JP4351924B2 - In-vehicle motor control device and power steering device. - Google Patents

Description

  The present invention relates to an in-vehicle motor control device that controls a motor to which driving power is supplied by a battery mounted on a vehicle, and a power steering device including the motor control device.

  Many control devices that operate using a battery as a power source and control energization of a motor are used in vehicles. For example, an electric power steering device is a kind of the steering mechanism, and a steering torque applied to a steering wheel by a driver is detected by a torque sensor, and a motor is driven by PWM control according to the steering torque, so that an auxiliary steering is provided to the steering mechanism. It is designed to apply power.

  In recent years, not only small vehicles but also medium-sized and large vehicles tend to be desired to be equipped with a power steering device, which is addressed by increasing the capacity of the motor and its control device. As for the motor, it is proposed that a brushless motor is adopted instead of the brushed DC motor having a current restriction, and that the controller is given a function of boosting the battery voltage to obtain a high output. Yes.

For example, Patent Document 1 discloses a configuration in which a boosting operation is performed according to a required motor current using a control device having a boosting function. Patent Document 2 discloses a configuration in which a motor control device and a step-up function unit are arranged inside an ECU (Electronic Control Unit) to obtain a larger steering assist force.
JP 2001-260907 A Japanese Patent Laid-Open No. 2003-200838

As described above, considering the limit of the battery output when increasing the capacity of the power steering device, it is necessary to increase the efficiency of the motor, reduce the loss generated in the control device, reduce the wiring loss, etc. . However, the following problems occur in configurations such as those disclosed in Patent Documents 1 and 2.
Here, a description will be given with reference to FIGS. FIG. 8 shows that the wiring resistance between the battery 101 and the motor 102 is 20 mΩ per one, and the motor control device 103 having a boosting function is arranged at a ratio of 9: 1 near the motor 102. (That is, (distance between battery 101 and control device 103) :( distance between control device 103 and motor 102) = 9: 1). Further, it is assumed that the rated current Im of the motor 102 when the battery current Ib = 100 Adc and the step-up rate “1” is 120 Arms. FIG. 9 shows a change in wiring loss corresponding to a change in the boost rate α when the motor 102 is designed with the voltage specification optimized in accordance with the boost rate.

The wiring loss due to the battery current Ib is obtained by (resistance value: 18 mΩ) × (Ib) ² × (number of wirings: 2), and the wiring loss due to the motor current Im is (resistance value: 2 mΩ) × (Im / α) ² X (Number of wirings: 3) As is clear from FIG. 9, in the arrangement form of FIG. 8, the wiring loss due to the battery current Ib is dominant. Therefore, even if the battery voltage is boosted to reduce the wiring loss due to the motor current Im, the overall wiring loss is reduced. There is little reduction effect.

  FIG. 10 shows a case where the control device 103 is arranged at a ratio of 1: 9 on the vicinity side of the battery 101 (that is, (distance between the battery 101 and the control device 103): (between the control device 103 and the motor 102). Distance) = 1: 9). Other conditions are the same as those in FIG. FIG. 11 shows a change in wiring loss corresponding to a change in the step-up rate α corresponding to the arrangement form of FIG. In this case, if the boosting rate α is sufficiently high, the effect of reducing the wiring loss due to the boosting can be obtained.

  However, when the control device 103 is arranged in the vicinity of the battery 101 as shown in FIG. 10, it is necessary to extend the wiring of the rotational position sensor and the torque sensor that need to be connected between the motor 102 and the control device 103 this time. There is. Then, since these sensor signals are analog signals, they are easily affected by noise, causing false detection, and increasing the number of wirings that increase the distance causes an increase in cost.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce a wiring loss and to suppress an increase in the number of wires in which a wiring distance becomes long, and a motor control thereof. An object of the present invention is to provide a power steering device including the device.

In order to achieve the above object, an in-vehicle motor control device according to claim 1 is disposed in the vicinity of a battery mounted on a vehicle and boosts an output voltage of the battery;
A drive control unit that is disposed in the vicinity of a motor to which drive power is supplied by the battery and that performs PWM control of driving of the motor based on a boosted voltage boosted by the booster circuit unit, the booster circuit unit, and the drive It is comprised with the communication means for performing two-way communication between control parts .

  In other words, since the booster circuit unit is arranged in the vicinity of the battery and performs the boosting operation of the battery voltage, the wiring between the booster circuit unit and the motor where the wiring becomes longer can be increased in voltage and current, and the wiring loss is reduced. Is done. On the other hand, since the drive control unit is arranged in the vicinity of the motor, in order to obtain various information related to the motor necessary for drive control, the wiring distance for obtaining the output signal of the sensor arranged on the motor side is shortened.

  A power steering apparatus according to a twelfth aspect includes the on-vehicle motor control apparatus according to any one of the first to eleventh aspects, and assists the driving of the steering by the output torque of the motor. That is, the motor of the power steering apparatus is usually disposed in the vicinity of the steering shaft. In order to assist the driver's steering force by driving the motor, it is necessary to obtain information such as the rotational position of the steering shaft and the torque acting on the shaft using a rotational position detection sensor or a torque sensor. is there. Therefore, the position of the motor is arranged away from the battery, and it is necessary to route various sensor signal wirings between the control device and the motor. Therefore, if the in-vehicle motor control device of the present invention is applied to a power steering device, various problems that occur with the above system configuration are solved.

  According to the in-vehicle motor control device of the present invention, it is possible to obtain a high motor output by minimizing wiring loss within a limited battery output. And by applying the vehicle-mounted motor control apparatus of this invention, a high output power steering apparatus can be comprised.

  Hereinafter, an embodiment in which the present invention is applied to an electric power steering apparatus will be described with reference to FIGS. In FIG. 1 showing the overall configuration of the power steering apparatus 100, the rotational force of the steering shaft 9 whose one end is fixed to the steering handle 8 disposed in the passenger compartment is connected to both ends of the rack shaft by a rack and pinion mechanism 10. 11 is transmitted as a force for changing the direction of the wheel 12 attached via the motor 11. A three-phase brushless DC motor 4 for assisting rotational force is disposed on the steering shaft 9, and the motor 4 and the shaft 9 are connected via a speed reduction mechanism 6.

  The booster circuit unit 2 that operates using the battery 1 as a power source and boosts the battery voltage is disposed adjacent to or in close contact with the vicinity of the battery 1. The voltage boosted by the booster circuit unit 2 is supplied to the motor drive control unit 3 via the wirings 16a and 16b. The motor drive control unit 3 is arranged adjacent to or in close contact with the brushless motor 4 so as to PWM-control the energization of the motor 4. A battery voltage is supplied to the motor drive control unit 3 via a wiring 17 as a control power source, and the signal line 14 of the torque sensor 7 for detecting the torque applied to the steering shaft 9 and the rotational position of the motor 4 are set. A signal line 15 of the resolver 5 to be detected is connected.

  Next, the configuration of the booster circuit unit 2 will be described with reference to FIG. The input terminals 30 and 31 of the booster circuit unit 2 are connected to the battery 1, but the positive input terminal 30 is connected to one end of the reactor 38 via the shunt resistor 32. A series circuit of a capacitor 34, a power supply circuit 35, and voltage dividing resistors 36 and 37 is connected in parallel between a common connection point of the shunt resistor 32 and the reactor 38 and the negative input terminal 31.

  Both ends of the shunt resistor 32 are connected to a current detection circuit 33 that level-shifts and amplifies the terminal voltage, and an output terminal of the current detection circuit 33 is connected to an analog / digital conversion input terminal of the microcomputer 47. The power supply circuit 35 generates and supplies power for operation of the microcomputer 47, the switching IC 41, and the communication IC 48, and the voltage dividing resistors 36 and 37 divide the battery voltage and supply it to the analog / digital conversion input terminal of the microcomputer 47. It is like that.

The other end of the reactor 38 is connected to the drain of the FET 39 whose source is connected to the negative side input terminal 31 and the source of the FET 40. The drain of the FET 40 is connected to the positive output terminal 45. A series circuit of voltage dividing resistors 42 and 43 and a capacitor 44 are connected between the positive output terminal 45 and the negative output terminal 46.
The input terminal of the switching IC 41 is supplied with a signal Sa that is a potential divided by the voltage dividing resistors 42 and 43 and a signal Sb output from the microcomputer 47. The output terminal from which the switching IC 41 outputs a PWM signal is connected to the gate terminals of the FETs 39 and 40 via a gate drive circuit (not shown). The communication input / output terminal of the microcomputer 47 is connected to the communication line 13 via the communication IC 48.

  Next, the configuration of the drive control unit 3 will be described with reference to FIG. A capacitor 63 and a power supply circuit 64 for supplying power such as a microcomputer 77 are connected between an input terminal 61 and a negative input terminal 62 that are directly connected to the positive side of the battery 1 via the wiring 17. . A positive input terminal 60 connected to the positive output terminal 45 of the booster circuit unit 2 via the wiring 16 a is connected to the inverter main circuit 70 via a shunt resistor 65.

  The negative side input terminal 62 is connected to the negative side output terminal 46 of the booster circuit unit 2 through the wiring 16b. A series circuit of voltage dividing resistors 80 and 81 and a capacitor 67 are connected in parallel between the inverter main circuit 70 side of the shunt resistor 65 and the negative input terminal 62. The inverter main circuit 70 is configured by connecting six FETs 70u to 70z in a three-phase bridge. The U phase and W phase of each arm output point constituting the inverter main circuit 70 are connected to output terminals 71 and 73 via shunt resistors 68 and 69, respectively, and the V phase is directly connected to the output terminal 72. .

  Output terminals 71, 72, 73 of the inverter main circuit 70 are connected to the windings of the respective phases of the brushless motor 4. The voltage dividing resistors 80 and 81 divide the DC voltage applied between the input terminals 60 and 62 and supply it to the analog / digital conversion input terminal of the microcomputer 77. The shunt resistors 65, 68, and 69 are connected to current detection circuits 66, 74, and 75 that amplify the voltage at both ends by level shifting, and the output terminals of the current detection circuits 66, 74, and 75 are analog / digital conversion of the microcomputer 77. Connected to the input terminal. The microcomputer 77 outputs an on / off signal (PWM signal) to each FET 70u to 70z of the inverter main circuit 70 via a gate drive circuit (not shown). The communication input / output terminal of the microcomputer 77 is connected to the communication line 13 via the communication IC 76.

An input terminal of the resolver detection circuit 78 is connected to the resolver 5 disposed in the brushless motor 4 via the wiring 15, and an output terminal of the resolver detection circuit 78 is connected to an input terminal of the microcomputer 77. The input terminal of the torque detection circuit 79 is connected to the torque sensor 7 disposed on the steering shaft 9 via the wiring 14, and the output terminal of the torque detection circuit 79 is connected to the analog / digital conversion input terminal of the microcomputer 77. It is connected.
The microcomputer 47 and communication IC48 of the booster circuit portion 2, a communication line 13, the microcomputer 77 and a communication IC76 of the motor drive control unit 3 constitutes the communication means 8 9. Communication performed between the communication ICs 48 and 76 is, for example, serial communication such as RS-485. The booster circuit unit 2 and the motor drive control unit 3 constitute a vehicle-mounted motor control device 90.

  Next, the operation of the present embodiment will be described with reference to FIGS. When the battery power is turned on, power is supplied to the input terminal 61 of the motor drive control unit 3 via the wiring 17. Then, the power supply circuit 64 generates and supplies power for operation of the microcomputer 77, the current detection circuits 66, 74, and 75, the communication IC 76, the resolver detection circuit 78, and the torque detection circuit 79, and starts operating.

  The current detection circuits 66, 74, and 75 amplify the terminal voltages of the shunt resistors 65, 68, and 69 to which the current detection circuits 66, 74, and 75 are connected to the microcomputer 77, for example, 20 times on the basis of 2.5V. Formed signal. Further, the voltage dividing resistors 80 and 81 form a signal obtained by dividing the DC voltage applied to the positive input terminal 60 to, for example, 1/10. The microcomputer 77 periodically detects the input DC voltage of the motor drive control unit 3, the winding current of the brushless motor 4 and the input current of the motor drive control unit 3 by performing analog / digital conversion. Yes.

  The resolver detection circuit 78 supplies an excitation signal to the resolver 5, receives a cosine / sine signal output from the resolver 5, performs resolver / digital conversion, and supplies a 12-bit digital signal to the microcomputer 77. The microcomputer 77 detects the rotational position of the brushless motor 4 by referring to the digital signal output from the resolver detection circuit 78. The torque detection circuit 79 differentially amplifies the signal output from the torque sensor 7 and supplies it to the microcomputer 77 as a torque signal. The microcomputer 77 detects torque applied to the steering shaft 9 by periodically analog / digital converting the torque signal.

  The microcomputer 77 feedback-controls the motor current, forms a current command based on the detected rotational position of the motor 4 and torque information, and determines the output voltage by comparing it with the detected motor current. The determined output voltage is converted into a PWM signal in the microcomputer 77, and is output to each of the FETs 70u to 70z as a gate signal. Each FET 70u-70z supplies PWM voltage to each phase of the brushless motor 4 by performing an on / off operation according to a given gate signal. Accordingly, current control of the brushless motor 4 corresponding to the torque obtained by the torque sensor 7 is executed.

  Here, FIGS. 4A and 4B are flowcharts showing mainly the contents of processing related to communication performed by the microcomputer 47 on the booster circuit unit 2 side and the microcomputer 77 on the drive control unit 3 side, respectively. . The microcomputer 77 includes means for detecting the rotational speed of the brushless motor 4 from the detected change in rotational position (step B1), and determines a boost voltage command corresponding to the rotational speed to the booster circuit unit 2 (step B1). Step B2).

  Specifically, the microcomputer 77 sets the boost to zero when the rotation speed of the brushless motor 4 is equal to or less than a predetermined value, and determines the boost voltage corresponding to the excess when the rotation speed exceeds the predetermined rotation speed. For example, when the steering wheel 8 is operated by rapid rotation by the driver, the rotor of the brushless motor 4 rotates via the steering shaft 9 and the speed reduction mechanism 6. Further, the rotor of the brushless motor 4 is rotated at a high speed by the drive control unit 3 in accordance with the torque applied to the handle 8.

  At this time, the microcomputer 77 detects the number of rotations of the rotor of the brushless motor 4 and immediately determines a boost voltage command. An example of the relationship between the rotation speed of the brushless motor 4 and the boost voltage command is shown in FIG. The microcomputer 77 periodically converts this boosted voltage command into serial data and outputs it to the communication output terminal, thereby transmitting a boosted voltage command corresponding to the rotational speed to the booster circuit unit 2 (step B3). Then, the communication IC 76 amplifies it, converts it into a two-line differential signal, and outputs it to the communication line 13.

  On the other hand, also in the booster circuit unit 2, when battery power is turned on, power is supplied to the microcomputer 47, the switching IC 41, and the communication IC 48 by the action of the power supply circuit 35. The current detection circuit 33 forms a signal that is amplified 20 times on the basis of, for example, 2.5 V that can input the voltage across the shunt resistor 32 to the microcomputer 47. The voltage dividing resistors 36 and 37 divide the battery voltage to 1/10, for example.

  The microcomputer 47 detects the battery current and the battery voltage by periodically analog / digital converting the output signal of the current detection circuit 33 and the output signals of the voltage dividing resistors 36 and 37 (steps A1 and A2). The microcomputer 47 periodically converts the battery current and the battery voltage into serial data and outputs the serial data to the communication output terminal (steps A7 and A8). The communication IC 48 amplifies it, converts it into a two-line differential signal, and outputs it to the communication line 13.

At the same time, the microcomputer 47 periodically receives the serial signal of the communication line 13 via the communication IC 48, thereby recognizing the boost voltage command from the motor drive control unit 3 (step A3). The microcomputer 47 outputs an analog signal Sb from the digital / analog output terminal based on the boost voltage command.
Signal Sb = (boost voltage command) / 10
It is set like this.

  The switching IC 41 outputs a high-frequency signal that alternately turns on and off the FETs 39 and 40, and the ratio is determined by the signals Sa and Sb that are input signals. The signal Sa is obtained by dividing the voltage of the capacitor 44 by, for example, 1/10 by the voltage dividing resistors 42 and 43. Then, the switching IC 41 increases the on-ratio of the FET 39 (the off-ratio of the FET 40) if Sa <Sb by the input signals Sa and Sb, and the on-ratio of the FET 39 (the off-ratio of the FET 40) if Sa> Sb. Operates to decrease.

  When the FET 39 is turned on, current flows through the path of the reactor 38 → the FET 39 and energy is stored in the reactor 38. When the FET 39 is turned off and the FET 40 is turned on from this state, the energy stored in the reactor 38 is discharged through the path of the reactor 38 → the FET 40 → the capacitor 44, and the terminal voltage of the capacitor 44 rises. That is, since the on / off ratio of the FETs 39 and 40 is adjusted by the signal Sa obtained by dividing the terminal voltage of the capacitor 44 and the signal Sb from the microcomputer 47, the terminal voltage of the capacitor 44 is controlled by the signal Sb.

Since the signal Sb is determined by the microcomputer 47 based on the boosted voltage command transmitted by the drive control unit 3, the output voltage of the booster circuit unit 2 is controlled by the motor drive control unit 3. . For example, it is assumed that the motor drive control unit 3 determines the boost voltage command as 0 V based on the rotation speed of the brushless motor 4. Then, the microcomputer 47 compares the boost voltage command obtained through communication with the battery voltage (for example, 12V) (step A4). in this case,
(Battery voltage) ≥ (boost voltage command)
Therefore, the microcomputer 47 determines the signal Sb to be zero and outputs it (step A6). Then, since the switching IC 41 turns off the FET 39 and turns on the FET 40, the booster circuit unit 2 does not execute the boosting operation. Therefore, the battery voltage is output to the output terminals 45 and 46 as they are.

Further, it is assumed that the motor drive control unit 3 determines the boost voltage command as 20 V, for example, based on the rotation speed of the brushless motor 4. in this case,
(Battery voltage) <(boost voltage command)
Therefore, the microcomputer 47 determines the signal Sb to be 2V and outputs it (step A5). Then, the switching IC 41 adjusts the on / off ratio of the FETs 39 and 40, and the boosting circuit unit 2 executes the boosting operation, whereby the boosted voltage of 20V is output to the output terminals 45 and 46.
Also, when the motor drive control unit 3 determines the boost voltage command to be 10V,
(Battery voltage) ≥ (boost voltage command)
Therefore, since the microcomputer 47 sets the signal Sb to zero (step A6), the booster circuit unit 2 does not execute the boosting operation.

  The microcomputer 77 of the motor drive control unit 3 also has an abnormal operation determination function of the booster circuit unit 2. The microcomputer 77 performs analog / digital conversion on the potential divided by the voltage dividing resistors 80 and 81 to detect a DC voltage (step B4), and detects a DC current by using the shunt resistor 65 (step B5). Then, the boosted voltage command transmitted to the booster circuit unit 2 in step B3 is compared with the value obtained by adding the product of the DC current value and the resistance value of the wiring 16 to the detected DC voltage (step B8). Is larger than the predetermined value (“NG”), it is determined that the booster circuit unit 2 is abnormal (step B9). That is, Steps B8 and B9 correspond to determination means.

  Further, the microcomputer 77 receives the battery current value and the battery voltage value transmitted from the booster circuit unit 2 (steps B6 and B7), and calculates the input power of the booster circuit unit 2 based on these values, then the motor drive control unit The output power of the booster circuit unit 2 is obtained from the DC voltage 3 and the DC current, and the loss of the booster circuit unit 2 is obtained from the difference between the two. Then, the abnormality of the booster circuit unit 2 is determined by comparing the loss with a normal value (step B10). If the former exceeds the latter (“NG”), it is determined that the booster circuit unit 2 is abnormal. (Step B11).

  Further, the microcomputer 77 monitors the battery voltage value transmitted from the booster circuit unit 2 and determines that the battery 1 is abnormal when, for example, it exceeds the normal range of 8 to 16 V (step B12, “NG”). (Step B13). Further, the microcomputer 77 monitors the battery current value transmitted from the booster circuit unit 2 and, for example, when it becomes 100 A or more (step B14, “≧”), the current to be supplied to the winding of the motor 4 is supplied. Limit the battery to prevent overcurrent (step B15).

According to this embodiment, as described above, the drive control unit 3 disposed in the motor 4 near sends a boost voltage command to the booster circuit portion 2 via the communication means 8 9, arranged near the battery 1 The booster circuit unit 2 supplies a boosted voltage to the motor drive control unit 3 by performing a boosting operation according to the command.
That is, since the motor drive control unit 3, the brushless motor 4, and the torque sensor 7 are adjacent to each other and the wirings 14 and 15 are extremely short, it is possible to make it less susceptible to noise. Also, noise countermeasures are easy. On the other hand, since the distance between the arrangements of the motor drive control unit 3 and the booster circuit unit 2 becomes longer, the communication line 13 between them becomes longer.

  Here, the effect on the wiring loss when the booster circuit unit 2 and the drive control unit 3 are arranged separately as in the present embodiment will be described with reference to FIGS. FIG. 6 corresponds to FIG. 10 and FIG. 12 of the conventional example. The drive control unit 3 is disposed at a 9: 1 location near the motor, and the booster circuit unit 2 is disposed at a 1: 9 location near the battery 1. Shows the case. Other conditions are the same as in the conventional case.

  According to FIG. 7, by designing the brushless motor 4 with high voltage specifications on the premise of boosting, the DC current and the motor current can be reduced as the boosting rate α increases, and the configuration of the present invention is adopted. It is shown that the wiring loss can be reduced more than before by boosting the voltage. The ability to reduce wiring loss means that the output of the brushless motor 4 can be increased within a limited battery output. The effect of reducing the wiring loss is clearly greater than that in FIG. 8 in the case where the conventional control device 103 is arranged near the motor. Further, even if the control device 103 is arranged in the vicinity of the battery as compared with FIG. 10, the effect of reducing the wiring loss can be confirmed with a small boosting rate.

Further, according to the present embodiment, the drive control unit 3 determines the abnormality of the booster circuit unit 2 based on the result of comparing the boosted voltage command transmitted to the booster circuit unit 2 with the detected boosted voltage. It can be determined whether or not the circuit unit 2 is operating appropriately in response to the command. Further, the boosting circuit unit 2 transmits the detection result of the battery voltage to the drive control unit 3 through the communication means 8 9 and the battery current, the drive control unit 3 monitors the transmitted battery voltage battery The abnormality determination of 1 was performed, the transmitted battery current value was monitored, and the winding current of the motor 4 was limited as necessary. Therefore, overcurrent of the battery 1 can be prevented.

  Further, the drive control unit 3 controls the drive of the brushless motor 4. That is, when a brushed DC motor is used, there are two wires between the drive circuit and the motor, but when the brushless motor 4 is used, there are three wires. Therefore, if the drive control unit 3 is adjacent to the motor 4 as in the present embodiment, the wiring distance is shortened even if the number of wirings is increased, so that the wiring process can be easily performed and the increase in cost is suppressed. be able to.

In addition, in this embodiment, by detecting the rotational position of the rotor in the motor 4 using the resolver 5, the number of wires required between the resolver 5 and its detection circuit 78 is six. Similarly, by making the drive control unit 3 adjacent to the motor 4, their wiring distance can be shortened.
The drive control unit 3 includes a power supply circuit 64 for generating a control power supply from the battery voltage, and the power supply circuit 64 is directly connected to the positive power supply of the battery 1 instead of the output line of the booster circuit unit 2. When the booster circuit unit 2 becomes inoperable, the microcomputer 77 of the drive control unit 3 can operate even when the booster circuit unit 2 becomes inoperable, and other devices are connected to the power steering apparatus 100 by communication means (not shown). It can be notified that an abnormality has occurred.

  The in-vehicle motor control device 90 is applied to the power steering device 100 that assists the driving of the steering shaft 9 by the output torque of the motor 4. That is, the motor 4 of the power steering apparatus 100 is disposed in the vicinity of the steering shaft 9, and the resolver 5, the torque sensor 7, and the like are used to assist the driver's steering force by driving the motor 4. It is necessary to obtain information such as the rotational position and the torque acting on the shaft 9. Therefore, the motor 4 is inevitably arranged away from the battery 1, and it is necessary to route various sensor signal wires between the drive control unit 3 and the motor 4. Therefore, by applying the in-vehicle motor control device 90, it is possible to solve various problems that occur with the system configuration of the power steering device 100. And the high output power steering apparatus 100 can be comprised.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible.
The drive control unit 3 is preferably arranged as close as possible to the motor 4, that is, close to the motor 4. Similarly, the booster circuit unit 2 is preferably arranged as close as possible to the battery 1. Further, if possible, the drive control unit 3 and the motor 4, and the booster circuit unit 2 and the battery 1 may be configured integrally.

As a means for detecting the rotational position of the rotor, a rotary encoder or the like may be used instead of the resolver 5. Further, a position detection element such as a Hall IC may be used, or a period during which the element outputs a detection signal may be measured, and the interval between them may be calculated and complemented.
The drive control unit 3 may determine whether the booster circuit unit 2 or the battery 1 is abnormal or limit the winding current of the motor 4 as necessary. Moreover, what is necessary is just to select suitably the information transferred between the booster circuit part 2 and the drive control part 3 according to an individual design.

A power supply for control generated on the booster circuit unit 2 side may be supplied without providing the power supply circuit 64 in the drive control unit 3.
Instead of the brushless motor 4, other three-phase motors such as an induction motor may be used.
A configuration in which the booster circuit unit and the drive control unit operate independently without providing a communication unit may be employed. That is, the booster circuit unit may always perform a boosting operation at a constant boosting rate.
The present invention is not limited to the power steering device 100 and can be applied as long as it can drive and control a vehicle-mounted motor.

FIG. 1 is a functional block diagram showing an overall configuration of an apparatus according to an embodiment when the present invention is applied to an electric power steering apparatus. The figure which shows the electric constitution of the step-up circuit part The figure which shows the electric constitution of a drive control part (A), (b) is a flowchart which mainly shows the processing content regarding the communication performed between both by the microcomputer of the step-up circuit unit side and the microcomputer of the drive control unit side, respectively. The figure which shows an example of the relationship between the rotation speed of a brushless motor, and a boost voltage command Between the battery and the motor, a diagram showing a state in which the drive control unit is arranged at 9: 1 near the motor and the booster circuit unit is arranged at 1: 9 near the battery. The figure which shows the state from which wiring loss changes, when the boosting rate of a booster circuit part is changed based on the arrangement | positioning form of FIG. The figure which shows the case where the conventional motor control apparatus is arrange | positioned in the position of the ratio 9: 1 near a motor. FIG. 7 equivalent diagram based on the arrangement of FIG. The figure which shows the case where a motor control apparatus is arrange | positioned in the position of ratio 1: 9 near a battery. FIG. 7 equivalent diagram based on the arrangement of FIG.

Explanation of symbols

In the drawings, 1 denotes a battery, 2 booster circuit unit, the drive control unit (determining means) 3, the brushless motor 4, the resolver 5 (rotational position detecting means), 8 9 communication means, 90 car motor control An apparatus 100 is a power steering apparatus.

Claims (12)

A booster circuit unit disposed in the vicinity of a battery mounted on a vehicle and boosting an output voltage of the battery;
A drive control unit that is disposed in the vicinity of a motor to which driving power is supplied by the battery, and that performs PWM control of driving of the motor based on a boosted voltage boosted by the boosting circuit unit ;
An in-vehicle motor control apparatus comprising: a communication unit for performing bidirectional communication between the booster circuit unit and the drive control unit . A booster circuit unit disposed in the vicinity of a battery mounted on a vehicle and boosting an output voltage of the battery;
A drive control unit that is disposed in the vicinity of a motor to which driving power is supplied by the battery, and that performs PWM control of driving of the motor based on a boosted voltage boosted by the boosting circuit unit;
An in- vehicle motor control device comprising: a communication unit for performing digital communication between the booster circuit unit and the drive control unit . The drive control unit, via said communication means, vehicle motor control apparatus according to claim 1, wherein transmitting the boost voltage command on the booster circuit portion. The drive control unit includes a determination unit that detects the boost voltage and determines an abnormality of the boost circuit unit based on a result of comparing the boost voltage command with the detected boost voltage. The on-vehicle motor control device according to claim 3. The booster circuit unit, via said communication means, vehicle motor control apparatus according to any one of claims 1 to 4, characterized in that transmits a detection result of the battery voltage to the drive controller. The on-vehicle motor control device according to claim 1 , wherein the booster circuit unit transmits a detection result of the battery current to the drive control unit via the communication unit . The in-vehicle motor control according to claim 6 , wherein the drive control unit controls a current amount supplied to the winding of the motor based on a detection result of the battery current transmitted from the booster circuit unit. apparatus.   The on-vehicle motor control device according to any one of claims 1 to 7, wherein the drive control unit drives and controls a three-phase motor.   The on-vehicle motor control device according to claim 8, wherein the three-phase motor is a brushless motor.   9. The drive control unit detects a rotational position of a rotor in the three-phase motor using a resolver arranged in the three-phase motor, and performs PWM control based on the rotational position. Or the vehicle-mounted motor control apparatus of 9.   The on-vehicle motor control device according to any one of claims 1 to 10, wherein the drive control unit includes a power supply circuit for generating a control power supply from a battery voltage. An in-vehicle motor control device according to any one of claims 1 to 11,
A power steering device that assists driving of a steering wheel by output torque of a motor.

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