JPWO2018185863A1 - DC motor controller - Google Patents

Abstract

An inexpensive DC motor control device having a function of detecting an absolute rotation angle of a rotary shaft is provided. A motor control device comprising a control unit and an MR sensor unit having a pair of MR sensors, and controlling power supplied via a brush to an armature fixed to a rotating shaft. Based on the output of the pair of MR sensors, incremental A phase and B phase signals accompanying the rotation of the rotary shaft and positioning information indicating a state in which the A phase and B phase output signals are in a specific relationship are generated. The control unit starts and operates the DC motor at a predetermined rotational speed in both forward and reverse directions according to the initialization drive signal, and positioning information from the MR sensor unit obtained by driving the DC motor and the Information on the relative origin position (Zα) of the MR sensor with respect to the rotation axis is acquired from the relationship of synchronization between the A-phase and B-phase output signals and the initialization drive signal. All data of phase, B phase, and relative origin position information is converted into absolute signal data and recorded in the EEPROM.

Description

  The present invention relates to a DC motor control device, and more particularly to a brushed DC motor control device suitable for servo control for operating a DC motor that drives a driven body at a target speed and a target position. is there.

  The DC motor with a brush has a relatively simple structure, can obtain a stable performance, and is inexpensive. Therefore, the brush DC motor is widely used as a drive source for devices constituting various control systems in various fields. For example, DC motors with brushes are used as motors for opening and closing of power seats, wiper arms, windows, trunk rooms, and back doors of automobiles, or as drive sources for opening and closing valves of engine intake and exhaust systems. Yes. For automobiles, a permanent magnet type brushed direct current motor having the same torque characteristics in both forward and reverse rotations is often used because of its small size and low cost.

In Patent Document 1, as a control technique of an electric motor that is a driving device for an automobile wiper arm, rotation of an armature shaft of a motor is detected by a rotation sensor such as a Hall element sensor, and a magnetoresistive element sensor (MR sensor) is used. An invention is disclosed in which the rotation angle of the output shaft, that is, the absolute position ( _Zo ) of the wiper arm is recognized to control the operation of the motor.

  Patent Document 2 discloses an invention that obtains information on arbitrary specific positions and torque fluctuation information of a three-phase permanent magnet motor based on signal values of three Hall elements and one GMR detector.

  Patent Document 3 extracts information on the rotational angle of the rotating body and information on changes in the rotational angle from the output values of the counter for a rotary encoder such as a brushless DC motor during forward rotation and reverse rotation. An invention for generating rotation angle information is disclosed.

JP 2013-001237 A JP2015-149800A Japanese Patent No. 5058334

In various driven members such as automobiles, in order to control the DC motor that drives the driven body, information such as the rotational speed, the determination of the rotational direction, and the rotational speed is required. By such information, for example, by performing slow start and slow stop, speed control, position control, and the like of various driven members of the automobile, it is possible to drive the automobile safely. Furthermore, in order to promote automatic operation control or automatic operation control, information such as high-precision rotation speed, determination of rotation direction, rotation speed, etc. is required, and not only information on the rotation angle of the rotation shaft of the motor. Information on the absolute angle or absolute position (absolute position: Z _o ) of the rotating shaft is also required.

In the invention described in Patent Document 1, in order to obtain information on the absolute position of multi-rotation, as a sensor, first detection means for detecting the phase angle of the motor and second detection means for detecting the rotation speed of the motor These two types of detection sensors are used. The invention of Patent Document 2 also employs two types of detection sensors. Such a conventional means for obtaining absolute position information employing two types of detection sensors has a complicated structure and is expensive. That is, the advantage of the brushed DC motor that the structure is relatively simple and stable performance is obtained and the price is low is lost.
In the invention described in Patent Document 3, position information corresponding to an absolute position is calculated using data of a set of sensor elements, and multi-rotation angle information of a rotating body is generated. However, there is no disclosure about obtaining the information corresponding to the absolute position with high accuracy with respect to the brushed DC motor.

  In addition, a DC motor that drives various driven members of an automobile uses an in-vehicle battery as a power source. The DC motor may stop due to various factors such as battery deterioration or power supply line disconnection, and the driving of the automobile may be stopped without the driven member returning to a normal state. In order to further improve the safety of the automobile, it is desirable that the vehicle can be safely restarted even after an abnormal stop accompanying the loss of the battery power. Patent Documents 1 to 3 do not disclose such consideration regarding restart after an abnormal stop.

  One object of the present invention is to control a brushed DC motor having a simple configuration using a pair of sensor elements and having a function of generating highly accurate position information corresponding to the origin position of the rotation axis of the motor. To provide an apparatus.

  Another object of the present invention is to provide a brushed direct current motor that has information on the rotational phase of the rotating shaft of the motor even after an abnormal stop accompanying the disappearance of the battery power supply, and can safely restart various driven members. It is to provide a control device.

  According to one aspect of the present invention, a control unit that generates and outputs a drive signal for a DC motor, and an MR sensor unit that detects rotation of a rotating shaft of the DC motor by a pair of MR sensors, In the motor control device that controls electric power supplied to the amateur fixed to the rotation shaft via the brush, the MR sensor unit is accompanied by rotation of the rotation shaft based on the outputs of the pair of MR sensors. Incremental A-phase and B-phase signals and positioning information indicating a state in which the output signals of the A-phase and B-phase are in a specific relationship are generated and output, and the control unit receives the direct current in response to the initialization drive signal. The motor is started and operated in both forward and reverse directions at a predetermined rotational speed, and the output signals of the A phase and B phase from the MR sensor unit obtained by driving the DC motor and the level Information on the relative origin position (Zα) of the MR sensor with respect to the rotation axis is acquired from the synchronization relationship between the decision information and the initialization drive signal, and the A phase, B phase, and relative origin position All data of information is converted into absolute signal data and recorded in the EEPROM.

  Thereby, it is possible to provide a control device for a brushed DC motor having a function of generating information on the relative origin position of the rotation shaft of the motor with a simple configuration using data of one set of sensor elements. . In addition, since the information of the relative origin position is recorded in the EEPROM, it is determined whether or not the driven member is abnormally stopped. Even when the driven member is abnormally stopped, a safe operation start is started at the next activation of the driven member. realizable.

  According to another aspect of the present invention, the control unit obtains the relative origin position (Zα) signal of the rotating shaft, which is obtained along with the start-up operation of the DC motor, and the A phase or the B phase. The output signal is used to generate a Z-phase width signal, and the address of the EEPROM is assigned to the Z-phase width signal data to obtain the absolute signal data.

  As a result, absolute signal data including the Z-phase width signal can be obtained with a simple configuration using data from one set of sensor elements, and can be used for controlling a brushed DC motor.

  According to the present invention, the information on the relative origin position of the rotating shaft obtained based on the output signals of the pair of MR sensors is recorded in the EEPROM as absolute position signal data. The position of the drive member can be controlled with extremely high accuracy.

  Further, according to the present invention, since the information on the relative origin position of the rotating shaft is recorded in the EEPROM as the absolute position signal data, it is determined whether or not the driven member is abnormally stopped. However, a safe start can be realized at the next startup.

It is a functional block diagram which shows the control apparatus of a DC motor based on 1st Example of this invention. It is a figure explaining an example of the magnet of MR sensor unit in the 1st example. It is a figure which shows the concept of the processing method of the output signal of MR sensor in 1st Example. It is a figure which shows an example of a structure of the processing circuit part of MR sensor unit in a 1st Example. It is a flowchart which shows the process at the time of starting of a control unit in a 1st Example. It is a flowchart which shows the detail of the self-initialization process in the process at the time of starting shown to FIG. 3A. It is a time chart explaining the process of the determination of a relative origin position based on rough positioning information in the self-initialization process. It is a figure which shows the output signal of MR sensor at the time of normal rotation command. It is a figure which shows the output signal of MR sensor at the time of reverse rotation command. It is a time chart explaining the process of the determination of a relative origin position based on the combination of rough and fine positioning information. It is a flowchart which shows the detail of the signal processing of the relative origin position of a control unit in a 1st Example. It is a figure explaining the signal processing of the relative origin position of FIG. 4 is a flowchart showing details of operations of a DC servo control unit and a PWM signal generation unit in the first embodiment. It is a figure which shows the structural example of the DC motor drive circuit in 1st Example. It is a figure which shows the relationship between a PWM signal and the rotation direction of a DC motor. It is a figure which shows an example of the open loop control of a DC motor using the data of EEPROM. It is a functional block diagram which shows the structure of the 2nd Example which applied this invention to the throttle-valve drive device and EGR valve drive device of a motor vehicle. It is a figure which shows the relationship between the absolute signal and the target opening degree of a throttle valve in a 2nd Example. It is a functional block diagram of the control apparatus of a DC motor based on 3rd Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a functional block diagram of a control device for a brushed DC motor based on a first embodiment of the present invention. The DC motor 100 is a brushed DC motor (hereinafter simply referred to as DC motor), and a permanent magnet 11 is fixed inside a motor housing 10 formed in a bottomed cylindrical shape. The rotating shaft 13 integral with the armature 12 is rotatably held by a pair of bearings 24 and 25 provided on the motor housing 10 and the end bracket (or shield cap) 18. From the viewpoint of cost reduction, for example, only one end of the rotating shaft 13 is held as a bearing by a ball bearing 25 and the other end is held by a flat bearing 24. A brush 16 held by a brush holder is in sliding contact with a commutator 17 fixed to the rotary shaft 13. A driving current is supplied from the battery 42 to the amateur 12 of the DC motor 100 via the ignition switch 43, the DC motor driving circuit 40, the power supply terminal 15, the brush 16, and the commutator 17. The amateur 12 rotates forward or backward depending on the direction and magnitude of the drive current supplied from the DC motor drive circuit 40. The other end of the rotating shaft 13 is provided with a pinion or the like constituting the speed reducer 14. The rotation of the rotating shaft 13 is decelerated by the speed reducer 14 and is directly or via a clutch, for example, a driven member 50. It is transmitted to the wiper arm of the car.

  An MR sensor unit 20 that outputs an incremental signal accompanying the rotation of the rotary shaft 13 is provided at one end of the rotary shaft 13. The MR sensor unit 20 includes a flat plate-shaped magnet 21 fixed to one end surface of the rotary shaft 13 and a pair of MR sensors (magnetic resistance) fixed in the motor housing at a position facing the magnet 21 so as to be separated from each other. An element sensor) 22 and a processing circuit unit 23 are provided. As the pair of MR sensors 22 (22A, 22B), for example, GMR, TMR, AMR or the like can be used. The pair of MR sensors 22 are arranged at predetermined intervals in the rotation direction of the rotary shaft 13 so that the phases of the output pulses are shifted from each other by a predetermined angle, for example, 90 degrees. The MR sensor 22 and the processing circuit unit 23 are provided on a single printed board. The printed circuit board of this MR sensor unit has an end bracket (or shield) in such a relationship that the MR sensor 22 faces the magnet 21 and the rotation centers of the MR sensor 22 and the magnet 21 coincide with the axis of the rotary shaft 13. Cap) is fixed to the inner surface of 18.

  The analog signals of the pair of MR sensors are quantized and converted into A-phase and B-phase digital signals that are quantized and divided into multiple by electrical angle interpolation processing in the processing circuit unit 23, and are cumulatively added by each pulse counter. The accumulated addition value is transmitted to the control unit 300 of the DC motor via the communication cable as incremental pulse data of the A-phase and B-phase signals. The number of pulses output from the MR sensor unit for each rotation of the DC motor 100 is arbitrarily set according to the resolution required for the control. When GMR is used as the element of the MR sensor, an output of, for example, 30000 pulses can be obtained per rotation of the rotation shaft.

  The DC motor control unit 300 is, for example, a dedicated ASIC (Application Specific Integrated Circuit) in which a plurality of necessary functions are integrated into a single chip in the form of a logic circuit, or an IC circuit using a general-purpose single-chip microcomputer. It is realized as a chip. Alternatively, it is realized as a part of the function of the host computer. Hereinafter, a specific configuration example using a general-purpose single-chip microcomputer will be described, but it goes without saying that a DC motor control device having the same function may be realized by a dedicated ASIC.

  The DC motor control unit 300 includes a communication control unit 310, a memory control unit 320, a self-initialization processing unit 341, a Z-phase signal generation unit 342, a Z-phase width signal generation unit 343, a relative origin position signal generation unit 344, a DC It has functions of a servo control unit 345, a PWM signal generation unit 346, and the like. A single-chip microcomputer integrates a CPU, memory, oscillation circuit, timer, I / O interface, serial I / F, etc. in one LSI, and by executing a program held in the memory on the CPU, The above functions of the DC motor control unit 300 are realized. The memory 330 includes a ROM 331, a RAM 332, at least one EEPROM 333, and the like, and is connected to the CPU via a bus 350. The ROM stores a program that is executed at power-on or reset, and constants that do not change during program execution. A flash memory may be employed as the ROM. The RAM stores program variables, external command values, multi-rotation / absolute position signal data, which will be described later, and the like. The RAM also stores the target position of the driven member 50 and the target speed of the DC motor (duty ratio of PWM control) set corresponding to this position. The EEPROM sequentially holds the A-phase and B-phase signals and the multi-rotation / absolute position signal.

In general, since the writing speed of the EEPROM is slower than that of other memories, the data of the absolute position signal and the like are once held in the RAM. Incremental A-phase / B-phase signal data held in the RAM is written (saved) to the EEPROM by an EEPROM application program or driver together with an address to be written to the EEPROM. Also, reading of these data and the like from the EEPROM to the RAM is processed by the application program and the driver using the address.
Needless to say, a signal other than the PWM signal may be used as a drive signal for driving the DC motor.

  The control unit 300 is connected to the battery 42 via a switch, for example, an ignition switch 43, and is an external command from an upper computer, for example, an in-vehicle ECU (Electric Control Unit) 500, or the output of the MR sensor 22. Based on input information such as digital values of the A-phase and B-phase signals, the DC motor is driven to switch the operation mode of the driven member 50, for example, the wiper arm. That is, in the DC motor control unit 300, a relative origin position signal and a Z-phase signal are generated based on the A-phase and B-phase signals, and a multi-rotation / absolute position signal is further generated. A part of the information of the control unit 300 is also transmitted to the ECU 500.

  Based on the command value stored in the memory 330 and various signals from the MR sensor unit 20, the control unit 300 calculates the rotational position of the DC motor that drives the wiper arm, and thus the rotational position of the wiper arm, and the wiper arm. Generates the information of the PWM signal for controlling the driving of the DC motor so as to reciprocately rotate up and down inversion positions on the wiping surface. Information on the DC motor drive PWM signal based on these signals is output from the DC motor control unit 300 to the DC motor drive control unit 41 via a serial communication line.

  The driven member 50 may be an object of open loop control by the control unit 300 or may be an object of closed loop control. In the case of closed-loop control, the rotational position and movement amount of the driven member 50 are detected by a sensor, and the information (A) is fed back to the control unit 300, and servo control of the DC motor is executed by the control unit 300. .

  The DC motor control unit 300 is mounted on a single printed circuit board 600 together with the DC motor drive control unit 41 and the DC motor drive circuit 40, for example, on the inner surface of the end bracket (or shield cap) 18 and MR. It can also be fixed at a position close to the sensor unit 20. In this case, the DC motor drive circuit 40 is connected to a power supply line between the power supply terminal 15 and the brush 16. Further, depending on the environment where the DC motor is installed, the printed circuit board 600 may be installed outside the DC motor. When a noise prevention circuit compliant with the EMC standard is installed in the brush holder or the like, it is desirable that the printed circuit board of the MR sensor unit or the printed circuit board 600 be connected to the battery on the battery side of the noise prevention circuit. . In the drawing, power supply lines such as the MR sensor unit 20 and the printed circuit board 600 are omitted.

  The communication control unit 310, the memory control unit 320, the self-initialization processing unit 341, the Z-phase signal generation unit 342, the Z-phase width signal generation unit 343, and the relative origin position signal generation unit illustrated in the form of functional blocks in FIG. Each function realized by executing programs such as 344, DC servo control unit 345, and PWM signal generation unit 346 is displayed as an example. The functions can be arbitrarily classified, and it is needless to say that the plurality of functions may be realized by a common program, or the specific function may be realized by a plurality of different programs or IC circuits.

FIG. 2A shows an example of the magnet of the MR sensor unit, and FIG. 2B shows the concept of the processing method of the output signal of the MR sensor.
A pair of MR sensors 22 arranged to face a flat magnet 21 fixed to one end face of the rotating shaft 13 detects a change in magnetic field resistance caused by switching between the N pole and the S pole. It is. In the present invention, since the transverse magnetic field unique to the MR sensor is used, the magnet 21 is not subjected to multi-site magnetization but N and S single-shot magnetization. When the plain bearing 24 is adopted as one of the bearings of the DC motor, the rotary shaft 13 may move in the axial direction by a maximum value of, for example, about 0.2 mm in accordance with the forward / reverse switching of the DC motor. When a Hall element that uses a longitudinal magnetic field is employed as a sensor, such a movement of the rotating shaft accompanying switching between normal rotation and reverse rotation has a great influence on the sensor output. In the present invention, an MR sensor facing the one end surface of the rotating shaft 13 is disposed and a transverse magnetic field unique to the MR sensor is used. Therefore, even if the rotating shaft 13 to which the magnet 21 is fixed moves slightly in the axial direction, the output of the MR sensor 22 is not affected.
The magnet 21 is composed of a thin film of an alloy mainly composed of a Si or glass substrate and a ferromagnetic metal such as Ni or Fe formed thereon. The pair of magnetoresistive elements constituting the MR sensor 22 are arranged at a predetermined interval in the rotation direction of the rotary shaft 13 so that the phases of the output pulse signals are shifted from each other by 90 degrees. The pair of magnetoresistive elements are connected in series, and a voltage Vcc is applied to both ends thereof, and a voltage signal representing the potential at the connection point between the two elements is the output of the MR sensor 22.

  The MR sensor 22 is provided so that the characteristic in which the electric resistance value varies with the direction of the acting magnetic field. Therefore, when the magnet 21 rotates by an angle Θ and the direction of the magnetic field acting on each MR sensor rotates, the electrical resistance value of the MR sensor, in other words, the voltage of the output signal of the MR sensor 22 fluctuates accordingly. Corresponding to one rotation of the rotary shaft 13, a pulse signal for one cycle is output for each of the SIN wave and the COS wave at 360 degrees.

  FIG. 2C shows an example of the processing circuit unit 23 of the MR sensor unit 20. The processing circuit unit 23 includes an AD converter 231, an axis deviation correction processing unit 232, a memory 233 such as a RAM, an arctangent calculation processing unit 234, a pulse counter 235, an incremental A phase / B phase signal generation unit 236, and a positioning information generation unit. 237, a parallel / serial conversion unit 238, and a serial communication unit 239. The processing circuit unit 23 is realized, for example, by executing a program on a microcomputer with a memory.

  In the processing circuit unit 23, the analog signal output from the pair of MR sensors 22A and 22B is converted into a digital signal by the AD converter 231, the arc tangent calculation unit 234 performs arc tangent calculation, and the pulse counter 235 adds them. The accumulated addition value is generated as an incremental A-phase signal and B-phase signal (hereinafter referred to as A-phase / B-phase signal) by the incremental A-phase / B-phase signal generation unit 236 and held in the memory 233.

In addition, the positioning information generation unit 237 uses the analog signals of the MR sensors 22A and 22B to display information corresponding to a specific angle Θ as a result of the arctangent calculation shown in the right diagram of FIG. Is generated as “positioning information (Sn)” for determining the position of the original origin, and is stored in the memory 233. For example, both the horizontal axis and the horizontal axis in the right diagram in FIG. 2B corresponding to the rotation angle 0 of the rotation axis are 0 degrees, in other words, SIN, which corresponds to the rising time corresponding to 0 degrees of the A-phase signal. The 0-0 point of the COS waveform is used as positioning information (Sn). In this case, only one positioning information (Sn) is generated for each rotation of the rotating shaft 13.
The rotation angle Θ for generating the positioning information (Sn) may be an arbitrary value. That is, the positioning information (Sn) is generated at a position where the value of the SIN waveform and the value of the COS waveform have a specific relationship set in advance.
Further, a plurality of positioning information (Sn) is generated for each rotation of the rotary shaft 13, in other words, for each of a plurality of positions where the value of the SIN waveform and the value of the COS waveform are in a specific relationship set in advance. May be. Alternatively, different types of signals having different resolutions, for example, a coarse signal of about 1 to 2 times per rotation and a dense signal of about several tens of times per rotation may be combined. Alternatively, different types of signals may be generated by combining the A-phase signal and the B-phase signal.
In the present invention, such a position where the value of the A phase and B phase signals, in other words, the value of the SIN waveform and the value of the COS waveform are in a specific relationship set in advance is expressed as “A phase, B phase. Is defined as a position indicating a state in which the output signal is in a specific relationship.

  Note that the A-phase and B-phase signals (and positioning information) obtained from the pair of MR sensors 22A and 22B are errors (mainly axis misalignment errors) due to production errors, installation errors, temperature effects, etc. of each sensor. ) May be included. That is, the A-phase / B-phase signal obtained as a result of the arctangent calculation should be positioned on a straight line in proportion to the rotation angle Θ of the rotating shaft 13. However, due to errors such as axial misalignment, repeated distortion may be included every 360 degrees or every 90 degrees of phase difference between a pair of MR sensors. The axis deviation correction processing unit 232 extracts the rotation center of a pair of MR sensors based on data for at least one rotation of the rotating shaft 13 and detects the presence or absence of distortions such as A-phase and B-phase signals with respect to the rotation angle Θ. If there is distortion, the correction process is performed.

  Further, the A-phase / B-phase signal generated by the parallel transmission processing and the positioning information (Sn) are transmitted by the parallel-serial conversion unit 238 for transmission data (BUS signal for serial transmission conforming to the serial transmission communication standard). And the BUS signal is transmitted from the serial communication unit 239 to the control unit 300 of the DC motor via one transmission path.

  An up / down counter is adopted as the pulse counter 235 of the MR sensor unit, and A and B phase signals are generated by adding information on the forward / reverse rotation direction of the rotating shaft 13 to the cumulative addition / subtraction value of the pulse, and positioning information At the same time, it may be transmitted to the control unit 300 of the DC motor. In the present invention, count information with information on the rotation direction by such an up / down counter is also handled as a cumulative addition value.

Table 1 shows an example of various information generated by the MR sensor unit 20, recorded in the memory 233, and transmitted to the control unit 300.

  Next, FIG. 3A is a flowchart showing processing at the time of activation of the control unit in the first embodiment of the present invention. First, immediately after the power is turned on, the DC motor control unit 300 checks whether or not self-initialization has been completed (S301). If not, the process proceeds to the self-initialization processing mode (S302).

FIG. 3B shows details of the self-initialization process (S302) of the control unit 300 in the startup process. In the self-initialization process, EEPROM data is initialized (S311), an initialization drive signal for self-initialization, for example, a PWM signal (± N rotation) is generated and output to the DC servo control unit 345 (S312), The signal generation unit 346 generates a drive signal, and drives the DC motor by the PWM signal.
The detection of the A phase and B phase signals immediately after the power is turned on is performed by rotating the DC motor in both forward and reverse directions based on the PWM signal and causing the magnet 21 on the rotating shaft 13 to move relative to the MR sensor 22. Performed (S313).
The initialization drive signal is a substitute for the DC servo control signal of the DC motor. Even if the target DC motor is originally closed-loop controlled, first, in the self-initialization process, the DC motor is driven by the initialization drive signal in the open control state.

When the DC motor 100 is driven in the normal direction and the reverse direction with a PWM signal as a motor drive signal, the MR sensor unit 20 outputs an A phase signal, a B phase signal corresponding to the command value (motor drive signal), and positioning information (Sn ) Is obtained.
FIG. 4A shows the relationship between the PWM signal and the output of the MR sensor during the self-initialization process. FIG. 4B is a diagram showing an output signal (A phase, B phase) of the MR sensor when a forward rotation command is used as a PWM signal, and FIG. 4C is a reverse rotation command as a PWM signal. The phase shift direction is reversed according to the rotation direction of the rotary shaft 13.
Here, it is assumed that the positioning information (Sn) is generated at 0-0 points of the SIN and COS waveforms corresponding to the rising time corresponding to 0 degree of the A phase signal. In this case, the rotating shaft needs to pass through the origin position while the DC motor is rotating forward.
Therefore, as shown in the lowermost stage of FIG. 4A, the DC motor is started and rotated forward from −2.5 to +3.5 by the initialization drive signal (PWM signal). As shown in the uppermost part of FIG. 4A, when the direct current motor exceeds the respective rotations of −2, −1, 0, +1, +2, and +3 while rotating forward, the result of the arc tangent calculation is 0−0. It becomes a point. That is, at each time point, the rising edge of the digital value corresponding to 0 degree of the A phase signal is obtained. In this way, positioning information (S1) to (S6) corresponding to each time point is output.
The control unit 300 acquires the information described in Table 1 from the MR sensor unit 20 during the self-initialization process.

  The obtained A-phase and B-phase signals are compared with the command value of the self-initialization process, and whether or not the accumulated addition value is normal, that is, the accumulated addition value of the A-phase and B-phase signals becomes the command value of the PWM signal. Correspondingly, it is determined whether or not the response state of the DC motor or MR sensor is normal (S314). When it is determined that there is an abnormality in the correspondence relationship, output correction processing such as correction of temperature characteristics of the MR sensor is separately performed so that the command value corresponds to the cumulative addition value of the A-phase and B-phase signals. Performed (S315). Note that if the output correction process (S315) is not performed normally even if it is performed a plurality of times, another cause such as an abnormality in the EEPROM itself may be considered, and an error display to that effect is displayed.

If it is determined that the MR sensor is normal, or if correction processing has been performed, the self-initialization processing next performs absolute conversion of information acquired from the MR sensor unit 20 (S316). That is, for recording to the EEPROM, a write address is assigned (addressed) to each data of the A phase and B phase signals. Thus, in order to make an absolute signal, the address of the EEPROM corresponding to the accumulated addition value is assigned to each of the A-phase and B-phase signals, which are time-series output values of the MR sensor unit, to obtain an absolute signal. . Further, the time point of the positioning information (S4) synchronized with the 0 value of the motor drive signal is set as a temporary origin position (Zβ). Since the temporary origin position (Zβ) is based only on the output of the MR sensor, it is not clear whether it corresponds exactly to the absolute origin position (absolute position Z _o ) of the MR sensor. . It can be said that this is a provisional absolute signal suitable for giving angle information with a certain degree of accuracy to the rotating shaft 13.

  Then, temporary absolute signal data associated with the temporary origin position (Zβ) is recorded in the EEPROM via the RAM (S317). A table of simple absolute values as shown in Table 2, for example, is provided by assigning addresses to the data of the cumulative addition value of the A-phase and B-phase signals and provisional absolute signal data and recording them in the EEPROM. Can be created.

Next, the process proceeds to a relative origin position extraction mode (S318) in which the relative origin position Zα corresponding to the absolute position (Absolute) of the MR sensor 22 with respect to the rotation axis 13 is extracted. The absolute origin position (Z _o ) of the MR sensor indicates a state in which the output of the MR sensor 22A is zero with respect to a specific position of the magnet 21 on the rotating shaft 13. In the present invention, instead of directly detecting the absolute origin position (Z _o ), the relative origin position Zα corresponding to the absolute origin position is indirectly extracted.
In the relative origin position extraction mode (S318), based on the above definition, as shown in FIG. 4A, positioning information (S1) to (S6) obtained from the results of arctangent calculation of the A phase and B phase signals of the MR sensor. ) In which the ON duty of the PWM signal is synchronized with zero. In the example shown in the figure, the position of the positioning information (S4) is synchronized with the rise time of the A-phase pulse, and the relative origin position (Zα) of the MR sensor. And In this way, it is possible to determine a relative origin position with considerably high accuracy with respect to the absolute position (Absolute).
Further, by using time information such as the transmission timing of the command value (PWM signal) of the initialization drive signal and the reception timing of the A-phase and B-phase signals and positioning information, the relative origin position Zα can be set with higher accuracy. A decision can be made.
In this way, highly accurate “MR sensor relative origin position (Zα)” data is obtained based on the high-resolution A-phase and B-phase signals and positioning information corresponding to the initialization drive signal.

  Returning to FIG. 3B, the Z-phase signal generator 342 next sets the Z-phase signal and the width of the Z layer (S319). First, a Z phase signal is set. Here, based on the relative origin position Zα obtained in the previous step, the Z layer signal is set for the incremental A phase / B phase signal. That is, Z phase signals (Z0, Z1, Z2,-,-, Zn) are set in synchronization with each rising edge of the A phase digital output at 360 degree intervals with respect to the cumulative addition value of the A phase and B phase signals. To do. For example, Z0 represents that the rotation shaft 13 is less than one rotation, and Z1 represents that the rotation shaft 13 is one rotation or more and less than two rotations. The Z-phase signal may be synchronized with each rising edge of the B-phase digital output.

  The cumulative addition value of the A-phase / B-phase signal from which the Z-phase signal was obtained is then converted into a cumulative addition value for each rotation (every 360 degrees) of the rotating shaft 13, and this is combined with this Z-phase signal. The address of the EEPROM is given to become multi-rotation absolute signal data. The data of the multi-rotation absolute signal is recorded in the EEPROM in a table format as shown in Table 3, for example. The A-phase and B-phase signal data shown in Table 3 is a high-accuracy absolute value table including information on the rotation speed and rotation angle (phase) regarding the rotation axis, for example. This table can be used as control information for the DC motor.

Next, the width of the Z layer starting from the relative origin position Zα is determined.
First, as shown in FIG. 4B, in synchronization with the rising of the first A signal of each Z-phase signal (Z0, Z1, Z2,-,-, Zn), "Z Determine the phase width (1) "signal. Further, in synchronization with the rise of the A signal, a signal of “Z phase width (2)” having a width of one period of the A signal is determined. The signals of “Z-phase width (1)” and “Z-phase width (2)” are signals that repeat at intervals of 360 degrees.
Similarly, as shown in FIG. 4C, it has a width of 1/2 cycle of the B signal in synchronization with the rise of the first B signal of each Z-phase signal (Z0, Z1, Z2,-,-, Zn). The signal of “Z phase width (3)” is determined. Further, in synchronization with the rise of the B signal, a signal of “Z width (4)” having a width of one period of the B signal is determined. “Z-phase width (3)” and “Z-phase width (4)” are also signals repeated at intervals of 360 degrees. The period of “Z phase width” and the number of “Z phase width” can be arbitrarily set. An EEPROM address is assigned to the A-phase, B-phase signal, and Z-phase data, and the data is recorded in the EEPROM as shown in Table 4, for example.

  Next, all the A-phase and B-phase signals obtained from the MR sensor unit are related to the relative origin position Zα, Z-phase signal, and “Z-phase width”, are assigned the address of the EEPROM, and are rotated. It is converted into a multi-rotation / absolute position signal representing the relative origin position of the shaft 13 (S320).

And, as a result of the self-initialization process, all data of the A phase, B phase, relative origin position (Zα), Z phase position, and Z phase width signals at the time of startup are passed through the RAM. Recorded in the EEPROM (S321). That is, the tables shown in Table 2, Table 3, and Table 4 are linked to each other so that they can be referred to each other by an EEPROM address or the like and recorded in the EEPROM.
For example, each data in Table 4 can be used as a table that gives absolute information on the position and angle of the rotating shaft. Each of the “Z-phase width (1)” to “Z-phase width (4)” is used to generate various control signals for the DC motor, such as a PWM signal.

Returning to FIG. 3A, if the self-initialization process has been completed, the process proceeds to the abnormal termination determination mode. In this mode, the absolute position signal data of multiple revolutions is read from the EEPROM via the RAM (S303). Based on the read absolute position signal data, is the previous DC motor operation completed normally? Then, it is determined whether the process has ended in an abnormal state (S304). If the operation is normally completed, the absolute position signal data of the EEPROM should correspond to the position of the absolute value 0 of the rotating shaft when the DC motor is started, that is, the relative origin position Zα. If the data of the absolute position signal is away from the position Zα, that is, the absolute value 0, it is determined that the abnormal end has occurred. In the case of abnormal termination, error information is transmitted to the host ECU (S305), and a return process for resuming operation of the driven member 50 is performed from the ECU side.
If there is no abnormality, the control unit 300 of the DC motor shifts to a normal operation processing mode (S306).

  The positioning information (Sn) is used only in the self-initialization process and is essentially unnecessary in the normal operation process mode. Therefore, when the self-initialization process is completed, the recording of the positioning information (Sn) data received from the MR sensor unit into the memory may be stopped. Conversely, the positioning information (Sn) may be corrected by the relative origin position Zα and used for controlling the motor as one of angle information in the normal operation processing mode such as a Z-phase signal.

  In addition, DC motors with brushes for automobiles include, for example, power sources such as power seats, electronic turbochargers, wiper arms and the like that rotate several tens to several hundreds of revolutions (rpm) in both forward and reverse directions. Some DC motors such as a throttle valve drive source can be driven only within one or two revolutions in both forward and reverse directions. In such a DC motor with a narrow rotation range, it is required to accurately determine the relative origin position Zα in a narrower angle range during the self-initialization process. In order to meet such a requirement, the origin position can also be determined based on a combination of fine or coarse and fine positioning information.

  FIG. 4D is a time chart for explaining the process of determining the relative origin position during the self-initialization process based on a combination of coarse and fine positioning information. In the example of FIG. 4D, as positioning information output from the placement information generation unit 237 of the MR sensor unit, coarse positioning information once for every 180 degrees of rotation of the rotating shaft and 1 for every 6 degrees of rotation of the rotating shaft. And the dense positioning information of the times are output. First, in the rough positioning information (-, S20,-, S45,-,), the on-duty of the PWM signal is synchronized with zero. In this example, the position of the positioning information (S40) is changed to the A-phase pulse. A relative origin position (Zα) of the MR sensor that is synchronized with the rising point is provisionally determined. Next, in this example, dense positioning information (-, S388,-,-, S418,-,) is adopted in the vicinity of the provisional position (S40), and the on-duty of the PWM signal is synchronized with zero in the vicinity. Then, the position of the positioning information (S406) is formally determined as the relative origin position (Zα) of the MR sensor. In this way, it is possible to determine a relative origin position with considerably high accuracy that may include an error of about ± 6 degrees with respect to the absolute position (Absolute).

FIG. 5 is a flowchart showing details of relative origin position signal processing in the normal operation processing mode.
In the normal operation processing mode, the direct current motor control unit 300 transmits the relative origin Zα and Z-phase signals (Z0, Z1, Z2, etc.) as shown in Tables 3 and 4 from the EEPROM of the memory via the RAM. -,-, Zn) are acquired (S501), and the signal of the width of the Z phase is also acquired (S502). Further, the A-phase / B-phase signal from the MR sensor unit is acquired via the RAM (S503), and the EEPROM address is assigned based on the incremental cumulative addition value, and the A-phase for each rotation.・ Absolute the B phase signal and record it in the RAM (S504). Furthermore, a multi-rotation absolute position signal including information on the rotational speed and rotation angle of the DC motor is generated from the A-phase / B-phase signal and the Z-phase signal, and tables corresponding to Tables 3 and 4 are generated. And recorded in the RAM (S505).

FIG. 6 is a diagram for explaining the signal processing of the relative origin position. In this figure, in particular, examples of the A phase, B phase signals, and Z position signals (Z0, Z1,-, Zn) are shown. The Z position signal (Z0, Z1,-, Zn) is incremented or decremented for each rotation of the motor rotation shaft in accordance with the forward or reverse rotation of the DC motor rotation shaft, and the relative origin position (Zα) Information on the rotation angle of the rotation axis based on the A phase and B phase signals is also incremented and decremented.
As the multi-rotation absolute position signal, for example, Z1-A phase-20435 corresponding to the position P1 of one rotation is shown in the lower example of FIG. These pieces of information are generated by the MR sensor unit 20 as information representing the current position of the rotating shaft of the DC motor with respect to the relative origin position (Zα), transmitted to the control unit 300, and sequentially via the RAM. For example, it is recorded in the EEPROM as a table as shown in Tables 3 and 4 (S506). This is repeated until the operation processing mode ends (S507), and ends when the operation ends.

Next, operations of the DC servo control unit 345 and the PWM signal generation unit 346 in the normal operation processing mode will be described with reference to FIGS. 1 and 7.
The DC servo control unit 345 is based on the rotational speed and rotational angle signals and the multi-rotation / absolute position signals recorded in the EEPROM in the form of tables such as Tables 3 and 4, and the DC motor 100. The current rotation angle of the rotary shaft 13 and the current relative origin position of the driven member 50 are recognized. The DC servo control unit 345 calculates a speed command value from the current position of the driven member 50 to the target position based on these pieces of information. The PWM signal generation unit 346 receives the output of the DC servo control unit 345, generates a PWM signal for controlling the rotation of the DC motor 100, and outputs the PWM signal to the DC motor drive control unit 41.

FIG. 7 is a flowchart showing details of operations of the DC servo control unit 345 and the PWM signal generation unit 346 in the normal operation processing mode.
First, the DC servo control unit 345 acquires, from the memory 330 such as a RAM, each target position and target speed based on a preset DC motor operation pattern as a command value (S601). In the memory, as a target speed corresponding to the operation pattern of the DC motor set corresponding to each target position of the wiper arm blade which is a driven member, data of a motor drive signal based on PID control, for example, PWM control signal data Is stored. As an example of an operation pattern including the position of each target, for example, the wiper motor is an acceleration region from the reverse position of the wiper arm blade to the end of acceleration, a constant speed region from the end of acceleration to the start of braking, and a deceleration region from the start of braking to the reverse position. It has become. The DC motor is PWM controlled according to such a predetermined operation pattern.

The speed (PWM) signal generation unit 346 acquires a multi-rotation absolute position signal (S602), and calculates a difference value from the command value (S603). Based on the calculation result, the speed (PWM) signal generation unit 346 determines the presence or absence of “deviation” (S604), and if the difference exceeds the allowable value, determines that there is “deviation”. If this is the case (S605, S606), it is determined that there is an error including deviation in the encoder (MR sensor unit 20), abnormal information is transmitted to the ECU 500 (S607), and the process is terminated. Note that even when there is an abnormality in the EEPROM itself instead of the encoder, it can be checked at this point.
If there is no “deviation” in the deviation determination (S604), a PWM signal based on PID control is generated (S608) and output to the DC motor drive control unit 41 (S609). Then, a multi-rotation / absolute position signal based on the A-phase / B-phase signal from the MR sensor unit 20 is acquired (S610), and a difference deviation amount between the PWM signal and the multi-rotation / absolute position signal is calculated (S611). Next, the presence / absence of deviation is determined (S612). If the difference deviation exceeds the allowable value twice consecutively (S613, S614), it is determined that the DC motor is abnormal, and the ECU 500 is connected to the DC. Motor abnormality information is transmitted (S615), and the process is terminated.
If there is no “deviation” in the difference deviation amount determination (S612), a new PWM signal is generated (S608), and the same processing is repeated thereafter.

FIG. 8A is a diagram illustrating a configuration example of the DC motor driving circuit 40. The DC motor drive circuit 40 is an H bridge circuit in which four switching elements SW1 to SW4 made of transistors are assembled in an H shape. The PWM signal generated by the DC motor drive control unit 41 is input to the bases of the switching elements SW1 to SW4.
In FIG. 8A, the first switching element SW1 has one end connected to one brush 16A of the DC motor and the other end connected to a DC power supply (Vcc). The second switching element SW2 has one end connected to the other brush 16B of the DC motor and the other end connected to a DC power supply (Vcc). The third switching element SW3 has one end connected to one brush 16A of the DC motor and the other end grounded. The fourth switching element SW4 has one end connected to the other brush 16B of the DC motor and the other end grounded.

  When the ignition switch 43 is turned on in this state, the DC motor control unit 300 acquires a multi-rotation absolute position signal from the EEPROM of the memory, and recognizes the relative origin position of the wiper arm at the previous stop. When the relative origin position corresponds to an abnormal stop away from the relative origin position Zα, the wiper arm is driven by the DC motor until the engine is started by the ignition switch 43 to return to the normal state. Is made.

  When the wiper switch is turned on when starting in the normal state, the DC motor control unit 300 acquires a command value based on a predetermined operation pattern of the wiper arm, and drives the DC motor 100 by PWM control. To do. When the first and fourth switching elements SW1 and SW4 are turned on in a normal state, the brush 16A is connected to the battery via SW1, the brush 16B is grounded via SW4, and a direct current is applied between the brushes 16A and 16B. Current flows and the DC motor rotates forward. When the second and third switching elements SW2 and SW3 are turned on, the brush 16B is connected to the battery via SW2, and the brush 16A is grounded via SW3, and during forward rotation between the brushes 16B and 16A. Reverse DC current flows and the DC motor reverses.

When the DC motor 100 rotates, the DC motor control unit 300 recognizes the rotational speed / rotation direction and relative origin position of the DC motor based on the A-phase / B-phase signals from the MR sensor unit 20, and the recognized rotation. The speed, rotation direction, relative origin position, and command value are compared, and DC motor operation control is performed by PWM control.
In this way, the DC motor control unit 300 continues to drive the DC motor while recognizing the operation state of the wiper arm sequentially based on the A-phase / B-phase signals from the MR sensor unit 20. Thereby, the wiper arm performs a swinging wiping operation based on the operation pattern in a predetermined angle range.

The rotational speed of the DC motor can be arbitrarily controlled by the duty ratio during the PWM signal ON period. FIG. 8B is a diagram illustrating an example of the relationship between the PWM signal and the rotation direction of the DC motor. The direct-current motor can be forward regeneratively braked or reversely regeneratively braked at an arbitrary speed by controlling the combination of the on / off periods of the switching elements SW1 to SW4 and the duty ratio of the on period.
FIG. 8C shows an example of open loop control of a DC motor using EEPROM data. The DC motor is driven accurately and quickly from the current position P _n to the target position P _{n + 1} by the information on the multiple rotation / absolute position signal of the EEPROM and the rotation command combining the PID control and the PWM control.

  In this way, the DC motor control unit 300 continues to drive the DC motor while recognizing the operation state of the wiper arm sequentially based on the A-phase / B-phase signals from the MR sensor unit 20. Thereby, the wiper arm performs a swinging wiping operation based on the operation pattern in a predetermined angle range.

  According to one embodiment of the present invention, the rotating shaft is driven based on the information of the multi-rotation / relative origin position signal generated based on the output signals of the pair of MR sensors. It is possible to provide a DC motor control apparatus that can control the position of the motor with high accuracy and that is inexpensive with a simple configuration. Further, a multi-rotation / absolute position signal generated based on the relative origin position using the output signal of the MR sensor unit having a pair of MR sensors is recorded in the EEPROM. Therefore, the presence or absence of an abnormal stop of the driven member is determined, and a safe start of operation can be realized at the next startup even in the case of an abnormal stop of multiple rotations.

  Next, a second embodiment of the present invention will be described. FIG. 9 is a configuration diagram of a second embodiment in which the present invention is applied to a throttle valve driving device and an EGR valve driving device of an automobile. This embodiment includes an automobile throttle valve drive and an EGR valve drive, each driven by a brushed DC motor.

  In this embodiment, each function of the control unit 300A is incorporated in an in-vehicle engine control ECU 700, unlike the control unit 300 of FIG. The function of the DC motor drive control unit 41 is also incorporated in the in-vehicle ECU 700. The power circuits 40A and 40B correspond to the DC motor drive circuit 40 of FIG. The functions of the control unit 300A in FIG. 9, the power circuits 40A and 40B, the functions of the DC motor drive control unit 41, and the configurations of the DC motors 100A and 100B are the same as the functions of the control unit 300 in FIG. 40, the functions of the DC motor drive control unit 41 and the DC motor 100 are the same, and the description thereof is omitted.

The rotation range of a direct current motor that drives a throttle valve or EGR valve of an automobile is usually within ± 1 to 2 rotations. Therefore, higher accuracy is required for the information on the origin position.
In particular, when the rotation angle of the rotating shaft of the DC motor that drives the driven member is less than 360 degrees, within one rotation of the rotating shaft based on the position of the relative origin and the A-phase and B-phase signals. The absolute position signal is generated and recorded in the EEPROM, and the DC motor is driven using this information. In this case, the relative origin position signal 344 functions as an absolute position signal generation function unit for one rotation, and employs a high-resolution signal as positioning information or a different type of signal with different resolution as described in FIG. 4D. Thus, it is desirable to determine the relative origin position during the self-initialization process.

  The control unit 300A drives the brushed DC motor 100A by the power circuit 40 based on input information such as an external command from the ECU 700 or the like and digital values of the A phase and B phase signals output from the first MR sensor 22A. Then, the throttle valve 50A provided in the intake pipe 800 of the engine 810 is opened and closed. The control unit 300A also uses the power circuit 40 to generate a brushed DC motor 100B based on input information such as an external command from the ECU 700 or the like, or digital values of the A-phase and B-phase signals output from the second MR sensor 22B. To open and close the EGR valve 50B provided in the exhaust pipe 812. The EGR valve 50 </ b> B controls the recirculation amount of the exhaust gas from the exhaust pipe 812 to the intake pipe 800, and a cooler 815 is provided in the middle of the recirculation path 814.

  A throttle opening sensor is attached to a driven member that is driven by the DC motor 100A and opens and closes the throttle valve 50A. An EGR valve sensor is attached to a driven member that is driven by the DC motor 100B and opens and closes the EGR valve 50B. In addition, the output signals of the intake air amount detector, the air-fuel ratio sensor, the load sensor 816 for detecting the amount of depression of the accelerator pedal, and the crank angle sensor 817 for detecting the crank angle and the engine speed are respectively corresponding AD converters. Through the input port of the ECU 700. The output port of the ECU 700 is connected to an engine spark plug and a fuel injection valve via a corresponding drive circuit. The output port of the ECU 700 is connected to the DC motor 100A for driving the throttle valve and the DC motor 100B for driving the EGR valve via the power circuits 40A and 40B.

  That is, in the DC motor control unit 300A, the absolute position signal based on the relative origin position using the A phase, B phase signals, etc. obtained as the output of the first MR sensor unit 20 provided in the DC motor 100A. Is generated. The PWM signal generation unit 346 receives the output of the DC servo control unit 345, generates a PWM signal, and outputs the PWM signal to the DC motor drive control unit 41. According to the output of the DC motor drive control unit 41, the throttle valve 50A is opened and closed by the DC motor 100A via the power circuit (motor drive circuit) 40A. Similarly, the EGR valve 50B is also opened and closed by the DC motor 100B via the power circuit (motor drive circuit) 40B.

  When the power is turned off without the throttle valve 50A returning to its normal position for some reason, when the key switch is turned on, the control unit 300A acquires an absolute position signal from the EEPROM of the memory, and the throttle valve Recognize the relative origin position at the last stop of 50A. When the relative origin position corresponds to an abnormal stop away from the relative origin position Zα, a process for starting in a normal state is performed.

The opening degree of the throttle valve 50A is controlled with high accuracy using an absolute position signal.
Further, since the opening degree information indicating the relative origin position of the throttle valve 50A is obtained twice from the throttle opening degree sensor and the MR sensor unit 20, the reliability of the apparatus is improved.

  Furthermore, it is assumed that information of P2 = Z0B028560 as shown in FIG. 10, for example, is obtained from the EEPROM as an absolute position signal when restarting after an abnormal stop. The ECU generates and outputs an appropriate PWM control signal based on the PID control based on the information on the absolute position signal. Thus, after the key switch is turned on and before the engine is started by the user, the PWM signal is generated to drive the DC motor 100A, and the process of returning the opening of the throttle valve 50A to the fully closed position is quickly performed. Can be executed.

  According to the present embodiment, since the throttle valve and the EGR valve are driven by the DC motor based on the information of the absolute position signal generated based on the output signals of the pair of MR sensors, the position of each valve is extremely different. It can be controlled with high accuracy. The present invention can be easily realized by incorporating a simple program into a computer, and can provide an inexpensive and highly versatile DC motor control device. In addition, since the absolute position signal generated based on the output signals of the pair of MR sensors is recorded in the EEPROM, at the next start-up, it is determined whether or not there is an abnormal stop of the throttle valve or EGR valve of the vehicle. Even in the case of a stop, safe operation start can be realized.

Next, a third embodiment of the present invention will be described. FIG. 11 is a functional block diagram of a control device for a DC motor based on the third embodiment of the present invention.
In this embodiment, each function of the control unit 300 is incorporated in an in-vehicle ECU 1000 unlike the control unit 300 of FIG. The functions of the DC motor drive control unit 41 and the DC motor drive circuit 40 are also incorporated in the in-vehicle ECU 1000. The ECU 1000 includes a control unit 1012 including an upper processor 1010 and an upper memory 1014 for the control unit 300. The functions of the control unit 300, the DC motor drive circuit 40, and the DC motor drive control unit 41 are the same as the corresponding functions in FIG.
As the driven member, a plurality of in-vehicle devices driven by a DC motor can be targeted. For example, as a driven member, there are a power seat, a power window, an electronic turbocharger, a water pump, an oil pump, and the like in addition to the above-described example of the wiper. These driven members are accurately controlled by multi-rotation based on the multi-rotation / absolute position signal by the DC motor 100 with a brush, and can quickly return to a normal state upon restart after an abnormal stop. .

Also, the ECU 1000 of the third embodiment receives various types of information related to the control of the automobile and the engine (not shown) as in the ECU 700 of FIG.
Each of the DC motors that drive each driven member is provided with an MR sensor unit 20, and the A-phase and B-phase signals generated by each MR sensor unit 20 are serial signals corresponding to the ISO 26262 standard via a communication cable. Is transmitted to ECU 1000. Since information necessary for driving each driven member often includes information common to other driven members, it is desirable that the ECU 1000 collectively manage the information.

  According to the present embodiment, each driven member is driven by a DC motor based on the information of the absolute position signal generated based on the relative origin position using the output signal of the MR sensor unit having a pair of MR sensors. Driven. Therefore, the position of each driven member can be controlled with extremely high accuracy. The present invention can be easily realized by incorporating a simple program into a computer, and can provide an inexpensive and highly versatile DC motor control device. In addition, since the absolute position signal generated based on the output signals of the pair of MR sensors is recorded in the EEPROM, at the next start-up, the presence or absence of abnormal stop of each driven member of the vehicle is determined, and the abnormal stop Even in the case of, safe start of operation can be realized.

  Next, a fourth embodiment of the present invention will be described. In this embodiment, a backup power source is attached to the MR sensor unit, the control unit, and the EEPROM in each of the above embodiments. Since the data in the EEPROM is retained even after power from the battery is not supplied to the EEPROM after the vehicle has stopped abnormally, it can be used for safe restart of the vehicle. However, after an abnormal stop, the driven member may be in an unexpected inappropriate restart state in which only the driven member is forcibly driven instead of the normal normal restart via the car key switch. There is also. In this case, even if the driven member is rotated many times, the EEPROM data is not updated. Even in this unexpected state, it is desirable to avoid a situation where the automobile is restarted. Therefore, in order to further improve safety, a backup power source is secured so that the processing from the output of the MR sensor unit to the control unit of the DC motor being recorded in the EEPROM is maintained even after the automobile is stopped.

  As a backup power source of the EEPROM, for example, there are a button battery, a lithium battery, and the like. These backup power supplies are normally charged using the battery 42 as a power source with the key switch turned on. When the battery power is lost, it functions as a power source for the MR sensor unit, the control unit, and the EEPROM. Thereby, even if the battery power supply is lost due to an unexpected situation, the absolute position signal accompanying the driving of the driven member at the time of abnormal stop is recorded in the EEPROM.

  In addition, for some reason, while the absolute position signal is being recorded in the EEPROM, the power from the battery is not supplied to the EEPROM, or the power supply voltage temporarily drops to a rated voltage, for example, 1.2 V abnormally. It can also happen. Even in such a case, it is possible to prevent incomplete data from being recorded in the EEPROM by providing a backup power supply to the EEPROM.

  Next, a fifth embodiment of the present invention will be described. The DC motor control apparatus according to the present invention drives not only a DC motor mounted on an automobile but also a driven member that requires a multi-rotation / absolute position signal based on information on the position of the absolute origin in other fields. It can also be applied to a DC motor. For example, by employing the DC motor of the present invention for an actuator of a robot hand or the like, the position of the actuator can be controlled with an absolute position signal with extremely high accuracy.

DESCRIPTION OF SYMBOLS 10 Motor housing 11 Permanent magnet 12 Amateur 13 Rotating shaft 14 Reduction gear 15 Power supply terminal 16 Brush 17 Commutator 18 End bracket (or shield cap)
20 MR sensor unit 21 Magnet 22 MR sensor 23 Processing circuit unit 24 Bearing 25 Bearing 40 DC motor drive circuit 40A Power circuit 40B Power circuit 41 DC motor drive control unit 42 Battery 43 Ignition switch 50 Driven member 50A Throttle valve 50B EGR valve 100 DC motor 100A DC motor 100B DC motor 300 DC motor control unit 310 Communication control unit 320 Memory control unit 330 Memory 331 ROM
332 RAM
333 EEPROM
341 Self-initialization processing unit 342 Z-phase signal generation unit 343 Z-phase width signal generation unit 344 Relative origin position signal generation unit 345 DC servo control unit 346 PWM signal generation unit 500 In-vehicle ECU
600 Printed circuit board 700 Engine control ECU
1000 ECU

Claims (15)

A control unit that generates and outputs a drive signal for the DC motor;
An MR sensor unit that detects rotation of the rotary shaft of the DC motor by a pair of MR sensors;
In a motor control device that controls electric power supplied via a brush to an amateur fixed to the rotating shaft,
The MR sensor unit is
Positioning information indicating a state in which the incremental A-phase and B-phase signals accompanying the rotation of the rotary shaft and the output signals of the A-phase and B-phase are in a specific relationship based on the outputs of the pair of MR sensors And output
The control unit is
The A-phase and B-phase output signals and the positioning information from the MR sensor unit obtained by starting the DC motor at a predetermined rotational speed in both forward and reverse directions by an initialization drive signal and driving the DC motor And the information on the relative origin position (Zα) of the MR sensor with respect to the rotation axis from the synchronous relationship with the initialization drive signal,
A motor control device configured to convert all data of the information on the A phase, the B phase, and the relative origin position into absolute signal data and record the data in an EEPROM. In claim 1,
The control unit is
A Z-phase width signal is generated using the relative origin position (Zα) signal obtained along with the start-up operation of the DC motor and the output signal of the A phase or the B phase,
A motor control device configured to give the address of the EEPROM to the Z-phase width signal data to obtain the absolute signal data. In claim 1 or 2,
The control unit is
Based on the relative origin position Zα, Z phase signals (Z0, Z1, Z2,-, Zn) are set in synchronization with the output signals of the A phase or the B phase at intervals of 360 degrees.
The address of the EEPROM is assigned to the information on the A phase, the B phase, the relative origin position, and all the data information of the Z phase signal, and the absolute signal data is recorded in the EEPROM.
A motor control device configured to use the data of the EEPROM for controlling multi-rotation of the DC motor. In claim 3,
The control unit is
The address of the EEPROM is given to the combination of the accumulated addition value data for each rotation of the output signals of the A phase and the B phase accompanying the rotation of the rotating shaft and the information of the relative origin position (Zα). A motor control device characterized in that the absolute signal data is used. In claim 1 or 2,
The MR sensor unit is
A function of generating an incremental A-phase / B-phase signal by performing an arctangent operation on a digital value of the SIN and COS waveform outputs of the pair of MR sensors corresponding to the start-up operation;
A motor control having a function of outputting at least one positioning information at an interval of 360 degrees corresponding to a specific angle of the A-phase or B-phase signal based on a result of the arctangent calculation. apparatus. In claim 5,
The MR sensor unit is
A motor control device having a function of outputting a plurality of different types of positioning information having different resolutions as the positioning information. In claim 1 or 2,
The control unit is
Comparing the incremental A-phase and B-phase output signals of the MR sensor unit with the drive with the initialization drive signal to determine whether the response relationship of the DC motor or the MR sensor is normal;
A control apparatus for a direct current motor, wherein the absolute signal data is generated based on the incremental A-phase and B-phase output signals when the correspondence is normal. In claim 1 or 2,
The control unit is
An address is given to the incremental A-phase and B-phase output signals accompanying normal operation of the DC motor, and recorded in the EEPROM as the A-phase and B-phase absolute signals. Motor control device. In claim 1 or 2,
A battery as a power source of the MR sensor unit, the control unit, and the EEPROM;
A backup power source that normally functions as a power source for the MR sensor unit, the control unit, and the EEPROM is provided when power is supplied from the battery and power is no longer supplied from the battery. A motor control device. In claim 1 or 2,
The control unit of a DC motor, wherein the control unit is configured as an ASIC and is fixed in an end bracket of the DC motor. In claim 1 or 2,
The DC motor is a DC motor that drives a driven member of an automobile,
The control unit is
It is fixed to the vehicle-mounted ECU or the driven member,
Configured to perform serial communication with the MR sensor unit;
When the automobile is started, the absolute position signal is acquired from the EEPROM, the relative origin position of the driven member at the previous stop is recognized, and the origin position is separated from the relative origin position of the MR sensor. In a case corresponding to an abnormal stop, the driven member is driven by the DC motor to return to a normal state until the automobile engine is started. DC motor control device. A brushed DC motor comprising an MR sensor unit, wherein power is supplied via a brush to an armature fixed to a rotating shaft, and is configured to rotate in both forward and reverse directions.
In the DC motor, the electric power is supplied from a DC motor driving circuit in response to an instruction from an external control unit.
The MR sensor unit is
A plate-like magnet fixed to one end surface of the rotating shaft;
A pair of MR sensors that are fixed in an end bracket of the DC motor so as to face the magnet in the axial direction of the rotating shaft and detect a transverse magnetic field of the magnet;
A processing circuit unit fixed to the DC motor,
The magnet is N, S single magnetization,
The processing circuit unit is
A function of taking analog outputs of SIN and COS waveforms of the pair of MR sensors as input along with rotation of the rotary shaft corresponding to an operation command from the control unit, and converting them into digital values;
A function of generating an incremental A-phase / B-phase signal by calculating an arctangent of a digital value of the SIN and COS waveform outputs of the pair of MR sensors;
A function of outputting at least one positioning information at an interval of 360 degrees corresponding to a specific angle of the signal of the A phase or the B phase based on the result of the arctangent calculation;
Serial data which converts the digital data of the incremental A-phase / B-phase signals and the positioning information into transmission data for serial transmission conforming to the serial transmission communication standard, and transmits it to the control unit via a single transmission path. A DC motor with a brush having a communication function. In claim 12,
The control unit is configured as an ASIC and is fixed in an end bracket of the DC motor,
The control unit is
It has a self-initialization processing unit,
The self-initialization processing unit
Generate and output an initialization drive signal for driving the DC motor in a forward and reverse direction at a predetermined rotational speed, and output the incremental A phase and B phase signals of the MR sensor synchronized with the start-up operation of the DC motor, and the A function to acquire positioning information;
In response to the initialization drive signal, the DC motor is started and operated at a predetermined rotational speed in both forward and reverse directions, and the output signals of the A phase and B phase from the MR sensor unit obtained by driving the DC motor and the positioning A function of determining the relative origin position of the MR sensor with respect to the rotation axis from the relationship of synchronization between the information and the initialization drive signal;
Absolute signal data by assigning an EEPROM address to the combination of the cumulative addition value data for each rotation of the A-phase and B-phase output signals accompanying the rotation of the rotary shaft and the information on the relative origin position. And a function of recording the data in the EEPROM. A DC motor control unit that generates and outputs a drive signal for a brushed DC motor,
The DC motor is configured such that electric power is supplied to an armature fixed to a rotating shaft through a brush, and a signal associated with the rotation of the rotating shaft of the DC motor is provided with a pair of MR sensors. In what is received from the sensor unit,
The control unit is
Incremental A-phase / B-phase output signals from the MR sensor unit obtained by driving the direct-current motor at a predetermined rotational speed in both forward and reverse directions by the initialization drive signal, and the Positioning information indicating a state in which the output signals of the A phase and the B phase are in a specific relationship;
Based on the relationship between the initialization drive signal, the A-phase and B-phase output signals from the MR sensor unit obtained by driving the DC motor, and the synchronization of the positioning information, the MR sensor relative to the rotating shaft Get the information of the origin position (Zα)
A direct current motor control unit configured to convert all data of the A phase, B phase, and relative origin position information into absolute signal data and record the data in an EEPROM. In claim 14,
The control unit is
A Z-phase width signal is generated using the relative origin position (Zα) signal and the A-phase or B-phase output signal,
A control unit for a DC motor, wherein the absolute signal data is provided by giving an address of the EEPROM to the Z-phase width signal data.

Images