JP2016002888A - Vehicle brake device and method for detecting electrical angle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle brake device that can accurately generate brake fluid pressure on the basis of an electrical angle of an electric motor, and a method for detecting an electrical angle that can be applied for detection of an electrical angle of an electric motor equipped on an electric brake device.SOLUTION: The vehicle brake device comprises control means 150 which detects electrical angles θ, at measurement points P at which a combination of output states of detection signals (Sig_U, Sig_V and Sig_W) that are outputted by Hall sensors 701U, 701V and 701W is changed, and estimates, between the measurement point P and the measurement point P, the electrical angles θ. In the method for detecting electrical angles, the electrical angles θ are detected when a combination of magnetic poles of a rotor 702 which are detected by the Hall sensors 701U, 701V and 701W is changed, and the electrical angles θ are estimated for a period after the combination of the magnetic poles of the rotor 702 is changed until the combination is changed again.

Description

  The present invention relates to a vehicle brake device and an electrical angle detection method for detecting an electrical angle of an electric motor provided in the vehicle brake device.

  A technique for detecting the electrical angle of an electric motor with a sensor using a Hall IC (Hall sensor) is widely used. For example, Patent Document 1 describes a technology that includes three sensors using Hall ICs and detects the electrical angle of a brushless motor.

Japanese Patent No. 3500348

As described in Patent Document 1, when the electrical angle of an electric motor is detected by a Hall sensor using a Hall IC, the electrical angle is detected based on detection signals output from the three Hall sensors. In this configuration, only the electrical angle of the measurement point set every 60 degrees can be detected, and the detection error becomes large at the measurement point.
For example, the electric brake device adjusts the brake fluid pressure to be generated based on the electrical angle of the electric motor for generating the brake fluid pressure. Therefore, if the electrical angle detection error is large, the brake fluid pressure cannot be generated with high accuracy.

  Therefore, the present invention provides a vehicle brake device capable of generating brake hydraulic pressure with high accuracy based on the electric angle of the electric motor, and an electric angle detection method applicable to detection of the electric angle of the electric motor provided in the vehicle brake device. The task is to do.

  In order to solve the above-described problems, the present invention provides a hydraulic pressure generating means for generating a brake hydraulic pressure by driving an electric motor, a plurality of hall sensors for detecting an electric angle of the electric motor, and a driver operating a brake operating unit. The vehicle brake device includes: a control unit that controls the electric motor based on the electrical angle so that a brake fluid pressure corresponding to an operation amount is generated. Each of the plurality of Hall sensors detects a magnetic pole of a rotor rotating in the electric motor, and outputs a detection signal whose output state changes according to a change in the detected magnetic pole. The electrical angle is detected every time the combination of the output states of the detection signals changes, and the electrical angle is estimated between the change of the combination of the output states and the next change of the combination of the output states. It is characterized by doing.

  According to the present invention, it is possible to estimate the electrical angle while the combination of the output states of the detection signals output from the Hall sensor does not change, and use the estimated value as the detected value of the electrical angle. Thereby, the detection error of the electrical angle by the control means can be reduced. Therefore, the control means can control the hydraulic pressure generating means based on the electrical angle detected with a small detection error, and can generate the brake hydraulic pressure with high accuracy by the hydraulic pressure generating means.

  Further, the control means of the present invention is based on the elapsed time from the change in the combination of the output states one time before the change in the combination of the output states until the next change in the combination of the output states. The electrical angle between is estimated.

  The interval (elapsed time) at which the combination of detection signal output states changes is determined by the rotational speed of the rotor and does not change abruptly. In other words, the elapsed time from the change in the combination of the output states one time before the change in the combination of the current output states does not greatly differ from the elapsed time until the next combination of the output states changes. Therefore, the electrical angle can be estimated with higher accuracy by estimating the electrical angle based on the elapsed time from the change in the combination of the previous output state to the change in the combination of the current output state.

  In addition, when the rotation direction of the rotor is switched, the control means of the present invention detects the electrical angle based on the combination of output states until the next combination of output states changes. And

When the rotation direction of the rotor is switched, the elapsed time until the next combination of output states changes, which increases the difference between the actual electrical angle and the estimated electrical angle, resulting in detection errors. May be larger.
According to the present invention, when the rotation direction of the rotor is switched, the control means detects the electrical angle based on the combination of output states. As a result, the electrical angle detection error can be reduced.

  Further, the control means of the present invention estimates the electrical angle within a range that does not exceed a change amount in which the electrical angle changes from when the combination of the output states changes to when the combination of the output states changes next time. It is characterized by doing.

The amount of change in the electrical angle from the change in the combination of the output states of the output signals to the next change in the combination of the output states of the output signals is determined by the arrangement of the Hall sensors.
According to the present invention, the control means can calculate the estimated value of the electrical angle within a range that does not exceed the change amount of the electrical angle while the combination of the output states of the output signals changes. The value calculation is suppressed.

Further, the present invention is characterized in that the three Hall sensors are arranged around the rotor at intervals of 120 degrees.
According to the present invention, the control means can detect the electrical angle at intervals of 60 degrees.

  Further, according to the present invention, the control means uses the detection signal that is output from a plurality of Hall sensors that detect the magnetic poles of the rotor rotating in the electric motor, and the output state changes according to the detected change of the magnetic poles. An electrical angle detection method for detecting an electrical angle of an electric motor is provided. The control means detects the electrical angle based on the combination of the output states each time the combination of the output states of the detection signals output from the plurality of Hall sensors changes, and the output state The electrical angle is estimated until the next combination of output states is changed after the combination is changed.

  According to the present invention, the electrical angle can be detected when the combination of the output states of the output signals output from the plurality of Hall sensors changes, and the electrical angle can be estimated while the combination of the output states of the output signals does not change.

  Further, according to the present invention, the control unit changes the combination of the output states next based on an elapsed time from the change of the combination of the output states one time before the change of the combination of the output states this time. The electrical angle up to is estimated.

  The interval (elapsed time) at which the combination of detection signal output states changes is determined by the rotational speed of the rotor and does not change abruptly. In other words, the elapsed time from the change in the combination of the output states one time before the change in the combination of the current output states does not greatly differ from the elapsed time until the next combination of the output states changes. Therefore, the electrical angle can be estimated with high accuracy by estimating the electrical angle based on the elapsed time from the change in the combination of the output states one time before the change in the combination of the current output states.

  In the present invention, when the rotation direction of the rotor is switched, the control unit detects the electrical angle based on the combination of the output states until the next combination of the output states is changed. And

When the rotation direction of the rotor is switched, the elapsed time until the next combination of output states changes, which increases the difference between the actual electrical angle and the estimated electrical angle, resulting in detection errors. May be larger.
According to the present invention, when the rotation direction of the rotor is switched, the electrical angle is detected based on the combination of output states. This reduces the electrical angle detection error.

  Further, the present invention provides the control means, wherein the electrical angle is set so that a change amount of the electrical angle does not exceed a change between the change of the output state and the next change of the output state combination. It is characterized by estimating.

The amount of change in the electrical angle from the change in the combination of the output states of the detection signals to the next change in the combination of the output states is determined by the arrangement of the Hall sensors.
According to the present invention, since the electrical angle is estimated within a range that does not exceed the amount of change in which the electrical angle changes while the combination of output states changes, the electrical angle is prevented from being estimated to be larger than the practical range. Is done.

Further, the present invention is characterized in that the control means uses the detection signals output from the hall sensors arranged at intervals of 120 degrees around the rotor.
According to the present invention, it is possible to detect electrical angles at intervals of 60 degrees.

  According to the present invention, it is possible to provide a vehicular brake device capable of accurately generating a brake fluid pressure based on an electric angle of an electric motor, and an electric angle detection method applicable to detection of an electric angle of an electric motor provided in the vehicular brake device. .

1 is a schematic configuration diagram of a vehicle brake system. (A) is a figure which shows the Hall sensor which detects the electrical angle of an electric motor, (b) is a figure which shows the detection signal which a Hall sensor outputs, (c) is the electrical angle which a control means calculates, and an actual angle It is a figure which shows an electrical angle. It is a figure explaining estimation of an electrical angle. (A) is a figure which shows an estimated electrical angle line, (b) is a figure which shows the state which suppresses the change of an estimated value within 60 degree | times. It is a figure which shows the state in which an actual electrical angle reduces with progress of time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a schematic configuration diagram of a vehicle brake system.

As shown in FIG. 1, the vehicle brake device (vehicle brake system 10) according to the present embodiment has a hydraulic pressure corresponding to an operation input when a driver operates a brake operation unit such as a brake pedal 12. A hydraulic pressure generator (input device 14) that generates (brake hydraulic pressure) in the brake fluid that is hydraulic fluid, and a pedal stroke sensor St that measures an operation amount (stroke) when the brake pedal 12 is depressed. The motor cylinder device 16 and a vehicle behavior stabilization device 18 (hereinafter referred to as VSA (vehicle stability assist) device 18, referred to as VSA; registered trademark) for assisting the stabilization of the vehicle behavior are configured.
The motor cylinder device 16 operates the operating pressure (brake fluid pressure) supplied to the wheel cylinders 32FR, 32RL, 32RR, 32FL of each wheel (right front wheel WFR, left rear wheel WRL, right rear wheel WRR, left front wheel WFL). Occurs in fluid (brake fluid).

  These input device 14, motor cylinder device 16, and VSA device 18 are connected by, for example, a pipe line (hydraulic pressure path) formed of a pipe material such as a hose or a tube, and a by-wire type brake. As a system, the input device 14 and the motor cylinder device 16 are electrically connected by a harness (not shown).

  Among these, the hydraulic path will be described. The connection port 20a of the input device 14 and the connection point A1 are connected by the first piping tube 22a with reference to the connection point A1 in FIG. 1 (slightly below the center). The output port 24a of the motor cylinder device 16 and the connection point A1 are connected by the second piping tube 22b, and the introduction port 26a of the VSA device 18 and the connection point A1 are connected by the third piping tube 22c.

  With reference to the other connection point A2 in FIG. 1, the other connection port 20b of the input device 14 and the connection point A2 are connected by the fourth piping tube 22d, and the other output port 24b of the motor cylinder device 16 The connection point A2 is connected by the fifth piping tube 22e, and the other introduction port 26b of the VSA device 18 and the connection point A2 are connected by the sixth piping tube 22f.

  The VSA device 18 is provided with a plurality of outlet ports 28a to 28d. The first outlet port 28a is connected to the wheel cylinder 32FR of the disc brake mechanism 30a provided on the right front wheel WFR by the seventh piping tube 22g. The second outlet port 28b is connected to a wheel cylinder 32RL of the disc brake mechanism 30b provided on the left rear wheel WRL by an eighth piping tube 22h. The third outlet port 28c is connected to the wheel cylinder 32RR of the disc brake mechanism 30c provided on the right rear wheel WRR by the ninth piping tube 22i. The fourth outlet port 28d is connected to a wheel cylinder 32FL of the disc brake mechanism 30d provided on the left front wheel WFL by a tenth piping tube 22j.

  In this case, the brake fluid is supplied to the wheel cylinders 32FR, 32RL, 32RR, 32FL of the disc brake mechanisms 30a-30d by the piping tubes 22g-22j connected to the outlet ports 28a-28d, and the wheel cylinders 32FR, 32FR, As the brake fluid pressure in 32RL, 32RR, and 32FL increases, each wheel cylinder 32FR, 32RL, 32RR, and 32FL is operated, and the corresponding wheel (right front wheel WFR, left rear wheel WRL, right rear wheel WRR, left front wheel). WFL) increases the frictional force, and braking force is applied.

  The right front wheel WFR, the left rear wheel WRL, the right rear wheel WRR, and the left front wheel WFL are provided with wheel speed sensors 35a, 35b, 35c, and 35d, respectively, for detecting the wheel speed, and the wheel speed sensors 35a and 35b are provided. , 35c, and 35d measure the wheel speed of each wheel and are input to the control means 150.

  The electric motor 200 that generates the driving force of the vehicle is provided in the vehicle so as to drive the two front wheels (the right front wheel WFR and the left front wheel WFL) with power. In this case, the two front wheels are drive wheels, and the two rear wheels (left rear wheel WRL, right rear wheel WRR) are non-drive wheels.

A regenerative control device 201 is connected to the electric motor 200. The regenerative control device 201 has a function of charging the battery 202 with electric power (regenerative electric power) generated by the electric motor 200 with torque input from the drive wheels, and is controlled by a command input from the control means 150. For example, when a command for generating regenerative electric power by the electric motor 200 to generate a regenerative braking force is input from the control unit 150, the regenerative control device 201 switches the electric motor 200 to “generator” and regenerates the electric power generated by the electric motor 200. It functions to charge the battery 202 with power. Further, the regenerative control device 201 is configured to be able to adjust the strength of the regenerative braking force by the electric motor 200, for example, by changing the field current supplied to the electric motor 200 and adjusting the amount of electric power generated by the electric motor 200. Is done.
Note that the regenerative control device 201 may control the electric motor 200 to generate a regenerative braking force using a known technique.

  The input device 14 includes a tandem master cylinder 34 that can generate hydraulic pressure in the brake fluid by operating the brake pedal 12 by the driver, and a reservoir (first reservoir 36) attached to the master cylinder 34. In the cylinder tube 38 of the master cylinder 34, two pistons (secondary piston 40a and primary piston 40b) spaced apart by a predetermined distance along the axial direction of the cylinder tube 38 are slidably disposed. The secondary piston 40 a is disposed close to the brake pedal 12 and is connected to the brake pedal 12 via the push rod 42. Further, the primary piston 40b is arranged farther from the brake pedal 12 than the secondary piston 40a.

  Further, on the inner wall of the cylinder tube 38, a pair of ring-shaped cup seals 44Pa and 44Pb slidably contacting the outer periphery of the primary piston 40b, and a pair of ring-shaped cup seals 44Sa and 44Sb slidably contacting the outer periphery of the secondary piston 40a. Is installed. Further, a spring member 50a is disposed between the secondary piston 40a and the primary piston 40b, and another spring member 50b is disposed between the primary piston 40b and the side end portion 38a on the closed end side of the cylinder tube 38. Established.

A guide rod 48b extends from the side end 38a of the cylinder tube 38 along the sliding direction of the primary piston 40b, and the primary piston 40b slides while being guided by the guide rod 48b.
A guide rod 48a extends from the end of the primary piston 40b on the secondary piston 40a side along the sliding direction of the secondary piston 40a, and the secondary piston 40a slides while being guided by the guide rod 48a.
The secondary piston 40a and the primary piston 40b are connected by a guide rod 48a and arranged in series.

The cylinder tube 38 of the master cylinder 34 has two supply ports (second supply port 46a and first supply port 46b), two relief ports (second relief port 52a and first relief port 52b), Two output ports 54a and 54b are provided. In this case, the second supply port 46a, the first supply port 46b, the second relief port 52a, and the first relief port 52b are provided so as to join and communicate with a reservoir chamber (not shown) in the first reservoir 36, respectively.
Further, the pair of cup seals 44Sa and 44Sb that are in sliding contact with the outer periphery of the secondary piston 40a are disposed with the second relief port 52a interposed in the sliding direction of the secondary piston 40a. Further, the pair of cup seals 44Pa and 44Pb slidably in contact with the outer periphery of the primary piston 40b is disposed with the first relief port 52b interposed in the sliding direction of the primary piston 40b.

Further, in the cylinder tube 38 of the master cylinder 34, a second pressure chamber 56a and a first pressure chamber 56b that generate a hydraulic pressure corresponding to the depression force that the driver steps on the brake pedal 12 are provided. The second pressure chamber 56a is provided so as to communicate with the connection port 20a via the second hydraulic pressure path 58a, and the first pressure chamber 56b communicates with the other connection port 20b via the first hydraulic pressure path 58b. To be provided.
A space between the first pressure chamber 56b and the second pressure chamber 56a is liquid-tightly sealed by a pair of cup seals 44Pa and 44Pb. Further, the brake pedal 12 side of the second pressure chamber 56a is liquid-tightly sealed by a pair of cup seals 44Sa and 44Sb.

The first pressure chamber 56b is configured to generate a hydraulic pressure corresponding to the displacement of the primary piston 40b, and the second pressure chamber 56a is configured to generate a hydraulic pressure corresponding to the displacement of the secondary piston 40a. .
The secondary piston 40 a is connected to the brake pedal 12 via the push rod 42 and is displaced in the cylinder tube 38 with the operation of the brake pedal 12. Further, the primary piston 40b is displaced by the hydraulic pressure generated in the second pressure chamber 56a by the displacement of the secondary piston 40a. That is, the primary piston 40b is displaced in response to the secondary piston 40a.

  Between the master cylinder 34 and the connection port 20a, a pressure sensor Pm is disposed on the upstream side of the second hydraulic pressure path 58a, and a normally open type is provided on the downstream side of the second hydraulic pressure path 58a. A second shut-off valve 60a composed of a (normally open) solenoid valve is provided. The pressure sensor Pm measures the hydraulic pressure upstream of the second shutoff valve 60a on the master cylinder 34 side on the second hydraulic pressure path 58a.

  Between the master cylinder 34 and the other connection port 20b, on the upstream side of the first hydraulic pressure path 58b, a first shutoff valve 60b composed of a normally open type (normally open type) solenoid valve is provided. A pressure sensor Pp is provided on the downstream side of the first hydraulic pressure path 58b. This pressure sensor Pp measures the hydraulic pressure downstream of the wheel cylinders 32FR, 32RL, 32RR, 32FL from the first shutoff valve 60b on the first hydraulic pressure path 58b.

  The normal open in the second shut-off valve 60a and the first shut-off valve 60b is a valve configured such that the normal position (the position of the valve body when not energized) is in the open position (normally open). Say. In FIG. 1, the second shut-off valve 60 a and the first shut-off valve 60 b respectively show valve closed states in which solenoids are energized and valve bodies (not shown) are activated.

  A branch hydraulic pressure path 58c branched from the first hydraulic pressure path 58b is provided in the first hydraulic pressure path 58b between the master cylinder 34 and the first shutoff valve 60b, and the branched hydraulic pressure path 58c includes A third shut-off valve 62 composed of a normally closed type (normally closed type) solenoid valve and a stroke simulator 64 are connected in series. The normal close in the third shut-off valve 62 refers to a valve configured such that the normal position (the position of the valve body when not energized) is in the closed position (normally closed). In FIG. 1, the third shut-off valve 62 shows a valve open state in which a solenoid (not shown) is actuated by energizing a solenoid.

  The stroke simulator 64 is a device that gives a stroke and reaction force to the depression operation of the brake pedal 12 during the by-wire control, and makes the driver feel as if braking force is generated by the depression force. The first hydraulic pressure path 58b is disposed closer to the master cylinder 34 than the first shutoff valve 60b. The stroke simulator 64 is provided with a hydraulic pressure chamber 65 communicating with the branch hydraulic pressure path 58c, and brake fluid (brake fluid) led out from the first pressure chamber 56b of the master cylinder 34 via the hydraulic pressure chamber 65 is provided. ) Is provided so as to be absorbable.

The stroke simulator 64 is a simulator that is urged by a first return spring 66a having a high spring constant, a second return spring 66b having a low spring constant, and the first and second return springs 66a and 66b arranged in series. A piston 68, the pedal reaction force of the brake pedal 12 is set to be low when the brake pedal 12 is depressed, and the pedal reaction force of the brake pedal 12 is set high when the brake pedal 12 is depressed late. It is provided to be equivalent to the pedal feeling when the stepping operation is performed.
That is, the stroke simulator 64 is configured to generate a reaction force corresponding to the hydraulic pressure of the brake fluid derived from the first pressure chamber 56 b and to apply the reaction force to the brake pedal 12 via the master cylinder 34. .

  The hydraulic pressure path is roughly divided into a second hydraulic pressure system 70a that connects the second pressure chamber 56a of the master cylinder 34 and the plurality of wheel cylinders 32FR, 32RL, a first pressure chamber 56b of the master cylinder 34, and a plurality of pressure paths. The first hydraulic system 70b is connected to the wheel cylinders 32RR and 32FL.

  The second hydraulic system 70a includes a second hydraulic path 58a that connects the output port 54a of the master cylinder 34 (cylinder tube 38) and the connection port 20a in the input device 14, and the connection port 20a of the input device 14 and the motor cylinder. Piping tubes 22a and 22b connecting the output port 24a of the device 16, piping tubes 22b and 22c connecting the output port 24a of the motor cylinder device 16 and the introduction port 26a of the VSA device 18, and a lead-out port of the VSA device 18 28a, 28b and pipe tubes 22g, 22h connecting the wheel cylinders 32FR, 32RL, respectively.

  The first hydraulic system 70b includes a first hydraulic path 58b that connects the output port 54b of the master cylinder 34 (cylinder tube 38) in the input device 14 and the other connection port 20b, and another connection port of the input device 14. Piping tubes 22d and 22e for connecting 20b and the output port 24b of the motor cylinder device 16, piping tubes 22e and 22f for connecting the output port 24b of the motor cylinder device 16 and the introduction port 26b of the VSA device 18, and a VSA device 18 lead-out ports 28c, 28d and pipe tubes 22i, 22j connecting the wheel cylinders 32RR, 32FL, respectively.

  The motor cylinder device 16 includes an electric motor (electric motor 72), an actuator mechanism 74, and a cylinder mechanism 76 biased by the actuator mechanism 74, and functions as a hydraulic pressure generating means in this embodiment.

The actuator mechanism 74 is provided on the output shaft 72 b side of the electric motor 72, and a gear mechanism (deceleration mechanism) 78 that transmits a rotational driving force of the electric motor 72 through meshing of a plurality of gears. The ball screw structure 80 includes a ball screw shaft 80a and a ball 80b that move forward and backward along the axial direction when the rotational driving force is transmitted.
In the present embodiment, the ball screw structure 80 is housed in the mechanism housing portion 173 a of the actuator housing 172 together with the gear mechanism 78.

The cylinder mechanism 76 includes a substantially cylindrical cylinder body 82 and a second reservoir 84 attached to the cylinder body 82. The second reservoir 84 is connected to the first reservoir 36 attached to the master cylinder 34 of the input device 14 by a piping tube 86, and the brake fluid stored in the first reservoir 36 is passed through the piping tube 86 to the second reservoir 84. 84 is provided so as to be supplied in the inside. Note that the piping tube 86 may be provided with a tank for storing brake fluid.
An open end (open end) of the cylinder body 82 having a substantially cylindrical shape is fitted into an actuator housing 172 including a housing body 172F and a housing cover 172R, and the cylinder body 82 and the actuator housing 172 are coupled to each other. A cylinder device 16 is configured.

  In the cylinder body 82, a second slave piston 88a and a first slave piston 88b that are spaced apart from each other by a predetermined distance along the axial direction of the cylinder body 82 are slidably disposed. The second slave piston 88a is disposed in the vicinity of the ball screw structure 80, contacts the one end of the ball screw shaft 80a, and is displaced integrally with the ball screw shaft 80a in the direction of the arrow X1 or X2. The first slave piston 88b is arranged farther from the ball screw structure 80 side than the second slave piston 88a.

Further, the electric motor 72 in the present embodiment is configured to be covered with a motor casing 72a formed separately from the cylinder body 82, and the output shaft 72b slides between the second slave piston 88a and the first slave piston 88b. It arrange | positions so that it may become substantially parallel to (axial direction).
The rotational drive of the output shaft 72b is transmitted to the ball screw structure 80 via the gear mechanism 78.

  The gear mechanism 78 is, for example, a third gear 78a that is attached to the output shaft 72b of the electric motor 72 and a ball 80b that moves the ball screw shaft 80a back and forth in the axial direction about the axis of the ball screw shaft 80a. The gear 78c is composed of three gears, a second gear 78b that transmits the rotation of the first gear 78a to the third gear 78c, and the third gear 78c rotates around the axis of the ball screw shaft 80a.

  The actuator mechanism 74 in the present embodiment converts the rotational driving force of the output shaft 72b of the electric motor 72 into the advancing / retreating driving force (linear driving force) of the ball screw shaft 80a by the structure described above.

A pair of slave cup seals 90a and 90b are mounted on the outer peripheral surface of the first slave piston 88b via an annular stepped portion. A first back chamber 94b communicating with a reservoir port 92b described later is formed between the pair of slave cup seals 90a and 90b.
A second return spring 96a is disposed between the second and first slave pistons 88a and 88b, and a first return spring 96b is provided between the first slave piston 88b and the side end of the cylinder body 82. Is disposed.

An annular guide piston 90c that seals between the outer peripheral surface of the second slave piston 88a and the mechanism housing portion 173a in a fluid-tight manner and guides the second slave piston 88a so as to be movable in the axial direction. The cylinder body 82 is provided as a seal member behind the second slave piston 88a. It is preferable that a slave cup seal (not shown) is attached to the inner peripheral surface of the guide piston 90c through which the second slave piston 88a penetrates, and the second slave piston 88a and the guide piston 90c are liquid-tightly configured. Further, a slave cup seal 90b is attached to the front outer peripheral surface of the second slave piston 88a via an annular step portion.
With this configuration, the brake fluid filled in the cylinder body 82 is sealed in the cylinder body 82 by the guide piston 90c and does not flow into the actuator housing 172 side.
A second back chamber 94a communicating with a reservoir port 92a described later is formed between the guide piston 90c and the slave cup seal 90b.

  The cylinder body 82 of the cylinder mechanism 76 is provided with two reservoir ports 92a and 92b and two output ports 24a and 24b. In this case, the reservoir port 92a (92b) is provided so as to communicate with a reservoir chamber (not shown) in the second reservoir 84.

  Further, in the cylinder body 82, a second hydraulic pressure chamber 98a for controlling the brake hydraulic pressure output from the output port 24a to the wheel cylinders 32FR, 32RL side, and the other output port 24b to the wheel cylinders 32RR, 32FL side. A first hydraulic pressure chamber 98b for controlling the output brake hydraulic pressure is provided.

According to this configuration, the second back chamber 94a, the first back chamber 94b, the second hydraulic chamber 98a, and the first hydraulic chamber 98b in which the brake fluid is sealed are brake fluid sealing portions in the cylinder body 82. The guide piston 90c, which functions as a seal member, is partitioned liquid-tight (air-tight) from the mechanism housing portion 173a of the actuator housing 172.
Note that the method of attaching the guide piston 90c to the cylinder body 82 is not limited. For example, the guide piston 90c may be attached with a circlip (not shown).

  A regulating means for regulating the maximum stroke (maximum displacement distance) and the minimum stroke (minimum displacement distance) of the second slave piston 88a and the first slave piston 88b between the second slave piston 88a and the first slave piston 88b. 100 is provided. Further, the first slave piston 88b is provided with a stopper pin 102 that restricts the sliding range of the first slave piston 88b and prevents an overreturn to the second slave piston 88a side. At the time of backup braking at 34, when one system fails, the other system is prevented from failing.

  The VSA device 18 is a known one, and a second brake system that controls a second hydraulic system 70a connected to the disc brake mechanisms 30a, 30b (wheel cylinders 32FR, 32RL) of the right front wheel WFR and the left rear wheel WRL. 110a and a first brake system 110b for controlling the first hydraulic system 70b connected to the disc brake mechanisms 30c, 30d (wheel cylinders 32RR, 32FL) of the right rear wheel WRR and the left front wheel WFL. The second brake system 110a is composed of a hydraulic system connected to a disc brake mechanism provided on the left front wheel WFL and the right front wheel WFR, and the first brake system 110b is connected to the right rear wheel WRR and the left rear wheel WRL. A hydraulic system connected to the provided disc brake mechanism may be used. Further, the second brake system 110a includes a hydraulic system connected to a disc brake mechanism provided on the right front wheel WFR and the right rear wheel WRR on one side of the vehicle body, and the first brake system 110b includes the left front wheel WFL on the vehicle body side. And a hydraulic system connected to a disc brake mechanism provided on the left rear wheel WRL.

  Since the second brake system 110a and the first brake system 110b have the same structure, the corresponding parts in the second brake system 110a and the first brake system 110b are assigned the same reference numerals, and The description of the first brake system 110b will be added in parentheses with a focus on the description of the two brake system 110a.

The second brake system 110a (first brake system 110b) has a common pipe line (first common hydraulic pressure path 112 and second common hydraulic pressure path 114) for the wheel cylinders 32FR, 32RL (32RR, 32FL). Have. Among these, the first common hydraulic pressure path 112 is a supply path for supplying brake hydraulic pressure to the wheel cylinders 32FR, 32RL (32RR, 32FL).
The VSA device 18 includes a regulator valve 116 composed of a normally open type solenoid valve disposed between the introduction port 26a (26b) and the first common hydraulic pressure path 112, and the introduction port disposed in parallel with the regulator valve 116. Allow the brake fluid to flow from the 26a (26b) side to the first common hydraulic path 112 side (block the brake fluid from the first common hydraulic path 112 side to the introduction port 26a (26b) side) A first check valve 118; a first in-valve 120 including a normally open type solenoid valve disposed between the first common hydraulic path 112 and the first outlet port 28a (fourth outlet port 28d); The first common hydraulic pressure path 1 is arranged in parallel with the 1-in valve 120 from the first outlet port 28a (fourth outlet port 28d) side. A second check valve 122 that permits the flow of brake fluid to the second side (blocks the flow of brake fluid from the first common hydraulic pressure passage 112 side to the first outlet port 28a (fourth outlet port 28d) side); A second in-valve 124 composed of a normally open solenoid valve disposed between the first common hydraulic pressure path 112 and the second outlet port 28b (third outlet port 28c); and in parallel with the second inlet valve 124. The brake fluid is allowed to flow from the second outlet port 28b (third outlet port 28c) side to the first common hydraulic path 112 side (from the first common hydraulic path 112 side to the second outlet port 28b (second And 3rd check valve 126 for preventing the flow of brake fluid to the 3 outlet port 28c) side.

  The VSA device 18 of the present embodiment includes a pressure sensor P1 that measures the brake hydraulic pressure in the first common hydraulic pressure path 112, and a measurement signal measured by the pressure sensor P1 is input to the control unit 150. .

  The first in-valve 120 and the second in-valve 124 are opening / closing means for opening / closing a pipe line (first common hydraulic pressure path 112) for supplying brake hydraulic pressure to the wheel cylinders 32FR, 32RL, 32RR, 32FL. When the first in-valve 120 is closed, the supply of the brake hydraulic pressure from the first common hydraulic path 112 to the wheel cylinders 32FR and 32FL is shut off. Further, when the second in-valve 124 is closed, the supply of the brake hydraulic pressure from the first common hydraulic pressure path 112 to the wheel cylinders 32RR and 32RL is cut off.

  Further, the VSA device 18 includes a first out valve 128 including a normally closed solenoid valve disposed between the first outlet port 28a (fourth outlet port 28d) and the second common hydraulic pressure path 114, The second out valve 130 formed of a normally closed type solenoid valve disposed between the second outlet port 28b (third outlet port 28c) and the second common hydraulic pressure path 114, and connected to the second common hydraulic pressure path 114 Brake fluid from the second common hydraulic pressure path 114 side to the first common hydraulic pressure path 112 side disposed between the reservoir device 132 and the first common hydraulic pressure path 112 and the second common hydraulic pressure path 114 The fourth check valve 134 (which inhibits the flow of brake fluid from the first common hydraulic pressure path 112 side to the second common hydraulic pressure path 114 side) and the fourth check valve 34 and a first common hydraulic pressure path 112, and a pump 136 that supplies brake fluid from the second common hydraulic pressure path 114 side to the first common hydraulic pressure path 112 side, and provided before and after the pump 136. Suction valve 138 and discharge valve 140, a motor M for driving the pump 136, a normally closed type solenoid valve disposed between the second common hydraulic pressure path 114 and the introduction port 26a (26b). And a valve 142.

In the second brake system 110a, the second hydraulic pressure chamber 98a of the motor cylinder device 16 is output from the output port 24a of the motor cylinder device 16 to a pipe line (hydraulic pressure passage) close to the introduction port 26a. There is provided a pressure sensor Ph for measuring the brake fluid pressure controlled by. Measurement signals measured by the pressure sensors Pm, Pp, and Ph are input to the control unit 150. The VSA device 18 can also control ABS (anti-lock brake system) in addition to VSA control.
Further, instead of the VSA device 18, a configuration in which an ABS device having only an ABS function is connected may be employed.
The vehicle brake system 10 according to the present embodiment is basically configured as described above. Next, the operation and effect will be described.

  When the vehicle brake system 10 is functioning normally, the second shut-off valve 60a and the first shut-off valve 60b, which are normally open type solenoid valves, are energized to be closed, and the first shut-off valve, which is composed of a normally close type solenoid valve. The three shut-off valve 62 is excited and the valve is opened. Accordingly, since the second hydraulic system 70a and the first hydraulic system 70b are shut off by the second shut-off valve 60a and the first shut-off valve 60b, the hydraulic pressure generated in the master cylinder 34 of the input device 14 is disc brake mechanism. It is not transmitted to the wheel cylinders 32FR, 32RL, 32RR, 32FL of 30a to 30d.

  At this time, the hydraulic pressure generated in the first pressure chamber 56b of the master cylinder 34 is transmitted to the hydraulic pressure chamber 65 of the stroke simulator 64 via the branch hydraulic pressure path 58c and the third shut-off valve 62 in the valve open state. The The simulator piston 68 is displaced against the spring force of the first and second return springs 66a and 66b by the hydraulic pressure supplied to the hydraulic pressure chamber 65, so that the stroke of the brake pedal 12 is allowed, and the simulation is performed. A typical pedal reaction force is generated and applied to the brake pedal 12. As a result, it is possible to obtain a brake feeling that is comfortable for the driver.

  In such a system state, the control means 150 determines that the braking is being performed when detecting the depression of the brake pedal 12 by the driver, drives the electric motor 72 of the motor cylinder device 16 to energize the actuator mechanism 74, and 2 The second slave piston 88a and the first slave piston 88b are displaced in the direction of the arrow X1 in FIG. 1 against the spring force of the return spring 96a and the first return spring 96b. Due to the displacement of the second slave piston 88a and the first slave piston 88b, the brake fluid in the second fluid pressure chamber 98a and the first fluid pressure chamber 98b is pressurized so as to be balanced to generate a desired brake fluid pressure.

  Specifically, the control means 150 calculates a depression operation amount of the brake pedal 12 (hereinafter referred to as “brake operation amount” as appropriate) according to a measured value of the pedal stroke sensor St, and based on the brake operation amount, The target brake fluid pressure is set in consideration of the regenerative braking force, and the set brake fluid pressure is generated in the motor cylinder device 16.

The control means 150 of the present embodiment includes, for example, a microcomputer and peripheral devices that are configured by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., not shown. The control means 150 is configured to control the vehicle brake system 10 by executing a program stored in the ROM in advance by the CPU.
Moreover, the electrical signal in this embodiment is a control signal for controlling the electric power which drives the electric motor 72, and the electric motor 72, for example.

  Further, the operation amount measuring means for measuring the depression operation amount (brake operation amount) of the brake pedal 12 is not limited to the pedal stroke sensor St, and any sensor that can measure the depression operation amount of the brake pedal 12 may be used. . For example, the operation amount measuring means may be a pressure sensor Pm, and the hydraulic pressure measured by the pressure sensor Pm may be converted into a depression operation amount of the brake pedal 12, or the depression operation of the brake pedal 12 may be performed by a depression force sensor (not shown). It may be configured to measure the amount (brake operation amount).

  The brake hydraulic pressure in the second hydraulic pressure chamber 98a and the first hydraulic pressure chamber 98b in the motor cylinder device 16 is supplied to the disc brake mechanism 30a via the first and second in-valves 120 and 124 in the valve open state of the VSA device 18. To 30d wheel cylinders 32FR, 32RL, 32RR, 32FL, and when the wheel cylinders 32FR, 32RL, 32RR, 32FL are operated, each wheel (right front wheel WFR, left rear wheel WRL, right rear wheel WRR, left front wheel) WFL) is given a desired braking force.

  In other words, in the vehicle brake system 10 according to the present embodiment, when the motor cylinder device 16 that functions as a power hydraulic pressure source, the control means 150 that performs by-wire control, and the like are operable, the driver can use the brake pedal 12. The communication between the master cylinder 34 that generates hydraulic pressure by stepping on and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, and 32FL) that brake each wheel is connected to the second cutoff valve 60a and the first cutoff valve 60b. In this state, the so-called brake-by-wire type brake system in which the disc brake mechanisms 30a to 30d are operated with the brake fluid pressure generated by the motor cylinder device 16 becomes active.

  On the other hand, when the motor cylinder device 16 or the like becomes inoperable, the liquid generated in the master cylinder 34 with the second shut-off valve 60a and the first shut-off valve 60b opened and the third shut-off valve 62 closed respectively. The pressure is transmitted as brake fluid pressure to the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL), and the disc brake mechanisms 30a to 30d (wheel cylinders 32FR, 32RL, 32RR, 32FL) are operated. The so-called traditional hydraulic brake system becomes active.

  2A is a diagram showing a Hall sensor that detects the electrical angle of the electric motor, FIG. 2B is a diagram showing a detection signal output from the Hall sensor, and FIG. 2C is an electrical angle calculated by the control means. It is a figure which shows an actual electrical angle. In FIG. 2C, the vertical axis represents the electrical angle θ, and the horizontal axis represents time T. The solid line indicates the calculated value θcal of the electrical angle θ calculated by the control means, and the broken line indicates the actual value of the electrical angle θ (actual electrical angle θreal).

  In the vehicle brake system 10 configured as shown in FIG. 1, the electric motor 72 included in the motor cylinder device 16 includes three hall sensors 701U, 701V, and 701W as shown in FIG. ing. The detection signals of the respective hall sensors are input to the control means 150. The control means 150, based on the detection signals input from the respective hall sensors, as shown in FIG. Is calculated θcal. The control means 150 uses the calculated value θcal as the detected value of the electrical angle θ. Furthermore, the control means 150 calculates the movement amount (displacement amount of the ball screw shaft 80a) of the ball screw structure 80 (see FIG. 1) based on the detected value (calculated value θcal) of the electrical angle θ.

  The control means 150 controls the electric motor 72 based on the amount of displacement of the ball screw shaft 80a calculated from the electrical angle θ, and the brake hydraulic pressure corresponding to the amount of depression of the brake pedal 12 (brake operation amount) is controlled by the motor. It is generated in the cylinder device 16.

  As described above, the control unit 150 calculates the brake operation amount according to the measured value of the pedal stroke sensor St, and causes the motor cylinder device 16 to generate the brake hydraulic pressure that is set based on the brake operation amount. At this time, the control means 150 determines whether or not the second slave piston 88a and the first slave piston 88b are displaced by the amount of displacement corresponding to the brake fluid pressure to be generated (that is, whether or not the ball screw shaft 80a is displaced). Is determined by the electrical angle θ. Then, the control means 150 controls the electric motor 72 based on this determination.

As shown in FIG. 2A, three hall sensors 701U, 701V, and 701W are arranged at intervals of 120 degrees around a rotor 702 that rotates inside the electric motor 72 and rotates the output shaft 72b (see FIG. 1). Be placed. One of the rotors 702 divided by one plane including the axis is magnetized to the N pole, and the other is magnetized to the S pole. Hall sensors 701U, 701V, and 701W detect magnetic poles (changes between N poles and S poles) that change as the rotor 702 rotates, and output detection signals.
The magnetic pole detected by one Hall sensor changes every time the rotor 702 rotates 180 degrees. Therefore, as shown in FIG. 2B, the detection signal output by one Hall sensor is a rectangular wave whose output waveform changes every time the rotor 702 rotates 180 degrees.

When the hall sensors 701U, 701V, and 701W are arranged at intervals of 120 degrees, the output waveforms of the detection signals output from the hall sensors are 120 degrees out of phase.
As shown in FIG. 2B, the phase of the detection signal (Sig_V) output from the hall sensor 701V changes with a 120 degree delay relative to the change in the detection signal (Sig_U) output from the hall sensor 701U. Further, the phase of the detection signal (Sig_W) output from the hall sensor 701W is further delayed by 120 degrees.

Based on the combination of the output states (high level, low level) of the detection signals (Sig_U, Sig_V, Sig_W) output by the three hall sensors 701U, 701V, 701W, the control means 150 is stepped as shown in FIG. As shown by the solid line, the calculated value θcal of the electrical angle θ is calculated.
Note that the detection signals (Sig_U, Sig_V, Sig_W) shown in FIG. 2B are examples in which a high level indicates an N pole detection signal and a low level indicates an S pole detection signal. Is not limited.

  As shown in FIG. 2 (b), the three detection signals (Sig_U, Sig_V, Sig_W) change the output state (low level, high level) with a phase difference of 120 degrees, so that the three detection signals are output. The combination of states changes every 60 degrees. For this reason, while the rotor 702 rotates 60 degrees, the combination of the output states of the three detection signals does not change, and the control unit 150 cannot detect the change in the electrical angle θ. Hereinafter, the time point when the combination of the output states of the three detection signals changes is defined as a measurement point P. 2, 0 degrees, 60 degrees,..., 360 degrees shown in FIG. 2B are measurement points P at which the combinations of the output states of the three detection signals change.

  For example, as shown in FIGS. 2A and 2B, the moment when the Hall sensor 701U detects the “N pole” is set to a state where the electrical angle θ is 0 degree. At this time, the Hall sensor 701V detects “S pole”, and the Hall sensor 701W detects “N pole”. This state is continued until the Hall sensor 701W detects the “S pole”. That is, this state continues until the rotor 702 rotates 60 degrees. Therefore, the control means 150 sets the calculated value θcal of the electrical angle θ to 30 degrees at the moment when the Hall sensor 701U detects “N pole”, that is, at the time when the detection signal Sig_U becomes high level. Then, the calculated value θcal becomes 30 degrees while the rotor 702 rotates from 0 degrees to 60 degrees, that is, while the actual value of the electrical angle θ (actual electrical angle θreal) changes from 0 degrees to 60 degrees. The maximum error during this period is 30 degrees.

  As described above, the control unit 150 calculates the calculated value θcal so that the maximum error between the actual electrical angle θreal and the calculated value θcal is 30 degrees, and uses the calculated value θcal as the detected value of the electrical angle θ.

  The output state of the detection signals (Sig_U, Sig_V, Sig_W) changes according to the change in the magnetic pole of the rotor 702 detected by the hall sensors 701U, 701V, 701W. Therefore, the measurement point P is a point where the combination of magnetic poles detected by the hall sensors 701U, 701V, and 701W changes. Further, the control means 150 detects the electrical angle θ by calculating the calculated value θcal every time the combination of magnetic poles detected by the Hall sensors 701U, 701V, and 701W changes.

  When the actual electrical angle θreal changes as shown by the broken line in FIG. 2C, the calculated value θcal calculated by the control means 150 is stepped while generating an error of 30 degrees at the maximum, as shown by the solid line. Change. That is, the control means 150 calculates the detected value (calculated value θcal) of the electrical angle θ so that the maximum error is 30 degrees each time the combination of magnetic poles detected by the Hall sensors 701U, 701V, and 701W changes. .

  The control means 150 of the vehicle brake system 10 shown in FIG. 1 calculates the displacement amount of the ball screw shaft 80a based on the detected value (calculated value θcal) of the electric angle θ of the electric motor 72. Therefore, if an error occurs between the actual electrical angle θreal and the calculated value θcal, this error becomes a detection error of the electrical angle θ. When a detection error occurs in the detected value of the electrical angle θ by the control unit 150, an error occurs in the amount of displacement of the ball screw shaft 80a calculated by the control unit 150. When the control unit 150 controls the motor cylinder device 16, Accuracy is reduced.

  Therefore, the control unit 150 of the present embodiment estimates the electrical angle θ between 60 degrees (that is, between the measurement points P) in which the combination of the output states of the three detection signals (Sig_U, Sig_V, Sig_W) does not change. Thus, the detection error of the electrical angle θ is reduced.

  The control means 150 of the present embodiment calculates a calculated value θcal of the electrical angle θ based on the three detection signals at the measurement point P. The control means 150 uses the calculated value θcal as the detected value of the electrical angle θ at the measurement point P. Furthermore, the control means 150 estimates the electrical angle θ between the next measurement point P and the elapsed time from the previous measurement point P.

FIG. 3 is a diagram for explaining the estimation of the electrical angle. 4A is a diagram illustrating an estimated electrical angle line, and FIG. 4B is a diagram illustrating a state in which a change in the estimated value is suppressed within 60 degrees. FIG. 5 is a diagram showing a state where the actual electrical angle decreases with the passage of time. Note that the stair-like broken line in FIG. 3 indicates the calculated value θcal that is calculated conventionally by the control means 150.
As shown by the solid line in FIG. 3, when the actual electrical angle θreal changes and the actual electrical angle θreal becomes 0 degrees at time t2, the combination of the output states of the three detection signals (Sig_U, Sig_V, Sig_W) Changes. That is, the time t2 becomes the measurement point P. The control means 150 calculates the electrical angle θ at time t2 as 0 degrees, and uses this value (0 degrees) as a reference value at time t2. Further, the control means 150 calculates an elapsed time Δt12 from the time t1 to the time t2 of the measurement point P immediately before that. At time t1 (immediately before measurement point P), the control unit 150 sets the calculated value θcal (reference value) to “−60 degrees” which is 60 degrees smaller than 0 degrees.

If the control unit 150 does not reach the next measurement point P at the time ta after the time Δta has elapsed from the time t2, the control unit 150 estimates the electrical angle θ at the time ta (t2 + Δta) based on the following equation (1). θta is calculated. In the following equation (1), “0” in the first term on the right side indicates a reference value at time t2.
θta = 0 + Δta × (60 / Δt12) (1)

  When the actual electrical angle θreal becomes 60 degrees at the time t3, the time t3 becomes the measurement point P. Therefore, the control unit 150 sets the calculated value θcal to 60 based on the three detection signals (Sig_U, Sig_V, Sig_W) at the time t3. This value (60 degrees) is used as the reference value at time t3. Furthermore, the control means 150 calculates the elapsed time Δt23 from time t2 to time t3.

If the control unit 150 does not reach the next measurement point P at the time tb when the time Δtb has elapsed from the time t3, the control unit 150 estimates the electrical angle θ at the time tb (t3 + Δtb) based on the following equation (2). θtb is calculated. In the following equation (2), “60” in the first term on the right side indicates a reference value at time t3.
θtb = 60 + Δtb × (60 / Δt23) (2)

As described above, the control unit 150 sequentially calculates the estimated value of the electrical angle θ based on the elapsed time from the previous measurement point P to the next measurement point P. The dashed-dotted line shown in FIG. 3 shows the line (estimated electrical angle line L1) which connected the estimated value of electrical angle (theta).
Note that the control unit 150 may be configured to estimate the electrical angle θ based on a polynomial such as a quadratic function or a cubic function (or higher order) instead of the linear function as shown in the equation (2). Good.

  The elapsed time from the previous measurement point P to the next measurement point P corresponds to the rotational speed of the rotor 702 (see FIG. 2A). That is, the control means 150 calculates the estimated value of the electrical angle θ based on the elapsed time from the previous measurement point P to the next measurement point P, so that the electric power is indirectly based on the rotational speed of the rotor 702. The angle θ is estimated.

When the formulas (1) and (2) are represented by general formulas, the following formula (3) is obtained.
As shown in FIG. 4A, the time of a certain measurement point Pn (this is the current measurement point Pn) is “tn”, and the reference value of electric angle θ at time tn (value of calculated value θcal). ) Is “θnref”. In addition, the time of the previous measurement point Pm (this is the previous measurement point Pm) is “tm”, and the reference value (the value of the calculated value θcal) of the electrical angle θ at the measurement point Pm is “θmref”. And The reference value θnref of the measurement point Pn is advanced by 60 degrees from the reference value θmref of the measurement point Pm. That is, “θnref = θmref + 60”.
The control means 150 calculates an estimated value of the electrical angle θ at time tx when “Δtn” has elapsed from the time “tn” of the current measurement point Pn (this is referred to as “θx”) based on the following equation (3). To do.
θx = θnref + Δtn × (60 / (tn−tm)) (3)

  As shown in FIG. 4B, the electrical angle θ does not change by 60 degrees or more from the measurement point Pn to the next measurement point Po (time to). Therefore, when the estimated value θx calculated by the equation (3) is 60 degrees or more larger than the reference value θnref of the electrical angle θ at the measurement point Pn ((θx−θnref) ≧ 60), the control unit 150 has A value obtained by adding 60 degrees to the reference value θnref at the time point Pn is set as an estimated value θx of the electrical angle θ. The control means 150 sets “θx = θnref + 60”. Thereby, it is avoided that the estimated value θx becomes larger than the reference value θnref by more than 60 degrees. That is, the control unit 150 calculates the estimated value θx within a range that does not exceed the amount of change (60 degrees in the present embodiment) in which the electrical angle θ changes between the current measurement point Pn and the next measurement point Pm. To do.

As described above, the vehicle brake system 10 of the present embodiment shown in FIG. 1 includes three hall sensors provided with the electrical angle θ of the rotor 702 (see FIG. 2A) as shown in FIG. It is comprised so that it may detect by 701U, 701V, and 701W.
And the control means 150 is comprised so that the electrical angle (theta) of the range which the output state of the detection signal which each Hall sensor outputs does not change can be estimated. With this configuration, the detection value in a range where the output state of the detection signal output from each Hall sensor does not change is complemented, and the detection error when the control unit 150 detects the electrical angle θ of the rotor 702 is reduced. As a result, the accuracy with which the control means 150 calculates the amount of displacement of the ball screw shaft 80a is improved, and the accuracy with which the control means 150 controls the motor cylinder device 16 is improved.

When the rotation direction of the rotor 702 (see FIG. 2A) is switched (for example, when the rotation direction is changed from right rotation to left rotation) or when the rotation direction is switched during low-speed rotation, the actual electrical angle θreal The difference between the electrical angle θ and the estimated value θx may increase. In this case, rather than using the estimated value θx as the detected value of the electrical angle θ, the calculated value θcal calculated based on the three detection signals (Sig_U, Sig_V, Sig_W) is used as the detected value of the electrical angle θ. The detection error may be reduced.
Therefore, the control unit 150 stops calculating the estimated value θx when the rotation direction of the rotor 702 (see FIG. 2A) is switched. Then, the control unit 150 sets the calculated value θcal calculated based on the combination of the output states of the three detection signals (Sig_U, Sig_V, Sig_W) at this time as the detection value of the electrical angle θ. In this case, the control unit 150 may stop calculating the estimated value θx until the next measurement point P is reached.

Further, when the rotational speed of the rotor 702 becomes smaller than a predetermined value set in advance, the control means 150 (see FIG. 1) determines that the rotational direction of the rotor 702 may be switched, and the estimated value θx The calculation may be stopped and the detection value of the electrical angle θ may be calculated based on the combination of the output states of the three detection signals (Sig_U, Sig_V, Sig_W).
When the rotational speed of the rotor 702 becomes lower than a predetermined value set in advance, the rotor 702 may stop as it is. However, if the rotor 702 stops, the detection of the electrical angle θ becomes unnecessary. Therefore, when the control unit 150 calculates the electrical angle θ based on the combination of the output states of the three detection signals (Sig_U, Sig_V, Sig_W), the difference from the actual electrical angle θreal is larger than when the estimated value θx is calculated. Even if becomes larger, the effect is small.

<Modification>
The estimated values (θta, θtb, θx) represented by the equations (1) to (3) do not depend on the rotational direction of the rotor 702 (see FIG. 2A) of the electric motor 72 (that is, the rotor 702 The electric angle θ is always set to increase regardless of whether the rotation is left or right.
On the other hand, the electrical angle θ may be set to increase when the rotor 702 rotates in one rotational direction, and the electrical angle θ may decrease when rotated in the other rotational direction.

This case can be dealt with by including a term indicating the rotation direction of the rotor 702 in the equations (1) to (3). For example, the formula (3) may be transformed as the following formula (4).
θx = θnref + Δtn ×
((Θnref−θmref) / (tn−tm)) (4)

  As shown in FIG. 4A, when the reference value θnref at a time tn at a certain measurement point Pn is larger than the reference value θmref at the time tm of the immediately previous measurement point Pm, the sign of “θnref−θmref” is positive. Become. On the other hand, as shown in FIG. 5, when the actual electrical angle θreal decreases with time, the reference value θnref at the time tn of a certain measurement point Pn becomes smaller than the reference value θmref at the time tm of the immediately previous measurement point Pm. The sign of “θnref−θmref” is negative. Note that the amount of change from the reference value θmref of the measurement point Pm to the reference value θnref of the measurement point Pn is “60 degrees”, and the value (absolute value) of “θnref−θmref” is “60”.

  Further, when the sign of “θnref−θmref” is positive, the estimated value θx is larger than the reference value θnref of the measurement point Pn, and when the sign of “θnref−θmref” is negative, the estimated value θx is the measurement point. The value is smaller than the reference value θnref of Pn.

In the expression (4), the term “θnref−θmref” indicates the rotation direction of the rotor 702 (see FIG. 2A). That is, when “θnref−θmref” is positive, it indicates that the rotor 702 rotates in the direction in which the electrical angle θ increases, and when “θnref−θmref” is negative, the rotor in the direction in which the electrical angle θ decreases. 702 indicates that it rotates.
As described above, the expression for deriving the estimated value θx may include a term indicating the rotation direction of the rotor 702 (see FIG. 2A).

  With this configuration, even when the electrical angle θ is decreased depending on the rotation direction of the rotor 702 (see FIG. 2A), the control unit 150 (see FIG. 1) can measure the measurement point P and the measurement point P. Can be estimated. Then, by estimating the electrical angle θ between the measurement points P and P, the detection error when the control means 150 detects the electrical angle θ is reduced.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed in design without departing from the spirit of the invention.

In addition, the electric motor 72 (see FIG. 1) of the present embodiment includes three hall sensors 701U, 701V, and 701W (see FIG. 2A), but the electric motor 72 has four or more halls. A configuration including a sensor may be used.
If four Hall sensors are provided, the electrical angle θ is detected every 90 degrees. With such a configuration, the electrical angle θ between 90 degrees where the combination of the output states of the four detection signals does not change can be estimated.

10 Vehicle brake system (vehicle brake system)
72 Electric motor
701U, 701V, 701W Hall sensor 702 Rotor

Claims (10)

Hydraulic pressure generating means for driving the electric motor to generate brake hydraulic pressure;
A plurality of hall sensors for detecting an electrical angle of the electric motor;
A vehicle brake device comprising: control means for controlling the electric motor based on the electrical angle so that a brake fluid pressure is generated according to an operation amount of a driver operating a brake operation unit;
Each of the plurality of Hall sensors detects a magnetic pole of a rotor rotating in the electric motor, and outputs a detection signal whose output state changes according to the detected change of the magnetic pole,
The control means detects the electrical angle each time the combination of output states of the detection signals changes,
The electric brake angle is estimated between a change in the combination of output states and a next change in the combination of output states. The control means includes
Estimating the electrical angle until the next change in the output state combination based on the elapsed time from the change in the output state combination one time before the change in the current output state combination. The vehicle brake device according to claim 1. The control means includes
3. The electrical angle is detected based on the combination of the output states until the next combination of the output states is changed when the rotation direction of the rotor is switched. The brake device for vehicles as described. The control means includes
2. The electrical angle is estimated within a range that does not exceed a change amount in which the electrical angle changes from a change in the combination of the output states to a next change in the combination of the output states. The vehicle brake device according to any one of claims 3 to 4.   The vehicular brake device according to any one of claims 1 to 4, wherein the three hall sensors are arranged around the rotor at intervals of 120 degrees. The control means detects the electrical angle of the motor using detection signals output from a plurality of Hall sensors that detect the magnetic poles of the rotor rotating in the electric motor and the output state changes according to the detected change of the magnetic poles. An electrical angle detection method for
The control means is
Each time the combination of the output states of the detection signals output from the plurality of Hall sensors changes, the electrical angle is detected based on the combination of the output states,
The electrical angle detection method, wherein the electrical angle is estimated between a change in the combination of output states and a next change in the combination of output states. The control means is
The electrical angle until the next change in the output state combination is estimated based on the elapsed time from the change in the output state combination one time before the change in the current output state combination. The electrical angle detection method according to claim 6. The control means is
The said electrical angle is detected based on the combination of the said output state until the combination of the said output state changes next, when the rotation direction of the said rotor switches. Electrical angle detection method. The control means is
7. The electrical angle is estimated so as not to exceed a change amount in which the electrical angle changes from a change in the combination of output states to a next change in the combination of output states. The electrical angle detection method according to claim 8. The control means is
The electricity according to any one of claims 6 to 9, wherein the detection signals output from the three hall sensors arranged at intervals of 120 degrees around the rotor are used. Corner detection method.

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