JP2005039943A - Motor drive control method and motor drive control circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive control method and a motor drive control circuit capable of dealing with a plurality of speed indication signals and high in versatility. <P>SOLUTION: The speed indication signal input from the outside is converted to a signal suitable for the input of a microcomputer 2 in a communication circuit 1 and input to the microcomputer 2. The kind of the speed indication signal is determined, and a control signal that corresponds to the determined signal is generated and outputted to a motor drive circuit 3, to make a brushless motor 4 rotatively driven by the motor drive circuit 3. The motor drive control method and the motor drive control circuit can thus deal with a plurality of kinds of the speed indication signals. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to drive control of a motor, and more particularly to improvement of versatility of a motor drive control circuit used for rotational drive of a blower fan or the like in a vehicle air conditioner.

Conventionally, for example, a brushless motor or the like is mainly used for driving a rotating body such as a blower fan of a vehicle air conditioner. The drive control circuit is configured to be applied with a speed instruction signal for designating the speed of the motor from the outside and to control the drive of the motor based on the input signal, and various types have been proposed. (For example, refer to Patent Document 1).
A typical example of a speed instruction signal input to such a motor drive control circuit is a conventionally used PWM (Pulse Width Modulation) signal. In recent years, various information devices have been installed in vehicles. Communication signals based on various communication protocols typified by LIN (Local Interconnect Network) for in-vehicle LANs, etc., which have been developed along with the realization of the above, have been used.
FIG. 4 shows a basic configuration example of the motor drive control circuit when the speed instruction signal is a PWM signal, and FIG. 5 shows a basic configuration example of the motor drive control circuit when the speed instruction signal is a LIN communication signal. These conventional circuit examples will be described below with reference to FIG.

First, when a PWM signal is used as the speed instruction signal, the PWM signal is output from, for example, the control circuit 101 of the vehicle air conditioner using the open collector transistor 101a, and the motor drive control circuit Sa. Is input to a voltage conversion circuit (noted as “V-CON” in FIG. 4) 11 provided in the input stage of FIG. The voltage level is converted and input to the microcomputer 12.
In the microcomputer 12, the on / off period of the input PWM signal is determined, and a drive control signal for the brushless motor 14 corresponding to the determination result is output to the motor drive circuit 13. In the motor drive circuit 13, a drive current is supplied to the brushless motor 14 in accordance with a drive control signal from the microcomputer 12.

On the other hand, when the LIN communication signal is used, first, the LIN communication signal is output from the control circuit 102 of the vehicle air conditioner using the open collector transistor 102a as in the case where the PWM signal is used. Therefore, the signal is input to a communication circuit (indicated as “COM” in FIG. 5) 15 provided at the input stage of the motor drive control circuit Sb. Here, the same components as those shown in FIG. 4 are denoted by the same reference numerals.
The communication circuit 15 converts the input LIN communication signal into a voltage suitable for input to the microcomputer 16 while receiving timing control from the microcomputer (indicated as “CPU” in FIG. 5) 16 and outputs the voltage. It is something like that.

Here, the microcomputer 16 used for the LIN communication is provided with a reception port (indicated as RXin in FIG. 5) and a timer port (indicated as “Timer” in FIG. 5). The LIN communication signal is input to each port at the same time. First, at the receiving port, it is determined whether the input signal is a signal conforming to the LIN protocol, determination of communication start, etc., and a signal for determining the rotation speed of the brushless motor 14 is input. When it is determined, the rotation speed is determined from the input serial data signal at the timer port. Next, a drive control signal of the brushless motor 14 corresponding to the determination result of the rotational speed at this timer port is output to the motor drive circuit 13, and the motor drive circuit 13 responds to the drive control signal from the microcomputer 16. Thus, a drive current is supplied to the brushless motor 14. The motor drive circuit 13 has basically the same configuration as that shown in FIG.
Thus, conventionally, the motor drive control circuit is usually provided with a configuration corresponding to the format of the input speed instruction signal.

JP 2000-350484 A

However, it is economical to design and manufacture a drive circuit for each type of speed instruction signal, contrary to the universal demands of manufacturers such as reduction of duplication labor and reduction of manufacturing cost due to common design and manufacturing processes. There was a problem that was not.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a motor drive control method and a motor drive control circuit with high versatility that can handle a plurality of speed instruction signals.

In order to achieve the above object of the present invention, a motor drive control circuit according to the present invention includes:
A motor drive control circuit configured to control energization of the motor based on a speed instruction signal that determines the rotation state of the motor input from the outside,
Conversion means for converting the signal level of the speed instruction signal;
Drive means for energizing the motor in response to an externally input control signal;
Determine the type of the speed instruction signal input via the conversion means, determine the rotational speed of the motor from the externally input speed instruction signal according to the determined speed instruction signal type, And a control processing means for generating and outputting a control signal for the drive means in accordance with the determination result.
According to such a configuration, the type of the speed instruction signal is determined, and a control signal corresponding to the determined type of signal is generated and output. It is not necessary to provide an input stage circuit, and it is possible to provide a highly versatile motor drive control method and motor drive control circuit that can handle a plurality of speed instruction signals.

  According to the present invention, since it can respond to a plurality of speed instruction signals, it is possible to provide a highly versatile and relatively inexpensive motor drive control circuit.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.
The members and arrangements described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention.
First, a configuration example of the motor drive control circuit S in the embodiment of the present invention will be described with reference to FIG.
The motor drive control circuit S includes a communication circuit (indicated as “COM” in FIG. 1) 1, a microcomputer (indicated as “CPU” in FIG. 1) 2, and a motor drive circuit (indicated as “DRV in FIG. 1). 3) as a main component, and as described later, for example, a brushless motor 4 having a known / known configuration as a blower motor of a vehicle air conditioner is driven. It is what has become.

The motor drive control circuit S executes a motor drive control by the microcomputer 2 as will be described later, and outputs a PWM signal and a LIN as a speed instruction signal input from the outside for instructing the rotation speed and operation stop of the brushless motor 4. The (Local Interconnect Network) communication signal (or K-LINE communication signal) can be handled.
LIN is a serial communication protocol advocated by several European automakers for in-vehicle LAN (Local Area Network), and can be said to be a so-called defect standard (de facto standard). Since the details are publicly known and well known, the description here will be omitted. K-LINE is a high-level communication protocol mainly used for electrical failure diagnosis of various electronic devices mounted on the vehicle, but it can also be used to control the rotation of brushless motors. Since the level of the electric signal to be performed is basically the same as that of LIN, for example, it is possible to control by K-LINE in a circuit provided with hardware such as a line of LIN specification. The details of K-LINE itself are publicly known and well-known as defined in ISO9141, and detailed description thereof will be omitted here.
These PWM signal and LIN communication signal (or K-LINE communication signal) are output from the control circuits 101 and 102 of the vehicle air conditioner using the open collector transistors 101a and 102a, for example. 1 (see FIG. 1). In LIN and K-LINE, a bus line system is usually used for signal transmission, and the connection between the control circuits 101 and 102 and the communication circuit 1 in FIG. It is what is said.

The communication circuit 1 has basically the same configuration as that used in a motor drive control circuit (see FIG. 5) that has been conventionally configured to support only a LIN communication signal as a speed instruction signal.・ It is well known. That is, the communication circuit 1 converts a speed instruction signal input from the outside into a voltage suitable for input to the microcomputer 2 while receiving timing control from the microcomputer 2 and outputs the converted voltage. is there.
Here, the PWM signal and the LIN communication signal (or K-LINE communication signal) are both in the same voltage range as long as they are compared at the voltage level. That is, FIGS. 3A and 3B show specific signal waveform examples. The following description will be made with reference to FIG. This is an on / off pulse signal of 100 Hz to 1000 Hz (10 ms to 1 ms). The duty ratio of the on / off time is set according to the desired rotation speed of the brushless motor 4 (see FIG. 3A).

On the other hand, the LIN communication signal is a serial pulse signal having a transmission rate of approximately 10 kbps to 20 kbps (100 μs to 50 μs) (see FIG. 3B). Each signal is turned on / off between 0v and 12v (see FIGS. 3A and 3B). Since the high-side voltage 12v is a battery voltage of the vehicle, when the battery voltage is other than 12v, the voltage is replaced with 12v.
Because of the commonality of both signals, there is no problem even if the communication circuit 1 originally used in the input stage of the motor drive control circuit for the LIN communication signal is used for the input of the PWM signal. Even if it is an input signal, it is converted to a voltage level suitable for the input of the microcomputer 2 and input to the microcomputer 2.

The microcomputer 2 has basically the same hardware configuration as that used in a motor drive control circuit (see FIG. 5) that has been conventionally configured to be compatible only with a LIN communication signal as a speed instruction signal. Although it is a publicly known device having a configuration, it differs from the conventional one in that motor drive control as will be described later is executed, and can now perform operations and functions that are not realized by the conventional motor drive control circuit. It is what.
In the motor drive circuit 3, for example, a plurality of transistors are connected in a so-called bridge, and the plurality of transistors are turned on / off in accordance with a control signal from the microcomputer 2 to control energization to the brushless motor 4. These are known and well-known ones, and basically have the same constitution as that of the conventional circuit.
Since the brushless motor 4 has a known and well-known configuration, a detailed description thereof will be omitted here. The brushless motor 4 is provided with, for example, a rotor rotational position detector using a Hall element or the like for detecting the rotor position, and an output signal thereof is output. However, in FIG. 1, illustration of the output signal is omitted. The output signal of the rotational position detector is input to the microcomputer 2 and used for generating a control signal to the motor drive circuit 3.

Next, motor drive control executed by the microcomputer 2 in the above configuration will be described with reference to the flowchart shown in FIG.
First, when processing is started, a speed instruction signal is first taken into (inputted) into the microcomputer 2 via the communication circuit 1 (see step S102 in FIG. 2).
Here, the microcomputer 2 is provided with a receiving port (denoted as RXin in FIG. 1) and a timer port (denoted as “Timer” in FIG. 1) as in the prior art. The speed instruction signals that have passed through are input to the respective ports at the same time.

Next, it is determined whether or not the input speed signal is suitable for some communication protocol (see step S104 in FIG. 2). That is, in the embodiment of the present invention, it is determined whether or not the speed instruction signal input on the receiving port side of the microcomputer 2 is based on some communication protocol, and is adapted to the communication protocol. If it is determined (in the case of YES), the process proceeds to step S106 described below. If it is determined that the communication protocol is not satisfied (in the case of NO), the process proceeds to step S112 described later. , Each will proceed.
In step S106, in response to the determination that the speed instruction signal is based on some communication protocol in the previous step S104, it is determined whether or not the communication protocol is LIN. If it is determined (YES), the process proceeds to step S108, and the operation of the brushless motor 4 using the speed instruction signal as the LIN communication signal is started. On the other hand, when it is determined in step S106 that the speed instruction signal is not LIN (in the case of NO), the operation of the brushless motor 4 is started assuming that the speed instruction signal is K-LINE (FIG. 2 step S110).
And after step S108 or step S110 is performed, it will progress to the process of step S114 mentioned later.

On the other hand, if it is determined in step S104 that the speed instruction signal does not conform to the communication protocol (in the case of NO) and the process proceeds to step S112, it is assumed that the speed instruction signal is a PWM signal. The operation of the brushless motor 4 is started, and the process proceeds to step S114.
In step S114, the speed instruction signal is again input to the microcomputer 2 via the communication circuit 1. Next, in step S116, whether or not the input speed instruction signal instructs operation is described. For example, it is determined whether or not the speed instruction signal is a signal for instructing the rotation speed and what rotation speed is instructed.
Specifically, first, the determination in step S116 is performed on the timer port side of the microcomputer 2. That is, when the input speed instruction signal is determined to be a PWM signal (see step S112 in FIG. 2), the on / off time of the PWM signal indicates the rotation speed of the brushless motor 4. Therefore, the on / off time is detected at the timer port. When the speed instruction signal is determined to be a LIN or K-LINE communication signal (see steps S108 and S110 in FIG. 2), the rotation speed is represented as a serial bit signal in a predetermined format. Therefore, the serial data is determined on the timer port side.

When it is determined that the speed instruction signal instructs driving (in the case of YES), motor operation is performed based on the driving instruction (see step S118 in FIG. 2), and then the previous step The process returns to S114 and the subsequent processing is repeated. That is, when the speed instruction signal is a PWM signal, a control signal corresponding to the on / off time determined by the timer port is output to the motor drive circuit 3, and the motor drive circuit 3 responds to the control signal. That is, energization of the drive current corresponding to the rotation speed determined by the on / off time of the PWM signal is performed.
When the speed instruction signal is a LIN or K-LINE communication signal, a control signal corresponding to the detected serial bit data is output to the motor drive circuit 3, and the motor drive circuit 3 responds to the control signal. That is, energization of the drive current corresponding to the rotational speed determined by the serial bit data is performed.

On the other hand, if it is determined in step S116 that the speed instruction signal has not instructed driving (in the case of NO), the motor operation is stopped, and the process returns to the previous step S102, and the above-described series of steps. The process will be repeated again. In the embodiment of the present invention, the instruction to stop the operation by the speed instruction signal is made in a state in which the signal level of any of the PWM signal, the LIN or the K-LINE communication signal is continuously maintained at 12v. It is like that.
In the above configuration example, the driving example of the brushless motor 4 has been described. However, the motor drive control method according to the present invention is not necessarily limited to the brushless motor, and is basically applicable to a motor with a normal brush. Is equally applicable. That is, even if the type of motor is changed and the configuration of the motor drive circuit 3 is changed accordingly, if the control signal from the microcomputer 2 has the same specification, the type of speed instruction signal as described above. The motor can be driven and stopped by the determination, the determination of the driving instruction according to the determination result, and the output of the control signal to the motor drive circuit 3 according to the determined driving instruction.

  In the above configuration example, it is assumed that any of the PWM signal, the LIN communication signal, and the K-LINE communication signal is input as the speed instruction signal. However, it is not necessary to be limited to these signals. Of course, other types of signals may be used. In this case, the determination criteria in steps S104, S106, and S116 in FIG. 2 are changed to those corresponding to the signals, and the operations in S108, S110, and S112 are changed according to the respective signals. do it.

It is a block diagram which shows the structural example of the motor drive control circuit in embodiment of this invention. It is a flowchart which shows the process sequence of the motor drive control performed by the microcomputer of the motor drive control circuit shown by FIG. FIG. 3A is a waveform diagram illustrating a waveform example of a speed instruction signal, FIG. 3A is a waveform diagram in the case of a PWM signal, and FIG. 3B is a waveform diagram in the case of a LIN communication signal. It is a block diagram which shows the structural example of the conventional circuit in case a speed instruction | indication signal is a PWM signal. It is a block diagram which shows the structural example of the conventional circuit in case a speed instruction | indication signal is a LIN communication signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Communication circuit 2 ... Microcomputer 3 ... Motor drive circuit 4 ... Brushless motor

Claims (6)

  Determine the type of the speed instruction signal that determines the rotational state of the externally input motor, determine the rotational speed of the motor from the externally input speed instruction signal according to the determined type of the speed instruction signal, A drive control method for a motor, wherein the motor is driven at the determined rotational speed. It is determined whether or not the speed instruction signal that determines the rotation state of the externally input motor conforms to a predetermined communication protocol. If it is determined that the speed instruction signal conforms to a predetermined communication protocol, the communication While determining the rotational speed of the motor from the speed instruction signal based on a protocol, and driving the motor to the determined rotational speed,
When it is determined that the speed instruction signal does not conform to a predetermined communication protocol, the speed instruction signal is determined to be a PWM signal, and the on / off time is determined, and the speed instruction signal is determined according to the determination result. A motor drive control method characterized by driving a motor.   3. The motor drive control method according to claim 1, wherein the speed instruction signal is any one of a PWM signal, a LIN communication signal, and a K-LINE communication signal. A motor drive control circuit configured to control energization of the motor based on a speed instruction signal that determines the rotational state of the motor input from the outside,
Conversion means for converting the signal level of the speed instruction signal;
Drive means for energizing the motor in accordance with an externally input control signal;
Determine the type of the speed instruction signal input through the conversion means, determine the rotational speed of the motor from the speed instruction signal input from the outside according to the determined type of speed instruction signal, Control processing means for generating and outputting a control signal to the drive means according to a determination result;
A motor drive control circuit comprising: The control processing means uses a microcomputer, and the microcomputer
When it is determined whether or not the speed instruction signal for determining the rotation state of the motor input via the conversion means conforms to a predetermined communication protocol, and if it is determined to conform to the predetermined communication protocol Determines the rotational speed of the motor from the speed instruction signal based on the communication protocol, and generates and outputs a control signal to the drive means corresponding to the determined rotational speed,
When it is determined that the speed instruction signal does not conform to a predetermined communication protocol, the speed instruction signal is determined to be a PWM signal, the on / off time is determined, and the drive corresponding to the determination result is determined. 5. The motor drive control circuit according to claim 4, wherein the motor drive control circuit is configured to generate and output a control signal to the means.   6. The motor drive control circuit according to claim 5, wherein the speed instruction signal is any one of a PWM signal, a LIN communication signal, and a K-LINE communication signal.

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