatic brake control during normal driving other than emergency avoidance, such as following vehicle tracking, lane departure prevention, and yaw moment application during turning. is doing. Further, since the brake control is continued until the vehicle is stopped or just before the stop, the demand for the operating noise of the brake hydraulic pressure control device has become strict.
Here, in the brake fluid pressure control apparatus, the most disturbing operating noise largely depends on the PWM frequency of the drive element that drives the motor. When the PWM frequency is lower than the maximum audible frequency (for example, 500 Hz), if the motor inductance is small, the motor current is not maintained during the OFF period of the drive element as shown in FIG. Will fall down. That is, since the current fluctuation is large and no current flows continuously to the motor, a large torque fluctuation is periodically generated, so that the sound of the PWM frequency can be heard. On the other hand, when the PWM frequency exceeds the maximum audible frequency as shown in FIG. 8B (for example, 20 KHz), the current change can be reduced, and the above problem does not occur.

The conventional brake fluid pressure control apparatus copes with the above problem by switching the PWM frequency of the motor control between a normal state where noise is not allowed and a sudden braking state where noise is allowed. In other words, the PWM frequency is set higher than the maximum audible frequency in the normal state, and the PWM frequency is set to the maximum audible frequency or less in the rapid braking state. The heat generation of the drive element due to PWM control in the system is suppressed to extend the life of the drive element.
However, in the conventional device, since the PWM frequency is increased in a normal state, an expensive driving element with a countermeasure against switching noise (addition of a coil, a capacitor, etc.) is required. Further, as described above, since the operation frequency in the normal state has increased in recent years, the heat generation of the drive element increases as the PWM frequency continues to be high. Therefore, in order to extend the life of the drive element, it is necessary to take heat countermeasures such as a heat radiating plate, resulting in an increase in cost and an increase in the size of the apparatus. As another option, a method of suppressing noise by setting a coil with a large inductance between the motor and the drive element or between the motor and the power source to suppress fluctuations in the current can be considered. As a result, the operation response becomes slow, and it becomes impossible to deal with a case where a high pressure increase speed comes, such as when sudden braking is requested.
That is, in the conventional apparatus, it is impossible to achieve both the realization of the hydraulic pressure characteristics in accordance with the braking request and the improvement of the silence without increasing the cost and the size of the apparatus.

On the other hand, in the motor control device 19 of the first embodiment, the PWM frequency is set to a frequency that is equal to or lower than the maximum audible frequency, and a plurality of values are selected according to the pressure increase speed of the wheel cylinder W / C and the required hydraulic pressure when the vehicle is running and stopped. The brush energization pattern is switched. That is, by changing the NT characteristic of the motor M in accordance with the scene instead of changing the PWM frequency, both the braking request and the quietness are achieved.
[Longer life of drive element]
Since the PWM frequency for driving the motor M is suppressed to a low frequency (a value between 100 and 150 Hz) lower than the maximum audible frequency, the switching loss can be reduced, and the heat generation of the drive element 22 can be reduced. Therefore, the life of the drive element 22 can be increased without increasing the cost and increasing the size of the device due to countermeasures against switching noise and heat generation.

[Achieving both hydraulic characteristics and improved quietness in response to braking requirements]
FIG. 9 is a time chart showing a current that flows through the motor M when a voltage is applied to the motor M according to the first embodiment. At the moment when the motor M operates, the motor M has a lock current as an inrush current (inrush current). And a lock torque proportional to the lock current is generated. Since the excitation torque acts on the motor itself by this lock torque, the brake fluid pressure control device 1 vibrates and becomes operating noise. In the first embodiment, since the PWM frequency is set to a frequency equal to or lower than the maximum audible frequency, a lock current flows as an inrush current when the drive element 22 is turned on as described above.
Therefore, in the first embodiment, the NT characteristic of the motor M is switched according to the running state (during running and when stopped), the pressure increase speed of the wheel cylinder W / C, and the required hydraulic pressure, thereby reducing the magnitude of the inrush current. It has changed. As shown in FIG. 9, the lock current I1 of the brush energization pattern A is the largest, the lock current I2 of the brush energization pattern B is 1/2 of I1, and the lock current I3 of the brush energization pattern C is 1/3 of I1. .
That is, in a scene where high fluid pressure and high responsiveness are required at the time of sudden braking, the brush energization pattern A is selected and MT characteristics are set so that high torque can be obtained. At this time, although the inrush current becomes large, the operating noise of the brake fluid pressure control device 1 is difficult for the occupant to hear during sudden braking, and even if it is heard, the silence is not required.
On the other hand, in a scene where quietness is required at the time of gentle braking than at the time of sudden braking, the brush noise pattern B is selected and the operating noise is suppressed by reducing the inrush current. At this time, it switches to the NT characteristic that the lock torque becomes 1/2 with respect to the brush energization pattern A. However, the brake performance is not hindered because a high hydraulic pressure and high responsiveness are not required during slow braking.
In scenes that require the most silence, such as when the vehicle is stopped, the brush energization pattern C is selected to minimize the operating noise. In addition, although it switches to the NT characteristic in which a lock torque becomes 1/3 with respect to the brush energization pattern C, since the wheel cylinder pressure that maintains the stopped state is small, the vehicle does not start moving.
As described above, by changing the NT characteristics of the motor M according to the driving condition (during driving and stopping), the wheel cylinder W / C pressure increase speed, and the required hydraulic pressure, the hydraulic pressure characteristics that meet the braking requirements are achieved. And improvement of quietness can be achieved.

[Improved brush durability]
In the brush energization pattern B, it is only necessary to energize one of the plus side brushes 20a, 20c or the minus side brush 20b, 20d, so when the energized brush is fixed to one side, only the brush is worn, Durability deteriorates. This problem also occurs in the brush energization pattern C.
Therefore, in the first embodiment, the relay selection process shown in FIG. 5 is executed. In the relay selection process, when the brush energization pattern B is selected by the energization pattern determination process, the process proceeds to step S11 → step S12 → step S13 → step S14, and the three relays excluding the relay having the longest ON time are selected. . Thereby, the variation in the amount of wear of each brush 20a, 20b, 20c, 20d can be reduced, and durability can be improved.
On the other hand, in the relay selection process, when the brush energization pattern C is selected by the energization pattern determination process, the process proceeds from step S11 → step S12 → step S15 → step S17 → step S18 → step S19 → step S20 → step S21 One of 21a and 21c having a shorter ON time and one of relays 21b and 21d having a shorter ON time are selected. Thereby, the variation in the amount of wear of each brush 20a, 20b, 20c, 20d can be reduced, and durability can be improved.
[Cost control]
In the first embodiment, a brush motor is used as the motor M that drives the pump P. Here, by using a brushless motor instead of the brush motor, it is possible to achieve the purpose of extending the life and improving the quietness. However, the brushless motor has a built-in rotation angle sensor and electronic circuit, so the brush motor It is expensive compared with. Further, when the current is large, the driving element is also expensive. In other words, in the first embodiment, an inexpensive brush motor is used to reduce the cost, while realizing a long life and an improvement in quietness.
In the first embodiment, the four relays 21a, 21b, 21c, and 21d constituting the drive circuit 24 are turned on / off when switching the brush energization pattern, and the switching speed such as the PWM frequency is Since it is unnecessary, an inexpensive one can be used.
In other words, the motor control device 19 according to the first embodiment has a configuration for realizing both the realization of the hydraulic pressure characteristics in accordance with the braking request and the improvement of the quietness, with inexpensive components (brush motor M, drive element 22). And relays 21a, 21b, 21c, 21d).

Next, the effect will be described.
The motor control device 19 according to the first embodiment has the following effects.
(1) Switch on / off of the motor M that drives the pump P for controlling the hydraulic pressure of the brake hydraulic pressure control device 1 provided in the vehicle and the circuit that energizes the brushes 20a, 20b, 20c, and 20d of the motor M A drive circuit 24 including relays 21a, 21b, 21c, and 21d, and a controller 25 that controls the relays 21a, 21b, 21c, and 21d, and a motor M includes plus-side brushes 20a and 20c and a minus-side brush 20b 20d, when the motor M is driven, one of the two brushes forming the first electrode and one brush forming the second electrode are energized together, and each controller 25 Relays 21a, 21b, 21c, and 21d are driven so that the brush energization patterns are switched. That is, by switching the energization pattern of each brush 20a, 20b, 20c, 20d according to the vehicle state, the drive element 22 can be driven at a low frequency that is equal to or lower than the maximum audible frequency, so that switching loss can be reduced.
(2) The controller 25 determines the energization pattern based on the pressure increase speed or required hydraulic pressure of the wheel cylinder hydraulic pressure, and energization increases the number of brushes energized when the pressure increase speed or required hydraulic pressure is high compared to when it is low. A pattern. That is, as the number of brushes to be energized is increased, the motor performance can be increased while the operating noise is increased. Conversely, as the number of energized brushes is reduced, the operating noise can be reduced while the motor performance is lowered. Therefore, when the pressure increase speed or the required hydraulic pressure is high, the energization pattern increases the number of brushes to be energized compared to when it is low, so that both the realization of hydraulic pressure characteristics in response to the braking request and the improvement of quietness can be achieved. You can plan.
(3) The controller 25 selects and drives a switching relay with a short ON time among the relays 21a, 21b, 21c, and 21d. That is, the ON time of each relay 21a, 21b, 21c, 21d is equal to the ON time of each corresponding brush 20a, 20b, 20c, 20d, so by detecting the ON time of each relay 21a, 21b, 21c, 21d The ON time of each brush 20a, 20b, 20c, 20d can be determined. Then, when there are a plurality of ON / OFF combinations of the relays 21a, 21b, 21c, and 21d that can obtain the same energization pattern, each brush 20a is selected by selecting a combination that turns on the relay with a short energization time. , 20b, 20c, 20d can be reduced in variation in wear amount, and durability can be improved.

[Other Examples]
As mentioned above, although the form for implementing this invention was demonstrated based on the Example, the specific structure of this invention is not limited to the structure shown in the Example, The range which does not deviate from the summary of invention. Such design changes are included in the present invention.
The PWM frequency of the drive element 22 is preferably a value between 100 and 150 Hz as shown in the first embodiment, but may be 500 Hz or less.
In the first embodiment, four brush motors have been described. However, the present invention can be applied to three or more brush motors.
In Example 1, although the example which switches three brush energization patterns was shown, you may switch two brush energization patterns like A and B or A and C. FIG.
The brush energization pattern C may be selected in step S9 in FIG. Alternatively, the brush energization pattern B may be selected in step S10.

P pump
W / C wheel cylinder
1 Brake fluid pressure control device
19 Motor controller
20a, 20b, 20c, 20d brush
21a, 21b, 21c, 21d Relay (switching means)
24 Drive circuit
25 Controller
25b Relay selector (switching means drive time detection means)

Claims (3)

A brush motor for driving a pump for controlling the hydraulic pressure of a hydraulic pressure control device provided in the vehicle;
A drive circuit comprising switching means for switching on and off a circuit for energizing each brush of the brush motor;
A controller for controlling the switching means;
With
The brush motor has at least three brushes: two brushes forming a first electrode and one brush forming a second electrode having a different polarity from the first electrode;
The controller is configured to energize one of the two brushes constituting the first electrode and one brush constituting the second electrode when the brush motor is operated, and energize each brush according to the state of the vehicle. A motor control device that drives the switching means so that the patterns are switched. The motor control device according to claim 1,
The hydraulic pressure control device is a brake hydraulic pressure control device that controls the hydraulic pressure of a wheel cylinder provided on a wheel of the vehicle,
The brush motor includes two brushes forming the first electrode and two brushes forming the second electrode,
The controller determines the energization pattern based on the pressure increase speed or the required hydraulic pressure of the wheel cylinder hydraulic pressure, and the number of brushes to be energized increases when the pressure increase speed or the required hydraulic pressure is high compared to when it is low. A motor control device having an energization pattern. In the motor control device according to claim 1 or 2,
A switching means driving time detecting means for detecting an ON time of the switching means is provided;
The controller is configured to select and drive the switching means having a short on-time among the switching means.

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