JP2019203693A - Electronic control device - Google Patents

Abstract

To provide an electronic control device that can detect disconnection to the GND terminal.SOLUTION: Provided are: a power terminal 21 and a ground terminal 23 to which external power is connected; a power generation circuit 3 that generates an internal power supply for an electronic control device; a switching element provided between the power supply line connected to the power supply terminal and the other end of a solenoid 11; a semiconductor element connected between a ground line connected to the ground terminal and the other end of the solenoid to circulate the current flowing through the solenoid; an arithmetic control unit 5 that operates from the internal power source generated by the power source generation circuit and controls each of the switching elements to control the current flowing through the plurality of solenoids; and a pulse generation circuit that provides a pulse signal connected between the power supply line connected to the power supply terminal and the ground. A pulse train given by the pulse generation circuit is waveform-shaped, and it is determined that the ground terminal is not connected when the pulse train is a continuous signal after waveform shaping.SELECTED DRAWING: Figure 1

Description

  The present invention mainly relates to an electronic control device for controlling an engine and an automatic transmission, and more particularly to an electronic control device mounted on an automobile, a marine machine, an agricultural machine, and a construction machine.

  In recent years, with the intensification of competition for cost reduction, reduction and consolidation of automobile parts are frequently performed. Similarly, components for automatic transmissions have been reduced. As described in Patent Document 1, a configuration in which a harness on the downstream side of the solenoid is reduced is known.

  More specifically, the electronic control device disclosed in Patent Document 1 is “an electronic control device that controls a plurality of solenoids that are used for shift control of a vehicle transmission and that has one end connected to a vehicle body ground. A power supply terminal to which an external power supply is connected, a ground terminal, a power generation circuit that starts an operation when a voltage of the external power supply is applied, and generates an internal power supply of the electronic control device; A switching element provided between each of the solenoids, a switching line provided between a power line connected to the power supply terminal and the other end of the solenoid, and each of the plurality of solenoids; Connected between the ground line connected to the ground terminal and the other end of the solenoid, the current flowing through the solenoid is circulated. A first control unit that operates with an internal power source generated by the power source generation circuit and controls each of the switching elements to control a current flowing through the plurality of solenoids; and the power source generation circuit All the switching elements provided in each of the plurality of solenoids are simultaneously turned on before the control by the first control unit when the electronic control device is activated. An electronic control device comprising: a second control unit, wherein the operation of the power generation circuit is stopped when the second control unit is controlled when the ground terminal is in a disconnected state. It is comprised as follows.

Japanese Patent No. 576536

  However, according to the configuration described in Patent Document 1 in which the harness on the downstream side of the solenoid is reduced, the ground terminal (hereinafter referred to as GND terminal) of the electronic control device is disconnected, and at least one of the solenoid drive circuits includes at least one drive circuit. When the operation is stopped, a pseudo GND path is formed with the circuit GND-diode-current detection resistor-solenoid-vehicle body GND-battery GND, and the electronic control device even if the GND terminal of the electronic control device is disconnected. Will work.

  Since the pseudo GND path is via a diode, resistor, and solenoid, the impedance is large and the operation of the electronic control device becomes unstable, so the electronic control device operates when the GND terminal of the electronic control device is disconnected. It is not preferable to do so.

  In view of the above, an object of the present invention is to provide an electronic control device that can detect disconnection of the GND terminal when the harness on the downstream side of the solenoid is reduced.

  From the above, in the present invention, “an electronic control device that controls a plurality of solenoids each having one end connected to the ground, the power supply terminal to which an external power supply is connected, the ground terminal, and the voltage of the external power supply A power generation circuit that starts operation when applied and generates an internal power supply of the electronic control device, a power supply line provided to each of a plurality of solenoids, connected to a power supply terminal, and the other end of the solenoid; The switching element provided between each of the plurality of solenoids is provided for each of the plurality of solenoids, and is connected between the ground line connected to the ground terminal and the other end of the solenoid to return the current flowing through the solenoid. The semiconductor element for operation and the internal power generated by the power generation circuit operate to control each of the switching elements into a plurality of solenoids. An arithmetic control unit that controls the current generated, a pulse generation circuit that is connected between the power supply line connected to the power supply terminal and the ground and that provides a pulse signal, and a pulse train provided by the pulse generation circuit is waveform-shaped, and the pulse train is generated after waveform shaping The electronic control device includes a disconnection detection unit that determines that the ground terminal is in a non-connected state when it is a continuous signal and stops the operation of the notification, display, or calculation control unit.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic controller which makes it possible to detect the disconnection of the GND terminal when the harness on the downstream side of the solenoid is reduced can be obtained.

The figure explaining the Example of the electronic control apparatus which concerns on this invention. The figure which shows the waveform and electric potential of each part of the electronic control apparatus 2 in the normal time and a harness disconnection failure state. The flowchart which shows the processing content in the control calculating part 5 in the microcomputer 4, or the disconnection detection part 7. FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram for explaining an embodiment of an electronic control device according to the present invention. 1 includes a power generation circuit 3, a microcomputer 4, a plurality of solenoid drive circuits 10 (two sets of 10a and 10b are shown in FIG. 1), and a rotation detection unit 20 as main internal circuits. . The number of mounted solenoid drive circuits 10 varies depending on the transmission system, but there are always a plurality. Although two solenoid drive circuits are provided in FIG. 1, the present invention can be similarly applied to a case where three or more systems are provided.

  Among these, the power generation circuit 3 generates the power in the electronic control device 2 by the electric power supplied from the battery 1 outside the electronic control device 2. The electronic control device 2 is provided with a power supply terminal 21 and a GND terminal 23. The power supply terminal 21 is connected to a positive potential terminal of the external battery 1 and constitutes a positive potential bus 98 in the electronic control device 2. . The GND terminal 23 is connected to the negative potential terminal of the external battery 1 externally grounded at the ground point GND1, and constitutes a negative potential bus 99 in the electronic control unit 2. These power buses 98 and 99 serve as power sources for driving external devices (the solenoid 11 and the rotation sensor 12 in the example of FIG. 1) installed outside the electronic control unit 2.

  The power supply generation circuit 3 generates a control power supply that is power to be supplied to the microcomputer 4 as the power supply in the electronic control apparatus 2 using the power supplied from the battery 1 outside the electronic control apparatus 2. In FIG. 1, the control power supply for the microcomputer 4 is not shown.

  The plurality of solenoid drive circuits 10 are constituted by FETs, current detection resistors 8, operational amplifiers 9 and diodes D, and drive solenoids 11 outside the electronic control device 2. In the circuit configuration of FIG. 1, a series circuit of an FET and a diode D is connected between the positive potential bus 98 and the negative potential bus 99, and a current detection resistor is connected between the connection point of the FET and the diode D and the external ground point GND3. A solenoid 11 is connected in series via 8. The connection with the solenoid 11 outside the electronic control device 2 is performed via the connection terminal 22.

  The rotation detector 20 detects the primary, secondary, or clutch rotation speed of the automatic transmission, and is connected in series between the positive potential bus 98 and the external grounding point GND2 via the resistor 11 and the connection terminal 24. For example, a hall type rotation sensor 12 is provided.

  The microcomputer 4 inputs the solenoid current flowing through the current detection resistor 8 as a voltage signal Sg2 through the operational amplifier 9, and also inputs the pulse signal Sg1 of the number of rotations detected by the rotation sensor 12. The microcomputer 4 controls the ON / OFF of the FET according to the solenoid current, and can detect the disconnection of the GND terminal when the harness on the downstream side of the solenoid is reduced by using the rotation speed pulse signal Sg1.

  Hereinafter, the operation of the electronic control device 2 will be described in detail. First, the electronic control unit 2 operates with the battery 1 as a power source, and mainly controls the current flowing through the solenoid 11 that is responsible for the transmission shift control. In the solenoid drive circuit 10 of the solenoid 11, the FET functions as a switch for turning on and off the current flowing through the solenoid 11. The source of the FET is connected to a power supply line 98 (positive potential bus 98) to which the voltage of the battery 1 is applied, and the drain of the FET is connected to one end of a solenoid 11 that is a load via a current detection resistor 8. The other end of the solenoid 11 is connected to an external ground point GND3 which is a vehicle body ground terminal. In FIG. 1, external grounding points GND1 and GND2 are also vehicle body ground terminals.

  The diode D is a free-wheeling diode for returning the current flowing through the solenoid 11 when the FET is switched off. The anode of the diode D is connected to the ground line 99 (negative potential bus 99), and the cathode is connected to one end of the solenoid 11 via the current detection resistor 8. The current i flowing through the solenoid 11 is detected as a voltage signal Sg2 by the current detection resistor 8. The voltage signal Sg2 obtained by the current detection resistor 8 is amplified by the operational amplifier 9 and input to the microcomputer 4.

  The current i flowing through the solenoid 11 is controlled by switching the FET based on the calculation result of the control calculation unit 5 provided in the microcomputer 4. The control calculation unit 5 calculates the target current of the solenoid 11 and performs feedback control based on the target current and the detected current i so that the current i flowing through the solenoid 11 becomes the target current. By changing the duty of the PWM control signal for controlling the FET, the current flowing through the solenoid 11 can be changed. The solenoid drive circuit 10 related to the plurality of solenoids 11 also has the same configuration and function as the solenoid drive circuit 10 of the solenoid 11.

  In FIG. 1, a pulse signal Sg <b> 1 indicating the number of rotations from the rotation detection unit 20 is input to the disconnection detection unit 7 in the microcomputer 4. In the disconnection detection unit 7, for example, a pulse waveform shaping process is executed in order to convert a pulse signal having a magnitude detected by a hall-type rotation sensor 12 into a pulse signal having a magnitude handled in the microcomputer. In the pulse waveform shaping process, the input pulse is compared with the high and low two threshold values VH and VL, so that the pulse waveform of a new magnitude is “1” when larger than the threshold value VH, and smaller than the threshold value VL. A pulse signal of “0” is given.

  The electronic control device 2 configured as shown in FIG. 1 and having a reduced harness on the downstream side of the solenoid is configured as described above, for example, and one end of the solenoid 11 connected to the FET via the current detection resistor 8. Is connected to an external ground point GND3 which is a vehicle body ground.

  The electronic control device 2 includes connection terminals 21, 23, 22, and 24 for connecting an external device (battery 1, rotation sensor 12, solenoid 11) whose one end is grounded to the housing. A drive power supply by the positive potential bus 98 and the negative potential bus 99 and a control power supply for the microcomputer 4 are configured. A so-called harness is formed between the connection terminals 21, 23, 22, and 24 of the electronic control device 2 and the external device.

  In this configuration, when the feedback current i0 flowing through the solenoid 11 is examined when the FET is switched off, the feedback current i0 is the external grounding point GND1-GND terminal 23 of the external battery 1—the ground line 99 (negative potential bus 99). It circulates through the path of diode D, current detection resistor 8, connection terminal 22, solenoid 11 and external ground point GND3.

  On the other hand, in the configuration shown in FIG. 1, the GND connection line of the GND terminal 23 of the electronic control device 2 is disconnected or disconnected, and at least one of the plurality of solenoid drive circuits 10 is stopped. In this state, GND terminal 23-ground line 99 (negative potential bus 99) -diode D-current detection resistor 8-solenoid 11-external grounding point GND3 that is vehicle body ground-external grounding point GND1 that is vehicle body ground; A pseudo GND path is formed. Therefore, even if the GND terminal 23 of the electronic control device 2 is in a disconnected state, the electronic control device 2 can operate with reference to the vehicle body external grounding point GND3.

  However, when the GND terminal 23 is in a disconnected state as described above, it is desirable that the electronic control device 2 does not operate and the transmission stops functioning. Therefore, in the present invention, by adopting the control described below, the operation when the GND is not connected is detected to improve the reliability of the electronic control unit 2.

  FIG. 2 shows the waveforms and potentials of each part of the electronic control unit 2 in the normal state and in the harness disconnection state (the GND connection line of the GND terminal 23 is disconnected or disconnected). In FIG. 2, the horizontal axis represents time, and the vertical axis represents the waveform and potential of each part in the electronic control unit 2.

  In the uppermost stage of the vertical axis in FIG. 2, a) time history of normal and harness disconnection states is shown. Here, although it is a normal state until the time t0, it has shown that it was in the harness disconnection state (The GND connection line of the GND terminal 23 disconnected or the disconnection state) in the time t0.

  The second stage of FIG. 2 shows b) linear solenoid 11 waveform (point A). The waveform of b) is a rectangular wave signal reflecting the FET on / off control by the control calculation unit 5 in the microcomputer 4, and the circuit conditions are different before and after the harness disconnection at time t0. Are displayed as different.

  In the third row of FIG. 2, c) the potential at the ground line 99 (negative potential bus 99), and hence the GND terminal 23, is shown with reference to the external ground point GND1, which is the vehicle body ground. In a normal state before time t0, this potential is the external grounding point GND1, which is the vehicle body ground, and is 0 (V).

  In contrast, in the harness disconnection state (the GND connection line of the GND terminal 23 is disconnected or disconnected), when the FET is switched off, the feedback current i0 flowing through the solenoid 11 is simulated as described above. Since the current flows on the formed GND path, the potential at the ground line 99 (negative potential bus 99) and therefore the GND terminal 23 is, for example, about −5 (V) when the external ground point GND1 that is the vehicle body ground is used as a reference. And the potential VX fluctuates.

  The fourth stage of FIG. 2 shows the input waveform Sg1 from the rotation sensor 12 with reference to the ground line 99 (negative potential bus 99), and hence the GND terminal 23. Here, the dotted line indicates 0 (V), which indicates that the input waveform Sg1 from the rotation sensor 12 is compared with the high and low threshold values VH and VL.

  According to the waveform shaping process in the normal state in the disconnection detection unit 7, the input waveform Sg1 from the rotation sensor 12 is compared with the high and low threshold values VH and VL, so that a pulse waveform having a new size is obtained. The pulse train is “1” when it is larger than the threshold value VH and “0” when it is smaller than the threshold value VL.

  However, in the harness disconnection state after time t0 (the GND connection line of the GND terminal 23 is disconnected or disconnected), the potential fluctuation VX at the ground line 99 (negative potential bus 99), and hence the GND terminal 23, is detected by the rotation sensor 12. Is input to the disconnection detector 7 as a waveform biased to the input waveform Sg1.

  Since the biased waveform is sufficiently larger than the high level threshold value VH, the continuous pulse train obtained so far becomes a continuous high level signal, and this state continues. Thereby, the disconnection detection part 7 will detect rotation speed zero, and can be judged as a harness disconnection state, as shown to the 5th step | paragraph e) microcomputer rotation speed reading of FIG. In determining the harness disconnection state, it is possible to make a more accurate determination by adding other conditions (for example, solenoid current control is soundly executed) as an AND condition.

  In addition, it is as follows when the phenomenon in the harness disconnection state in FIG. When the return current when the linear solenoid 11 is turned off is pulled from the ground line 99 (negative potential bus 99), and hence from the GND terminal 23, the waveform of the ground line 99 in the electronic control device 2 sinks to the mass potential. For this reason, the rotation sensor input waveform on the basis of the ground line 99 in the electronic control unit 2 is floated by the sinking and becomes higher than the high level threshold value VH of the microcomputer 4. At this time, since the rotation speed reading value of the microcomputer 4 cannot recognize the pulse, it indicates zero rotation, and it is possible to detect the microcomputer zero rotation and detect the GND harness disconnection failure of the electronic control device.

  In the above processing according to the present invention, one end of the rotation sensor 12 is grounded, and the rotation sensor 12 is grounded with respect to the ground line 99 (negative potential bus 99) in the electronic control unit, and therefore the GND terminal 23. It is assumed that it is another ground.

  FIG. 3 is a flowchart showing the processing contents in the control calculation unit 5 or the disconnection detection unit 7 in the microcomputer 4.

  A series of processing flow after the controller activation in FIG. 3 is activated and executed at a constant control cycle in the microcomputer 4. In the processing of the microcomputer, first, the controller is activated in processing step S1, and as a data input necessary for calculation in the control calculation unit 5, for example, a voltage signal Sg2 corresponding to solenoid current, or a pulse signal of the number of rotations detected by the rotation sensor 12 Sg1 is input inside. Moreover, solenoid current control by the control calculation part 5 is performed in process step S2.

  In the processing step S3, as the processing of the disconnection detection unit 7, the waveform shaping processing is executed for the pulse signal Sg1 of the rotational speed detected by the input rotation sensor 12, and the result is a continuous pulse train or continuous. Whether the signal is a high level signal (or a continuous low level signal) is determined as normal or abnormal.

  If it is normal, the processing after processing step S2 is repeatedly executed in processing step S4. If it is the above, abnormality is reported and displayed in processing step S5, and the controller is stopped.

  According to the present invention described above, as a pulse generation source input by the electronic control unit 2, attention is paid to the rotation sensor 12 in the transmission, for example, and the waveform shaping process executed inside the electronic control unit 2 performs normal operation. Harness disconnection can be detected by utilizing the fact that the pulse train becomes a continuous signal when the harness is disconnected. Therefore, if there is an external device that generates pulses in addition to the rotation sensor 12, a substitution is possible.

1: battery 2: electronic control unit 3: power generation circuit 4: microcomputer 5: control calculation unit 7: disconnection detection unit 8: current detection resistor 9: operational amplifier 10: solenoid drive circuit 11: solenoid 12: rotation sensor 20: rotation detection Unit 21: Power supply terminal 22: Connection terminal 23: GND terminal 24: Connection terminal 98: Positive potential bus 99: Negative potential bus D: Diodes GND1, GND2, GND3: Ground point Sg2: Voltage signal Sg1: Pulse signal of rotation speed

Claims (3)

An electronic control device for controlling a plurality of solenoids each having one end connected to a ground,
A power supply terminal to which an external power supply is connected, a ground terminal, a power supply generation circuit that starts operation when a voltage of the external power supply is applied, and generates an internal power supply of the electronic control device, and each of the plurality of solenoids A switching element provided between a power supply line connected to the power supply terminal and the other end of the solenoid, and a switching element provided for each of the plurality of solenoids. It is connected between the connected ground line and the other end of the solenoid, and operates by a semiconductor element for returning a current flowing through the solenoid, and an internal power source generated by the power generation circuit, and the switching An arithmetic control unit that controls each of the elements to control currents flowing through the plurality of solenoids, and a power supply line connected to the power supply terminal A pulse generation circuit connected between the grounds for supplying a pulse signal and a pulse train provided by the pulse generation circuit are waveform-shaped, and it is determined that the ground terminal is in a disconnected state when the pulse train is a continuous signal after waveform shaping. An electronic control device comprising a disconnection detection unit that stops notification, display, or operation of the arithmetic control unit. The electronic control device according to claim 1, which is used for shift control of a vehicle transmission,
The electronic control device according to claim 1, wherein the pulse generation circuit is a rotation sensor that detects the number of rotations of the primary, secondary, or clutch of the vehicle transmission. An electronic control device according to claim 1 or claim 2,
The electronic control device according to claim 1, wherein a ground to which one end of the pulse generation circuit is connected is a ground different from the ground terminal.

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