JP3218902B2 - Multiplex communication device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplex communication device used for vehicles and the like, and more particularly to a multiplex communication device used for controlling motors of electric components mounted on a vehicle.

[0002]

2. Description of the Related Art In a conventional vehicle electrical system, when a control unit for processing motor control data and an actuator having a motor are installed separately, a motor drive and a rotation angle monitor are provided between the control unit and the actuator. For this reason, it was wired by a plurality of signal lines. However, when the number of actuators increases with the sophistication of the vehicle, the number of wirings between the control unit and the actuator as communication control devices increases, causing problems such as poor layout and insufficient terminals on the control unit side. Has been introduced.

As such a conventional multiplex communication device, there is, for example, one shown in FIG. Here, a plurality of actuators 602 are connected to the control unit 601 by a communication line 603. The control unit 601 includes a microcomputer 60 that performs data processing.
4 and a transmission circuit 605. The microcomputer 604 is
The address of the actuator to be controlled and the target position of the motor are encoded, and the encoded data is transmitted to the transmission circuit 60.
5 and output on the communication line 603.

Each actuator 602 has a receiving circuit 606 for receiving a signal on a communication line 603, a transmission start detecting circuit 607 and a decoder 60 connected thereto.
8 and a sequence counter 609 are provided. The sequence counter 609 counts up each time the received signal rises or falls, and generates a decode timing of the received data. Transmission start detection circuit 6
07 detects the start of transmission of the control unit 601, and resets the sequence counter 609. Then, the decoder 608 decodes (decodes) the encoded data obtained by the receiving circuit 606 based on the output value of the sequence counter 609.

A decoder 608 has a D / A converter 610 for converting its output into an analog value and a control circuit 61.
2, a drive circuit 613 is connected, and the drive circuit drives the motor 617. The motor 617 has a PBR (Potenti) that outputs its rotational position as a voltage value.
o Balance Resistor 618 is provided, and the output of the PBR is input to the control circuit 612. The control circuit includes the output of the PBR 618 and the D / A converter 61
The normal rotation / reversal / stop of the motor 617 is determined according to the output of 0.

Normally, the procedure by which the control unit 601 controls the motor 617 is as follows. First, the microcomputer 604 of the control unit 601 encodes the address of the actuator 602 having the motor 617 to be controlled and the target position of the motor, and outputs the encoded data to the communication line 603 through the transmission circuit 605. In the actuator 602, the transmission start detection circuit 607 detects that the output of data on the communication line 603 has been started via the reception circuit 606, and resets the sequence counter 609.

[0007] The decoder 608 decodes the received signal based on the output value of the sequence counter 609 which counts up, and determines whether or not the signal is data addressed to itself based on address information included in the received signal. . When recognizing that the received signal is data addressed to itself, the decoder 608 outputs the target position data included in the received signal as a digital value. Control circuit 61
2 indicates that the output of the PBR 618 indicating the current position of the motor is D
The rotation direction of motor 617 is determined so as to match the target position converted into an analog value by A / A converter 610. After the drive circuit 613 boosts the signal of the control circuit 612 by the boost circuit 615, the H-bridge circuit 61
6, the motor 617 is driven to rotate.

However, even if the drive of the motor 617 is terminated when the target position and the current position match, the control circuit 612 reverses the motor to make it coincide with the target position because the motor runs over the target position due to overrun due to inertia. And By this repetition, a vibration phenomenon called so-called hunting occurs, which causes abnormal noise depending on the applied system. In order to prevent this hunting, conventionally, a method of setting a width larger than the overrun with respect to the target position as the hysteresis and stopping the rotation of the motor when the current position is within the hysteresis is adopted.

However, since "hysteresis width = stop accuracy", if the stop accuracy required by the system is narrower than this hysteresis width, as a measure, the rotational speed of the motor is reduced by duty control to reduce the amount of overrun. Accordingly, the hysteresis width is reduced.

FIG. 7 shows a multiplex communication apparatus having such a conventional duty-controlled motor control unit. This device is the same as that shown in FIG. 6 up to the point where the signal from the control unit is processed in the actuator 602 ′ after the receiving circuit 606 and input to the control circuit 612. The actuator 602 ′ is provided with a pulse generation circuit 611 in addition to this configuration, and its output masks the output of the control circuit 612 by the AND gate 614. Therefore, the input signal received by the H-bridge circuit 616 of the drive circuit 613 becomes a pulse, and the motor 61
7 is changed by the duty ratio of the pulse output from the pulse generation circuit 611.

[0011]

However, in such a conventional multiplex communication apparatus having a motor control unit based on duty control, an oscillation circuit utilizing a time constant of a capacitor and a resistor must be provided as a pulse generation circuit. Was. Therefore, when a pulse having a relatively large cycle is required, a large-capacity capacitor is required. When the electronic circuit section of the actuator is made into a custom IC, a capacitor must be externally attached, which leads to an increase in cost and cost. There has been a problem that a terminal shortage of the custom IC is caused.

When a logic oscillation circuit is provided in the actuator, a necessary pulse can be obtained by dividing the clock, but when a pulse having a large cycle is required, It is necessary to form a frequency dividing circuit with a large number of flip-flops, which increases the circuit scale and increases the cost. Furthermore, if the pulse width or cycle is changed when changing the motor specifications or diverting it to another system, a circuit change is required. There is a problem that a custom IC must be prepared. Therefore, the present invention has been made in view of the above-mentioned conventional problems. In a multiplex communication device used for motor control for performing duty control, a large-capacity capacitor or circuit for generating a pulse for duty control is provided. It is an object of the present invention to provide a multiplex communication apparatus that does not require an increase in scale and that can easily change the pulse width and cycle.

[0013]

SUMMARY OF THE INVENTION Therefore, the present invention provides a first method.
In the multiplex communication apparatus in which the communication control means of the above and the second communication control means provided with the motor are connected by a communication line, the first communication control means performs control including a target position of the motor based on a predetermined transmission format. A second communication control unit that outputs the data as a pulse signal on the communication line, the second communication control device receiving means for receiving the pulse signal on the communication line, a decoder for decoding a reception signal obtained by the reception means to obtain a target position, Pulse extraction means for extracting a predetermined pulse from the reception signal obtained by the means, position detection means for outputting the current position of the motor, and motor control means for controlling the motor so that the current position matches the target position. The motor control means controls the duty of the motor by the pulse extracted by the pulse extraction means.

In particular, the second communication control device includes a sequence counter that counts pulses of the received signal to generate a decode timing, the decoder performs decoding based on the output of the sequence counter, and the pulse extracting means includes: It is preferable to extract the pulse of the received signal when the sequence counter indicates a predetermined value.

[0015] The duty ratio can be controlled by the first communication control device changing the width of the predetermined pulse in the transmission format. Alternatively, the first communication control device is the second communication control device.
By changing the communication interval to the communication control device of
The duty ratio can be controlled. Further, the pulse extracting means may extract a predetermined pulse in a received signal irrespective of an address to be transmitted by the first communication control device.

[0016]

In the second communication control device, the receiving means fetches a pulse signal from the communication line, and the decoder obtains the target position of the motor from the received signal. Further, the pulse extracting means extracts a predetermined pulse from the received signal. The position detection means outputs the current position of the motor, and the motor control means controls the motor so that the current position matches the target position. At this time, the motor control means controls the duty of the motor by the pulse extracted by the pulse extraction means.
Since a pulse used for duty control of the motor is extracted from the communication signal, an external capacitor for a pulse generating circuit and a large-scale clock frequency dividing circuit are not required, and the duty ratio can be changed by software.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. A control unit 101 as first communication control means is connected to a plurality of actuators 102, 102,... As second communication control means via a communication line 103. The control unit 101 is a microcomputer 1 that outputs a clock signal and performs data processing.
And a transmission circuit 105 that outputs a clock signal and a data signal from the microcomputer 104 to the communication line 103.

Each actuator 102 has a receiving circuit 106 for receiving a signal on the communication line 103, a transmission start detecting circuit 107 connected to the receiving circuit 106, and a decoder 10
8 and a sequence counter 109 are provided. The sequence counter 109 counts up each time the received signal rises or falls, and generates a decode timing of the received data. Transmission start detection circuit 1
In step 07, the start of transmission by the control unit 101 is detected, and the sequence counter 109 is reset. Then, the decoder 108 decodes the encoded data obtained by the receiving circuit 106 based on the output value of the sequence counter 109.

The output of the decoder 108 is converted into an analog value by a D / A converter 110 and input to a control circuit 112. The output of the control circuit 112 is an AND circuit 114
The driving circuit 113 drives the motor 117 via the H-bridge circuit 116 after boosting the signal of the control circuit 112 by the boosting circuit 115. The motor 117 has a PBR (Potentio Balance Res) which outputs the rotational position as a voltage value.
istor) 118, and the output of the PBR is input to the control circuit 112. The control circuit determines forward / reverse / stop of the motor 117 according to the output of the PBR 118 and the output of the decoder 108 via the D / A converter 110.

The actuator 102 is further provided with a pulse extracting circuit 111 between the receiving circuit 106 and the sequence counter 109 and the AND circuit. The pulse extracting circuit 111 includes an AND circuit, and outputs a pulse received by the receiving circuit 106 to the AND circuit when the value of the sequence counter 109 reaches a predetermined value.

The communication code of the signal transmitted from the control unit 101 to the communication line has H / L defined by two types of pulses having different amplitudes. Then, as shown in FIG. 2A, 2-bit binary data is represented by three pulse arrays. For example, if HHH is "00",
HLH is “01”, HHL is “10”, HLL is “1”
1 ". In addition, to clarify the start of the transmission,
As shown in FIG. 2B, four pulse trains “HLLL” are used as transmission start codes.

The microcomputer 1 of the control unit 101
04 is the address of the actuator 102 and the motor 117 to be transmitted according to a predetermined transmission format.
And outputs it on the communication line 103 through the transmission circuit 105. FIG. 3 shows an example of the transmission format. Following the transmission start code 301, the address 302 of the actuator to be transmitted is transmitted in 2 bits, the data 303 representing the target position of the motor is transmitted in 8 bits, and finally the duty is transmitted. One pulse 304 defining the ON time during control is added. Here, the sequence counter 109 outputs a signal to the pulse extraction circuit 111 when the count value becomes Fh.

Next, the operation of the embodiment constructed as described above will be described. FIG. 4 shows an example of an address = 0 and a target position data = 5Bh (01010110).
1B is a timing chart in the case where 1b) is transmitted from the control unit 101. 4A shows the signal potential transmitted over the communication line, FIG. 4B shows the count state of the sequence counter 109, FIG. 4C shows the output of the transmission start detection circuit 107, FIG. 4D shows the output of the sequence counter 109, and FIG. e) shows the output of the pulse extraction circuit 111, and (f) shows the output of the decoder 108.

First, when transmission is started from the control unit 101, in the actuator 102, when the transmission start detection circuit 107 detects the transmission start signal 301 via the reception circuit 106, it outputs as shown in FIG. Is issued, and the sequence counter 109 is reset. Thereafter, the sequence counter 109 counts up at each falling edge of the received signal pulse as shown in (b). Based on the output value of the sequence counter 109 that counts up, the decoder 108 recognizes which position in the format the pulse being received falls on and decodes the received signal.

When the address portion of the received signal matches its own address, the decoder as shown in FIG.
After receiving the data section 303, the target position data is output as a digital value. The control circuit 112 determines the rotation direction of the motor 117 so that the output of the PBR 118 indicating the current position of the motor matches the target position converted into an analog value by the D / A converter 110.

The sequence counter 109 outputs a signal to the pulse extraction circuit 111 when the value corresponding to the end of the format, that is, the count value is Fh, as shown in FIG. And as shown in (e). The pulse extraction circuit 111 outputs a pulse having the same width as the ON time definition pulse 304 which is the last pulse in the transmission format. This pulse extraction circuit is AN
Since it is connected to the input of the D circuit 114, the output of the control circuit 112 is masked by the output of the pulse extraction circuit, and is input to the drive circuit for a controlled duration. This allows
The duty of the motor 117 is controlled. The above-described pulse extraction circuit 111 constitutes the pulse extraction means of the invention, the control circuit 112, the AND circuit 114 and the drive circuit 113 constitute the motor control means, and the PBR 118 constitutes the position detection means.

In this embodiment, the pulse used for the duty control of the motor is extracted from the communication signal as described above. Therefore, a large-capacity external capacitor for the pulse generation circuit, a large-scale This eliminates the need for a clock frequency dividing circuit and the like, and has an effect that the duty control can be performed at a small size and at low cost. In this duty control, the width of the ON time definition pulse 304 is the ON time when the motor is driven, and the control unit 1
The communication interval (transmission cycle) of 01 is the cycle as it is. Since the control unit 101 generates the transmission code by the microcomputer 104, the communication interval or the time such as the ON time defining pulse width can be arbitrarily set by the communication control software. Both can be controlled together. As described above, since the duty ratio can be changed by software, there is no need to change the circuit when changing the motor specifications or diverting the system to another system. are doing.

Next, a second embodiment of the present invention will be described. In this embodiment, the output from the sequence counter to the pulse extraction circuit 111 is performed irrespective of the address. FIG. 5 is a timing chart, in which (a) shows a signal sequence transmitted on a communication line,
(B) shows the output of the pulse extraction circuit 111, and (c) shows the output of the decoder 108.

Here, as shown in (a), when transmissions to the actuators having different addresses are sequentially performed, for example, after receiving the target position data addressed to itself at the actuator of address = 0, While the control unit 101 is transmitting to another actuator, as shown in (b), a pulse is also extracted from a transmission signal addressed to another actuator. The target position data of the motor is maintained as it is, and the next transmission signal addressed to itself is decoded and updated as shown in (c).

As a result, in this embodiment, it is possible to perform duty control with a short pulse period without waiting for the next transmission signal addressed to itself. Also in this case, since the communication interval of the control unit becomes the cycle of the duty control, these times can be arbitrarily set by communication control software.
It is also possible to control both the N time definition pulse widths together.

[0031]

As described above, according to the present invention, in a multiplex communication apparatus in which first communication control means and second communication control means are connected by a communication line to perform motor control, a pulse used for motor duty control is transmitted. Because it is configured to extract from the signal, an external capacitor for the pulse generation circuit,
A large-scale clock frequency dividing circuit is not required, the size is small, and the duty control can be performed without increasing the cost.
Further, since the duty ratio can be changed by software, there is no need to change the circuit even when changing the specifications of the motor or diverting to another system, and the custom IC can be used as it is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is an explanatory diagram showing communication codes.

FIG. 3 is a diagram illustrating an example of a transmission format of a control unit.

FIG. 4 is a timing chart showing the operation of the embodiment.

FIG. 5 is a timing chart showing a second embodiment.

FIG. 6 is a diagram showing a conventional example.

FIG. 7 is a diagram showing another conventional example.

[Explanation of symbols]

Reference Signs List 101 Control unit (first communication control means) 102 Actuator (second communication control means) 103 Communication line 104 Microcomputer 105 Transmission circuit 106 Receiving circuit (receiving means) 107 Transmission start detection circuit 108 Decoder 109 Sequence counter 110 D / A Converter 111 Pulse extraction circuit (pulse extraction means) 112 Control circuit 113 Drive circuit 114 AND circuit 115 Boost circuit 116 H bridge circuit 117 Motor 118 PBR (Position detection means) 601 Control unit 602, 602 'Actuator 603 Communication line 604 Microcomputer 605 Transmission Circuit 606 Receiving circuit 607 Transmission start detecting circuit 608 Decoder 609 Sequence counter 610 D / A converter 611 Pulse generating circuit 612 Control circuit 613 Dynamic circuit 614 the AND gate 615 the booster circuit 616 H-bridge circuit 617 a motor 618 PBR

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-227841 (JP, A) JP-A-6-6868 (JP, A) JP-A-5-161394 (JP, A) JP-A-6-868 76607 (JP, A) Japanese Utility Model Hei 3-44948 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H04Q 9/00-9/16 H02P 7/00

Claims (5)

(57) [Claims] 1. In a multiplex communication apparatus in which a first communication control means and a second communication control means having a motor are connected by a communication line, the first communication control means is provided based on a predetermined transmission format. Outputting control data including a target position of the motor as a pulse signal on a communication line;
Communication control device, receiving means for receiving a pulse signal on the communication line, a decoder for decoding the received signal obtained by the receiving means to obtain a target position, and a predetermined signal among the received signals obtained by the receiving means Pulse extracting means for extracting a pulse, position detecting means for outputting a current position of the motor, and motor controlling means for controlling the motor so that the current position coincides with the target position, the motor controlling means comprising: And a duty control of the motor based on the pulse extracted by the pulse extracting means. 2. The duty ratio according to claim 1, wherein the first communication control device controls the duty ratio by changing a width of the predetermined pulse in the transmission format. Multiplex communication device. 3. The duty ratio is controlled by changing a communication interval of the first communication control device to the second communication control device. The multiplex communication device according to claim 1. 4. The apparatus according to claim 1, wherein the second communication control device includes a sequence counter for counting a pulse of the received signal to generate a decode timing, wherein the decoder performs decoding based on an output of the sequence counter, 4. The multiplex communication apparatus according to claim 1, wherein the extraction unit extracts a pulse of the reception signal when the sequence counter indicates a predetermined value. 5. The apparatus according to claim 1, wherein the pulse extracting means extracts a predetermined pulse in the received signal irrespective of an address to be transmitted by the first communication control device. 5. The multiplex communication device according to 1, 2, 3 or 4.