JPH08188166A - Electric powered steering controller - Google Patents

Abstract

PURPOSE: To reduce the number of signal lines and connectors so as to reduce cost by providing a connector at a tip of branch point of a signal line of a subtorque sensor and a control section, connecting the tip with a transmission terminal and a receive terminal of an external communication device, and performing reading of the subtorque sensor and transmission and reception with time difference. CONSTITUTION: A subtorque sensor 4 is connected to a control section 1 through a signal line 14 and a connector 8, and an external communication device 5 is connected to the signal line 14 through a signal line 14a and a connector 7. The signal line 14 is branched at a branch point 21 and connected with the signal line 14a through the connector 7. Moreover, in the communication device 5, the signal line 14a is branched into a signal line 14b at a branch point 22. A microcomputer 6 in the communication device 5 has a transmission terminal 28 and a receive terminal 29 to perform transmission and reception alternately. Since the same signal line 14 is used in reading of the subtorque sensor 4 and transmission and reception from a transmission device 5, they are performed by staggering time so that three kinds of signals do not affect one another.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric power steering device, and more particularly to a control device suitable for use in a steering torque sensor circuit and a communication circuit.

[0002]

2. Description of the Related Art A conventional electric power steering control apparatus shown in FIG. 6 detects a steering torque and outputs a signal, a main torque sensor 3, a sub torque sensor 4, a control unit 1,
It includes a communication device 5, a motor 11, and a battery 12. The control unit 1 includes a power supply circuit 9, a drive circuit 10, and a microcomputer 2 that controls the entire system and detects an abnormality, and the communication device 5 knows the operating status of the system.
A microcomputer 6 for transmitting and receiving signals is provided to change the operating condition. Then, for the power assist of the steering, the main torque sensor 3 detects the steering torque and outputs a signal corresponding to the torque. The control unit 1 supplies a current corresponding to the signal from the main torque sensor 3 from the battery 12 to the motor 11. The sub-torque sensor 4 outputs a voltage in association with the main torque sensor 3 according to the steering torque, and monitors the relationship between the two torque sensors 3 and 4 by the control unit 1 to detect an abnormality of the main torque sensor 3. Is. In addition, the communication device 5 and the control unit 1
Are connected by dedicated connectors 18 and 19 to the dedicated signal lines 15 and 16, and information is transmitted by a pulse train. It should be noted that the communication device 5 and the control unit 1 are not always connected, but are connected to each other when the operating status is confirmed or the operating characteristics are changed at the time of failure, system development, or the like. Is.

[0003]

SUMMARY OF THE INVENTION In such a device,
For connection with the control unit 1, the main torque sensor 3 uses the signal line 13 and the connector 20, the sub torque sensor 4 uses the signal line 14 and the connector 8, and the communication device 5 uses the signal lines 15 and 16 and the connectors 18 and 19. It is connected. As described above, since the signal line and the connector are separate from each other and are large in number, parts and manufacturing costs are high. In particular, the communication device 5 is not always connected to the control unit 1 but is connected only when necessary, but the connectors 18 and 19 and the signal lines 15 and 16 that are not often used are always prepared. It will be. Therefore, an object of the present invention is to provide a signal line,
The aim is to reduce the number of connectors and reduce costs.

[0004]

The present invention is directed to an electric motor for power assisting steering, a main torque sensor for detecting steering torque of the steering, and a sub-torque sensor for outputting a voltage in cooperation with the main torque sensor. And a current value corresponding to the signal of the main torque sensor is supplied to the motor, and the main torque sensor is monitored for abnormalities by the relationship between the sub torque sensor and the main torque sensor. In an electric power steering control device including a control unit having a function of communicating information with an external communication device, a branch is provided in a signal line connecting the sub torque sensor and the control unit, and a connector is provided at a branch destination. The signal line connected to this connector is further branched, and each is connected to the transmission terminal of the external communication device. Connected to signal terminal, a read of the sub torque sensor, and the transmission and reception of the communication device, and performs with a time difference.

[0005]

The steering torque is detected by the main torque sensor, and an electric current corresponding to the detected value is supplied to the electric motor by the command of the control unit to power assist the steering. The sub-torque sensor outputs a voltage in conjunction with the main torque sensor, and the control unit monitors the relationship with the main torque sensor, detects an abnormality in the main torque sensor, and avoids danger. An external communication device is connected to the connector as necessary to perform transmission / reception, but transmission and reception are performed alternately. The control unit has a signal input terminal of the sub-torque sensor, a receiving terminal from the communication device, and a transmitting terminal to the communication device. The signal lines of the books send them without affecting each other.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment shown in FIGS. 1 and 2 is a power steering control device arranged across an engine room A and a vehicle interior B, and includes a main torque sensor 3, a sub torque sensor 4 and an electric motor 11. , Battery 12, controller 1
It is composed of FIG. 1 is a layout diagram of a power steering control device in a vehicle, and FIG. 2 is a block diagram. The communication device 5 outside the vehicle is connected. The control unit 1 includes a microcomputer 2, a power supply circuit 9, and a drive circuit 1.
The microcomputer 2 has a main torque signal input terminal 24 of the main torque sensor 3, a sub-torque signal input terminal 25, a transmission terminal 26 for the external transmitter 5, and a reception terminal 27. The main torque sensor 3 is connected to the control unit 1 via a signal line 13 and a connector 20.
The sub torque sensor 4 is connected to the control unit 1 via a signal line 14 and a connector 8. The communication device 5 is connected to the signal line 14 via the signal line 14 a and the connector 7. The signal line 14 branches at a branch point 21 and is connected to the signal line 14 a via the connector 7. Further, in the communication device 5, the signal line 14 a is branched to the signal line 14 b at the branch point 22. Further, a series resistor 17 is provided and installed between the branch point 21 and the sub torque sensor 4.

For the steering power assist, a current corresponding to a signal from the main torque sensor 3 is supplied from the battery 12 to the electric motor 11, and
The operation of the sub torque sensor 4 is similar to that of the conventional example. The communication device 5 for monitoring the control unit 1 is an external device, and is connected by the connector 7 when necessary. The microcomputer 6 in the communication device 5 has a transmission terminal 28 and a reception terminal 29, and transmission / reception is performed alternately. Since the same signal line 14 is used for reading the sub-torque sensor 4 and transmitting / receiving from the transmitting device 5, the three signals are performed at different times so as not to affect each other (time division method). . Regarding this point, the time charts of FIGS.
This will be described with reference to the flowchart of FIG. The voltage monitoring cycle of the sub torque sensor 4 does not need to be as fast as the torque detection cycle of the main torque sensor 3 that directly affects the steering feeling, and may be several tens ms to several hundred ms. Although the voltage monitoring time for one time is determined by the performance of the microcomputer, it is usually 0.1 ms or less.

In this embodiment, the reading cycle of the sub-torque sensor 4 is 100 ms, and the reading time required for one reading is 0.1 ms (FIG. 3 (a)). Then, after a sufficient time of 5 ms from the start of reading the sub-torque sensor 4 (steps 2 and 3), from the transmission terminal 26 of the control unit 1,
The necessary information is output within 40 ms by a pulse train (FIG. 3 (b), step 5). In step 13, the microcomputer 6 of the communication device 5 receives the data from the reception terminal 29 (FIG. 3 (c)). After that, a pause of 5 ms is provided, and this time, the communication device 5 transmits to the control unit 1 (steps 13 to 15). The controller 1 receives the data at the receiving terminal 27 (step 8). After that, there is a pause, and the control unit 1 repeats from step 2, and the communication device 5 repeats from step 11.

The transmission terminal 26 of the microcomputer 2 in the control unit 1 and the transmission terminal 28 of the microcomputer 6 in the communication device 5
The output state is in transmission mode and high impedance mode,
It has a structure that can be switched by software. Therefore, the transmission terminals 26 and 28 of the respective microcomputers 2 and 6 can be set to the high impedance mode except the transmission time. When transmitting from the communication device 5 to the control unit 1, the transmission terminal 26 of the microcomputer 2 is set to the high impedance mode and the transmission terminal 28 of the microcomputer 6 is set to the transmission mode in steps 6 and 15 of FIG. Since the same state as when the transmission terminal 26 of the microcomputer 2 is disconnected, the microcomputer 6
A precise signal can be received without affecting the transmission signal from the sub torque sensor 4 or the voltage of the sub torque sensor 4. The same applies when transmitting from the control unit 1 to the communication device 5. Further, by connecting the series resistor 17 to the sub torque sensor 4,
The sub torque sensor 4 which does not use the microcomputer performs the same operation as in the high impedance mode without switching the output mode and does not affect other signals.

The second embodiment shown in FIG. 5 is the same as the first embodiment except that the controller 1 and the electric motor 11 are integrated and arranged. In this way, in the case where the control unit 1 and the electric motor 11 are integrated, the control unit 1
The connection line between the electric motor 11 and the electric motor 11 can be shortened. As described above, in the conventional example, the three signal lines output from the control unit 1 are
The present invention reduced the number to one.

[0011]

According to the present invention, the signal line for the sub-torque signal, the transmission signal line for the external communication device, and the reception signal line can be shared, and the number of the signal lines from the control unit and the number of connectors can be reduced. . As a result, the parts and the manufacturing cost could be reduced.

[Brief description of drawings]

FIG. 1 is a layout diagram of a first embodiment.

FIG. 2 is a block diagram of the first embodiment.

FIG. 3 is a time chart of the first embodiment, in which (a) is a reading timing of the sub torque sensor, (b) is a transmission timing of the control unit, (c) is a reception timing of the communication device, and (d) is communication. The transmission timing of the device, (e) is the reception timing of the control device.

FIG. 4 is a flowchart of the first embodiment.

FIG. 5 is a layout view of a second embodiment.

FIG. 6 is a block diagram of a conventional example.

[Explanation of symbols]

 1 Control Part 3 Main Torque Sensor 4 Sub Torque Sensor 5 Communication Device 7 Connector 11 Electric Motor 14 Signal Line 14a Signal Line 14b Signal Line 21 Branch Point 22 Branch Point 28 Transmission Terminal 29 Reception Terminal

Claims (1)

[Claims] 1. An electric motor for power assisting steering, a main torque sensor for detecting steering torque of the steering, a sub torque sensor for outputting a voltage in cooperation with the main torque sensor, and a signal for the main torque sensor. In addition to supplying the corresponding current value to the motor, the main torque sensor is monitored for abnormalities by the relationship between the sub torque sensor and the main torque sensor, and the operating status information of the control device is communicated with an external communication device if necessary. In an electric power steering control device including a control unit having a function to perform, a branch is provided in a signal line connecting the sub torque sensor and the control unit, a connector is provided at a branch destination, and a signal line connected to the connector is provided. Further branch and connect each to the transmission terminal and the reception terminal of the external communication device, An electric power steering control device, characterized in that a reading of a sensor and a transmission / reception of a communication device are performed with a time difference.