JP3620356B2 - Vehicle control apparatus and engine control microcomputer used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle control device that temporarily disconnects a clutch during gear shifting of a transmission and controls the engine speed in accordance with the clutch operation, and an engine control microcomputer used therefor.
[0002]
[Prior art]
An automatic transmission having a transmission having a plurality of shift stages and capable of automatic transmission and configured to disconnect or connect the friction clutch by a microcomputer or the like in a vehicle configured to transmit engine output to the axle via the friction clutch and the transmission. A system has been proposed. The automatic transmission system includes a transmission ECU for controlling the engagement and disengagement of the friction clutch and a gear shift of the transmission, and an engine ECU for controlling the operating state of the engine, and both ECUs can communicate with each other. Connected in a state.
[0003]
When a gear shift is requested according to the vehicle running state or the driver's will, the transmission ECU performs the gear shift after disconnecting the friction clutch, and then instructs the engine ECU to control the rotational speed. Then, when the engine speed is controlled according to the instruction of the speed control, the friction clutch is connected. At this time, when the engine ECU receives an instruction for rotational speed control from the transmission ECU, the engine ECU temporarily controls the engine rotational speed to such an extent that the clutch can be reconnected.
[0004]
More specifically, regarding the rotational speed control, the state of clutch engagement or disengagement is determined on the transmission ECU side, and when it is determined that the clutch is disconnected, an instruction for rotational speed control is transmitted from the transmission ECU to the engine ECU. When the engine ECU receives an instruction for rotational speed control from the transmission ECU, the engine ECU enters a rotational speed instruction mode and performs engine control so that the engine rotational speed is matched with the instructed rotational speed.
[0005]
[Problems to be solved by the invention]
However, in the above prior art, only the transmission ECU determines the state of the clutch, and the engine ECU performs the rotational speed control only in accordance with the instruction from the transmission ECU by communication. If an instruction for rotational speed control is erroneously transmitted to the engine ECU, there is an inconvenience that the rotational speed control is inadvertently performed. In this case, in the state of clutch connection, that is, the drive line (drive system) from the engine to the axle is connected, the rotational speed control is performed regardless of whether or not the actual gear shift is necessary. On the other hand, the engine speed changes and drivability deteriorates.
[0006]
The present invention has been made paying attention to the above problems, and the object of the present invention is to provide a vehicle control device capable of suppressing unintentional rotation speed control and realizing good vehicle travel. It is to provide an engine control microcomputer used therefor.
[0007]
[Means for Solving the Problems]
In the vehicle control device according to claim 1, the first microcomputer for engine control and the second microcomputer for shift control are connected to be communicable with each other, and the first microcomputer is connected to the second microcomputer. When the clutch is temporarily disconnected by the computer, the engine speed is controlled to a speed at which the clutch can be reconnected. Further, in particular, when the first microcomputer inputs both the rotation speed control start instruction transmitted from the second microcomputer after completion of the clutch disengagement and the clutch disengagement signal from the clutch detection means, the clutch actually It is determined that the engine has been disconnected, and execution of engine speed control for clutch reconnection is permitted. As a result, in addition to avoiding the inconvenience of inadvertently performing the rotational speed control regardless of the gear shift due to a communication abnormality or the like, the rotational speed is erroneously requested even if the rotational speed control is erroneously requested. Control is not carried out improperly . As a result, good vehicle travel can be realized.
[0009]
3. The engine control microcomputer according to claim 2 , wherein an instruction for starting the rotation speed control transmitted from another microcomputer for shift control and a clutch disconnection from a clutch detection means for detecting a clutch disengagement or engagement state. When the signal is input together, the engine speed control for clutch reconnection is permitted. In such a case, as in claim 1, in addition to avoiding the inconvenience that the rotational speed control is inadvertently performed regardless of the gear shift due to a communication abnormality or the like, the rotational speed control is erroneously requested. Even if it is done, the rotational speed control will not be performed improperly . As a result, good vehicle travel can be realized.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the vehicle control system according to the present embodiment, an automobile equipped with a diesel engine and a transmission capable of automatic transmission is controlled, and the engine output is transmitted to the transmission side via a clutch. Further, in the vehicle control system, an engine ECU as a first microcomputer that controls the operating state of the diesel engine, and clutch disengagement and connection are controlled according to the vehicle running state and the transmission gear shift is performed. And a transmission ECU as a second microcomputer. Then, these two ECUs appropriately perform gear shift and associated engine control while the vehicle is traveling, while exchanging information with each other by communication. The configuration and operation will be described in detail below.
[0012]
FIG. 1 is an overall configuration diagram showing an outline of the vehicle control system. In FIG. 1, an engine 10 is a multi-cylinder diesel engine, and fuel supplied from a fuel injection device 11 is supplied to each cylinder by injection. The fuel injection device 11 is, for example, a common rail type fuel injection device, and fuel stored in a high pressure state on a common rail (pressure accumulation pipe) (not shown) is injected into each cylinder as the electromagnetic injector is driven. It is used for combustion in the cylinder. The rotational speed of the engine 10 is detected by, for example, an engine rotational speed sensor 12 disposed on a crankshaft (not shown).
[0013]
A transmission 14 having a plurality of shift stages is connected to the engine 10 via an air pressure control type friction clutch 13. The friction clutch 13 includes a flywheel 15 connected to the output shaft 10 a of the engine 10 and a clutch plate 16 facing the flywheel 15. The clutch plate 16 is pressed against the flywheel 15 as the clutch actuator 17 is driven. It is controlled to the position of separation. That is, when the clutch actuator 17 shifts from the non-operating state to the operating state, the clutch plate 16 is pressed against the flywheel 15 and the friction clutch 13 changes from the disconnected state to the connected state. Further, when the clutch actuator 17 shifts from the operating state to the non-operating state, the clutch plate 16 is separated from the flywheel 15 and the friction clutch 13 is changed from the connected state to the disconnected state.
[0014]
Although illustration of the detailed structure of the clutch actuator 17 is abbreviate | omitted, it has the following structures in general. That is, the clutch actuator 17 has, as main components, an electromagnetic on-off valve that connects and disconnects an air passage 19 between the air tank 18 and an air cylinder that operates by air pressure supplied through the electromagnetic on-off valve. When the clutch pedal is operated by the driver, the friction clutch 13 is disconnected. Further, the clutch actuator 17 temporarily disengages the friction clutch 13 in accordance with a control signal from a transmission ECU 40 (described later) at the time of gear shifting while the vehicle is running.
[0015]
Here, the friction clutch 13 is disposed on the clutch touch sensor 20 for detecting the disengagement or connection state of the clutch 13 and the input shaft 14a of the transmission 14, and on the clutch plate 16 side (input shaft 14a). A clutch rotational speed sensor 21 for detecting the rotational speed is attached. In the present embodiment, the clutch touch sensor 20 corresponds to the clutch detection means.
[0016]
A gear shift actuator 22 that operates according to a control signal from the transmission ECU 40 at the time of gear shift is attached to the transmission 14. The gear shift actuator 22 drives a power cylinder (not shown) by the high-pressure operating air from the air tank 18, and thereby the gear position is switched to the target shift stage. A gear position sensor 23 for detecting the gear position is attached to the transmission 14, and a vehicle speed sensor 24 for detecting the vehicle speed is attached to an output shaft (axle) (not shown) of the transmission 14.
[0017]
Each of the engine ECU 30 and the transmission ECU 40 includes a well-known logic operation circuit including a CPU, a ROM, a RAM, an input / output circuit, and the like, and both the ECUs 30 and 40 are connected so as to communicate with each other. The engine ECU 30 receives detection signals from the engine speed sensor 12, the clutch touch sensor 20, and the vehicle speed sensor 24 described above, and in addition, a detection signal of an accelerator pedal depression operation amount by the accelerator pedal sensor 25. Entered. The engine ECU 30 adjusts the output torque and the number of revolutions of the engine 10 by controlling the fuel injection amount by the fuel injection device 11 at the time of gear shift of the transmission 14 based on the detection signals of these inputted sensors.
[0018]
The transmission ECU 40 receives detection signals from the clutch touch sensor 20, the clutch rotational speed sensor 21, and the gear position sensor 23 described above, and, in addition, a gear selection signal (shift) by the shift lever 26. Signal) and a detection signal of the operation state of the clutch pedal by the clutch pedal sensor 27 are input. The transmission ECU 40 operates the clutch actuator 17 to disconnect and connect the friction clutch 13 and operates the gear shift actuator 22 based on the input detection signals of the sensors to shift the gear. I do.
[0019]
Incidentally, in the present embodiment, a shift range of the shift lever 26 is provided with a manual range in which the driver can manually switch the shift position and an automatic range in which the shift position is switched automatically. Stage up / down (shift up, shift down) can be operated manually. In the automatic range, the gear shift is performed by determining whether or not the gear shift is necessary according to the vehicle running state.
[0020]
Next, the operation at the time of gear shift performed by the engine ECU 30 and the transmission ECU 40 will be described with reference to the flowcharts of FIGS. 2 to 5 and the time chart of FIG. FIG. 6 shows how signals are exchanged between the ECUs 30 and 40, changes in engine speed, changes in engine output torque, the intermittent state of the friction clutch 13, and gear shift operations.
[0021]
FIG. 2 is a flowchart showing a main routine executed by the transmission ECU 40. In FIG. 2, when a gear shift request is generated in accordance with the vehicle running state (YES in step 100), the transmission ECU 40 determines torque reduction, rotational speed instruction, torque return. The three processing modes are sequentially executed (steps 110, 130, and 150). For example, when the shift lever is in the manual range and the driver manually shifts up or down, or the shift lever is in the automatic range, the gear shift can be performed depending on the gear position, accelerator pedal depression amount, vehicle speed, etc. When it is determined that it is necessary, step 100 is affirmed.
[0022]
When the above three processing modes are sequentially performed at the time of gear shifting, the transmission ECU 40 performs the processing of FIG. 3A, FIG. 4A, and FIG. In response to this, the engine ECU 30 performs the processes of FIG. 3B, FIG. 4B, and FIG. 5B, which will be described later, in accordance with an instruction transmitted from the transmission ECU 40. Hereinafter, the processing contents of the three modes will be described in detail.
[0023]
First, in the torque reduction mode, the transmission ECU 40 executes the process of FIG. That is, in step 111, a torque reduction command indicating that the engine output torque is to be reduced is transmitted to engine ECU 30. In steps 112 and 113, the mode state of the engine ECU 30 and the engine output torque are read based on the signal received from the engine ECU 30, and in the subsequent step 114, the torque reduction mode is completed from the read mode state and the engine output torque. It is determined whether or not. If the torque reduction mode is not completed, steps 111 to 114 are repeatedly executed, and if the torque reduction mode is completed, the process proceeds to step 115.
[0024]
In step 115, the clutch actuator 17 is operated to change the friction clutch 13 from the previous connected state to the disconnected state. In the following step 116, the gear shift actuator 22 is operated to control gear shift, and then this routine is terminated.
[0025]
On the other hand, the engine ECU 30 executes the process of FIG. 3B every 10 msec, for example. That is, in FIG. 3B, in step 211, it is determined whether a torque reduction command is received from the transmission ECU 40 or not. When a torque reduction command is received, the torque reduction mode is entered and torque reduction processing is performed (steps 212 and 213). In practice, the fuel injection amount by the fuel injection device 11 is decreased to decrease the engine output torque to a predetermined value (for example, 0). At this time, the output torque information is sequentially transmitted to the transmission ECU 40.
[0026]
In the time chart of FIG. 6, after time t1, a torque reduction command is transmitted from the transmission ECU 40 to the engine ECU 30 (A1 in the figure), and conversely, a signal indicating that the torque reduction mode has entered from the engine ECU 30 to the transmission ECU 40, and the engine output A signal indicating torque is transmitted (B1 in the figure). Thereafter, torque reduction processing is performed by the engine ECU 30, and when the engine output torque decreases to, for example, 0 at time t2, the transmission ECU 40 determines that the torque reduction mode is complete, and the friction clutch 13 is disconnected. After that minute time, gear shift is performed. However, FIG. 6 shows an example in which the gear speed is increased.
[0027]
Further, in the rotation speed instruction mode, the transmission ECU 40 executes the process of FIG. 4A, first, at step 131, a rotation speed instruction command is transmitted to the engine ECU 30. In step 132, the mode state of the engine ECU 30 is read based on the signal received from the engine ECU 30, and in the subsequent step 133, it is determined whether or not the engine ECU 30 has entered the rotational speed instruction mode from the read mode state. If the engine speed has not entered the engine speed instruction mode, steps 131 to 133 are repeatedly executed. If the engine has entered the engine speed instruction mode, the process proceeds to step 134.
[0028]
In step 134, the engine speed instruction command is transmitted to engine ECU 30 again. In step 135, the engine speed is read based on the signal received from engine ECU 30. In step 136, the clutch rotational speed is read based on the detection result of the clutch rotational speed sensor 21. Thereafter, in step 137, it is determined whether or not the engine speed matches the clutch speed and the friction clutch 13 can be reconnected. If the clutch connection is not possible, steps 134 to 137 are repeatedly executed, and if the clutch connection is possible, the process proceeds to step 138.
[0029]
In step 138, the clutch actuator 17 is operated to gradually connect the friction clutch 13. In steps 139 to 141, transmission of the rotation speed instruction command, reading of the engine rotation speed, and reading of the clutch rotation speed are performed again. Thereafter, in step 142, it is determined whether or not the connection of the friction clutch 13 is completed. If the clutch connection is not completed, steps 138 to 142 are repeatedly executed, and if the clutch connection is completed, this routine is terminated as it is.
[0030]
In contrast, the engine ECU 30 executes the process of FIG. That is, in FIG. 4B, in step 231, it is determined whether or not a rotation speed instruction command has been received from the transmission ECU 40. In step 232, the friction clutch 13 is actually operated based on the detection signal of the clutch touch sensor 20. It is determined whether or not it is disconnected. Then, only when both steps 231 and 232 are YES, the torque reduction mode is canceled at step 233, and at step 234, the engine enters the rotation speed instruction mode according to the rotation speed instruction command.
[0031]
Furthermore, in step 235, the rotational speed control is performed by adjusting the fuel injection amount by the fuel injection device 11. At this time, the engine speed information is sequentially transmitted to the transmission ECU 40. Thereafter, in step 236, it is determined whether or not the clutch connection in the transmission ECU 40 has been completed. If it is not completed, the rotational speed control is continued, and if it is completed, this routine is terminated.
[0032]
In the time chart of FIG. 6, after time t3, a transmission speed instruction command is transmitted from the transmission ECU 40 to the engine ECU 30 (A2 in the figure), and conversely, a signal indicating that the rotation speed instruction mode has entered from the engine ECU 30 to the transmission ECU 40; A signal indicating the engine speed is transmitted (B2 in the figure). At time t4, it is determined that the engine speed matches the clutch speed and the clutch can be reconnected, and the clutch connection is started by the transmission ECU 40. After time t4, both the output torque and the engine speed increase with clutch engagement. At time t5, it is determined that the clutch connection is completed.
[0033]
Further, in the torque return mode, the transmission ECU 40 executes the process of FIG. That is, first in step 151, a torque return command indicating that the engine output torque is to be returned is transmitted to the engine ECU 30. In steps 152 and 153, the mode state of the engine ECU 30 and the engine output torque are read based on the signal received from the engine ECU 30, and in the subsequent step 154, the torque return mode is completed from the read mode state and the engine output torque. It is determined whether or not. If the torque return mode is not completed, Steps 151 to 154 are repeatedly executed, and if the torque return mode is completed, this routine is terminated.
[0034]
In contrast, the engine ECU 30 executes the process of FIG. That is, in FIG. 5B, in step 251, it is determined whether or not a torque return command is received from the transmission ECU 40. When the torque return command is received, the rotational speed instruction mode is canceled at step 252 and the torque return mode is entered at step 253 according to the torque return command.
[0035]
Thereafter, in step 254, the amount of fuel injected by the fuel injection device 11 is controlled to perform torque return processing. In the subsequent step 255, it is determined whether or not the engine output torque has returned to the driver's required value. If step 255 is NO, the torque return process is continued. If step 255 is YES, the torque return mode is canceled at step 256, and then this routine is terminated.
[0036]
In the time chart of FIG. 6, after time t5, a torque return command is transmitted from the transmission ECU 40 to the engine ECU 30 (A3 in the figure), and conversely, a signal indicating that the torque return mode has been entered from the engine ECU 30 to the transmission ECU 40, and the engine output A signal indicating torque is transmitted (B3 in the figure). Then, the engine output torque is increased by the torque recovery process, and it is determined at time t6 that the torque recovery is complete.
[0037]
According to the embodiment described in detail above, the following effects can be obtained.
The engine ECU 30 determines that the friction clutch 13 is actually disconnected when both the rotational speed instruction command from the transmission ECU 40 and the clutch disconnection signal from the clutch touch sensor 20 are input, and enters the rotational speed instruction mode. Therefore, the rotational speed control is performed by double check of clutch disengagement. Therefore, the inconvenience that the rotational speed control is inadvertently performed regardless of the gear shift due to the abnormality on the transmission ECU 40 side or the communication abnormality between the ECUs 30 and 40 is avoided. For example, even if a rotational speed instruction command is erroneously transmitted from the transmission ECU 40 in the clutch connected state, the rotational speed instruction mode is not entered, and the rotational speed control contrary to the driver's will is performed improperly. There is no. As a result, drivability is improved and good vehicle travel can be realized, and safety during vehicle travel is further improved.
[0038]
In particular, the vehicle control system of the present embodiment can be suitably embodied in a vehicle such as a truck that has a large transmission torque from the engine to the drive system and is unsuitable for employing a fluid torque converter.
[0039]
In addition to the above, the present invention can be embodied in the following forms.
In the above-described embodiment, the fuel injection amount is controlled when the torque reduction, the rotation speed control, and the torque return process are performed at the time of gear shift. Instead, the accelerator opening may be controlled.
[0040]
In the above-described embodiment, the clutch actuator 17 and the gear shift actuator 22 are pneumatically controlled. However, other configurations may be adopted such as replacing this with hydraulic control. In addition to diesel engines, it can also be applied to gasoline engines.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an overview of a vehicle control system in an embodiment of the invention.
FIG. 2 is a flowchart showing a main routine of the transmission ECU.
FIG. 3 is a flowchart showing processing in a torque reduction mode.
FIG. 4 is a flowchart showing processing in a rotation speed instruction mode.
FIG. 5 is a flowchart showing processing in a torque return mode.
FIG. 6 is a time chart showing more specifically the operation during gear shifting.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Engine, 13 ... Friction clutch, 14 ... Transmission, 20 ... Clutch touch sensor as a clutch detection means, 30 ... Engine ECU (1st microcomputer, engine control microcomputer), 40 ... Transmission ECU (2nd Microcomputer).

Claims (2)

A clutch for transmitting engine output to the transmission;
A first microcomputer for controlling the operating state of the engine;
A second microcomputer for controlling the disengagement and connection of the clutch in accordance with the running state of the vehicle, and for performing gear shifting of the transmission;
Clutch detecting means for detecting the state of disconnection or connection of the clutch,
The first and second microcomputers are communicably connected to each other, and the first microcomputer can reconnect the engine speed when the clutch is temporarily disconnected by the second microcomputer. In the vehicle control device that controls the rotational speed,
The second microcomputer instructs the start of the rotational speed control after the clutch disengagement is completed,
The first microcomputer, instructions and the rotational speed control start to be transmitted from the second microcomputer, when you enter both a signal clutch disengagement by the clutch detecting means, engine rotational for clutch reconnection A vehicle control device that permits execution of number control. Used in vehicle control devices that temporarily disengage the clutch when shifting the gear of the transmission and control the engine speed for clutch engagement when the clutch is reconnected. An engine control microcomputer that is communicably connected to another microcomputer,
  When both the instruction to start the rotational speed control sent from the other microcomputer after the completion of the clutch disconnection and the clutch disconnection signal from the clutch detection means for detecting the clutch disconnection or engagement state are input, An engine control microcomputer for use in a vehicle control device, which permits execution of engine speed control for connection.

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