JP2001225667A - Failsafe device for constant speed travel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a failsafe device for a constant speed travel device surely canceling when there is some abnormality in the constant speed travel device or controlled stop and also holding the state. SOLUTION: The constant speed travel device comprising a command signal input means 2, a cancel signal input means 3, a motor type actuators with clutch 8, 10, a CPU 6, and a latch means 9 outputs a signal making the actuator 8 return to the initial position in inputting a cancel signal or detecting something abnormal by the CPU 6, actuates the latch means 9 to turn off the clutch 10, and holds the latch means 9 in its state unless executing a prescribed procedure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fail-safe device for a constant-speed traveling device having a motor-type actuator, which surely cancels the constant-speed traveling when an abnormality of the device or a cancel signal is input. It is.

[0002]

2. Description of the Related Art Conventionally, in order to reduce the driving burden on a vehicle, automatic acceleration, automatic deceleration,
Constant-speed traveling devices having three modes of vehicle speed holding have been developed. In particular, a negative pressure type actuator using an engine negative pressure has been frequently used as an actuator for controlling opening and closing of a throttle valve of an engine. A microcomputer (hereinafter referred to as a CPU) for driving the negative pressure type actuator controls a valve for introducing a negative pressure and a valve for introducing the atmosphere to open and close a throttle valve,
The vehicle is traveling at a desired constant speed. In addition, a function of detecting a malfunction of the actuator by comparing a control signal for driving each valve with a monitor signal for monitoring the valve state was also provided.

In a negative pressure type actuator, when a power supply voltage is low, a valve portion is configured so that the actuator operates in a deceleration mode. In other words, the valve drive current is reduced by the decrease in the power supply voltage, and is defeated by the spring force to act in the air introduction direction. However. If the motor-type actuator becomes uncontrollable due to a drop in power supply voltage, it may stop at that state. For this reason, a clutch mechanism is added so that the throttle valve cannot be opened unless the clutch is turned on. If a clutch stuck failure occurs, the vehicle may run away, and a fail-safe function is particularly important for a motor-type actuator.

As a conventional device, Japanese Patent Publication No. Hei 7-1127 is used.
There is an apparatus described in Japanese Patent Publication No. 86, and FIG. 9 shows a block configuration thereof. In FIG. 9, 1 is a speed signal generating means for detecting the running speed of the vehicle, 2 is a command signal input means for starting a constant speed running by an external operation, and 3 is a cancel for terminating the constant speed running by an external operation. Signal input means. Reference numeral 5 denotes an input circuit for processing the input signal, and reference numeral 16 denotes a control CPU for calculating various control amounts. Reference numeral 7 denotes an output circuit for processing according to the control signal of the CPU. Reference numeral 21 denotes a negative pressure introduction valve, and reference numeral 22 denotes an atmosphere introduction valve. Both valves 21 and 22 constitute a negative pressure type actuator. The switching elements 23 and 24 are
An actuator drive circuit that drives the valves 21 and 22 according to a control signal of the CPU is configured. Reference numeral 18 denotes a latch unit, which can be reset by the logical sum (17) of the CPU 16 or the cancel signal (3), and is provided with a command signal (2).
D-type flip-flop (hereinafter DFF)
). The output Q of the DFF 18 is a power supply circuit 2 for controlling the power supply of the actuators (21, 22).
Drive 0. That is, when the DFF 18 is in the set state, the power supply (14) can be supplied to the actuator.
If the FF is in the reset state, the power supply (14) is shut off. The state of the DFF output is monitored by the CPU.

[0005] In the conventional apparatus configured as described above, the CP
Latch means 18 composed of a DFF separately from U16
The power of the actuator is controlled by the operation of the latch. Power cutoff by latch is C
Since it operates independently of the PU, it works effectively when a CPU failure occurs. Further, once a cancel input is made, the DFF maintains the reset state unless a command is input next, so that the actuator does not operate in the direction in which the throttle valve is opened, thereby ensuring safety.

[0006]

However, if the actuator is not a negative pressure type but a motor type, simply turning off the power supply cannot always keep the constant speed traveling device in the same canceling state. That is, there has been a problem that a question arises in securing a reliable cancellation state.
In addition, if the operation is restored only by the command input signal after the cancellation, the operation may be restored by the driver's operation, and then the operation may be canceled again. Thus, there is a problem that the operation is repeatedly executed. In view of the above, an object of the present invention is to provide a device that ensures a secure fail-safe even for a constant-speed traveling device having a motor-type actuator.

[0007]

In the fail-safe device for a constant-speed traveling device according to the present invention, command signal input means for generating a command signal for instructing start of constant-speed traveling by external operation or external information, A motor type actuator having a cancel signal input means for generating a cancel signal for instructing the end of constant speed running by external operation or external information, and a clutch capable of controlling the output of the engine and connecting and disconnecting the engine output control A microcomputer which has an actuator driving means for controlling the actuator and an abnormality detecting function for detecting an abnormality of the constant-speed traveling device, and which outputs a control signal for controlling the actuator to perform a desired constant-speed traveling. When the abnormality is detected or the cancel signal is input, the actuator is initially Initialization signal generating means for outputting a signal for returning to a position, and latch means for operating the actuator driving means so as to hold the clutch in an off state unless a predetermined procedure for canceling is performed. Things.

In the fail-safe device for a constant-speed traveling device according to the present invention, when releasing the latch means, the latch can be released by executing a predetermined procedure based on a combination of a plurality of signals of a microcomputer. It is to become.

In the fail-safe device for a constant-speed traveling device according to the present invention, when the latch means is operated, it is set that at least one of an abnormality detection signal, a cancel signal, and an output signal from the microcomputer is input. The latch state is maintained thereafter.

Further, in the fail-safe device for a constant-speed traveling device according to the present invention, the display means for indicating the operating state of the constant-speed traveling device, the state detecting means for detecting the constant-speed traveling state, and the state detecting means are fixed. In response to the detection of the interruption or termination of the high-speed running, the display means is deactivated and the latch means is set.

Further, in the fail-safe device for a constant-speed traveling device according to the present invention, when the constant-speed traveling control is temporarily interrupted and the control is started again, the actuator is returned to the initial position and then the constant-speed traveling device is operated. And a microcomputer that operates to cause the

Further, in the fail-safe device for a constant-speed traveling device according to the present invention, a function of detecting an actuator abnormality by comparing an actuator driving control signal output from the microcomputer itself with a signal indicating an actuator operating state. And a microcomputer having the following.

Further, the fail-safe device for a constant-speed traveling device according to the present invention is provided with a stepping motor type actuator based on a four-phase control signal, and the microcomputer controls the four-phase control signal for mutually contradictory signals. Exclusive logic signals are input to each other, and an abnormality of the actuator is detected by comparing the four-phase control signal with the exclusive logic signal. When the abnormality is detected, the constant speed traveling is terminated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the entirety of a constant-speed traveling device according to Embodiment 1 of the present invention. In FIG. 1, 1 is a speed signal generating means for detecting a running speed of a vehicle, 2 is a command signal input means for starting a constant speed running by an external operation, and 3 is a cancel for terminating the constant speed running by an external operation. Signal input means. 5 is an input circuit for inputting the various information, 6 is C
PU and 7 are output circuits that respond to control signals from the CPU 6. Reference numeral 8 denotes a stepping motor having a four-phase coil. Reference numeral 10 denotes a clutch, which acts so as to connect and disconnect the rotational drive of the motor to the opening / closing operation of a throttle valve (not shown). The motor 8 and the clutch 10 constitute a motor type actuator. Numeral 9 denotes a clutch driving means for controlling the clutch 10 and comprises DFFs 9a and 9b and a transistor 9c. The driving means of the stepping motor is included in the output circuit 7 and is not shown in detail, but is constituted by a transistor group such as 7a. The actuator driving means is constituted by the motor driving means and the clutch driving means 9. Reference numeral 4 denotes an exclusive logic signal means for forming an exclusive logic signal 4a having a phase opposite to the A phase and an exclusive logic signal 4b having a phase B and the phase among the control signals for driving the stepping motor 8. Reference numeral 11 denotes a display unit that indicates that the vehicle is running at a constant speed. Reference numeral 13 denotes a control circuit for reset terminals of the DFFs 9a and 9b. Reference numeral 12 denotes power supply voltage detecting means for monitoring the power supply voltage, and 14 denotes a power supply.

The operation of the constant-speed traveling device having the above-described configuration will be described. The speed signal generating means 1 generates a frequency pulse train signal corresponding to the running speed of the vehicle, and the CPU 6 inputs the signal to calculate the running speed. Here, when the command signal (2) is generated by the operation of the driver, the constant-speed traveling is started unless the constant-speed traveling device is abnormal. The running speed at this point is stored, and thereafter the automatic speed control is performed at the stored speed. If the command signal is a resume signal, the constant speed traveling is automatically accelerated / decelerated to the storage speed before canceling to increase the traveling speed, and thereafter, the vehicle enters the constant speed traveling mode. In addition, it is a well-known traveling control that depends on a driver's acceleration command and deceleration command and can vary the control speed. Further, there is a device that performs automatic speed control depending on the distance between the vehicle and the vehicle ahead in addition to the operation of the driver. In this case, by superimposing the command signal on the command signal, the constant speed traveling can be similarly operated.

On the other hand, the cancellation signal (3)
The constant speed running is forcibly terminated by an operation of a driver such as a clutch, a turn signal, a horn or the like.
Are input to the reset terminals (R1, R2). CPU6
The actuators 8 and 10 are also deactivated by the latch means 9a and 9b together with the control signal. In addition to the cancellation by the driver's operation, the inter-vehicle distance information can be used as described above. Reference numeral 13 denotes a reset terminal control circuit whose circuit network is configured so that the DFFs 9a and 9b are in a reset state unless the display means 11 is in a constant speed running state. That is, when the transistor 11b is off (non-constant speed running state), the transistor 13b is turned on by the pull-up resistor 13a and the reset terminal R1,
R2 goes to the L state. Therefore, the output Q1 of the DFF 9b is L
And the transistor 9c is off, thus the clutch is inactive.

The motor drive is a four-phase coil type stepping motor, and the motor can be rotated forward and backward by sequentially driving each phase. Next, the operation of the latch means which is a main part of the clutch driving means 9 will be described. The CPU 6 controls the control signal 7b,
Release latch means 9a, 9b using 7c, 7d,
An H signal is output from the output Q1 of the DFF 9b, and the transistor 9c is driven thereby, thereby causing a current to flow through the clutch coil (10). Thus, when the motor is driven, the throttle valve can be opened and closed.

Referring to FIG. 2, latch means 9a, 9b
Will be described. 31 is a reset terminal R1,
R2 and 32 are D2 terminals of DFF 9a, 33 is CK2 terminal, 34 is 2 terminals, 35 is D1 terminal of DFF 9b, 36
Shows the state of the Q1 terminal. First, a case where the clutch is turned on will be described. When a command is input at time t1 and the CPU 6 detects no abnormality, the CPU 6 outputs a control signal for turning on the display unit 11, and the reset terminal of the DFF releases the reset state (switched from L level to H level). . However, even if the reset state is released, the set state is not immediately established, and the reset state is maintained.

To set the latch to the set state, first, t2
Output the 7c control signal 32 as H. Next, at t3, the 7d control signal 33 is set to H, and thereafter, H / L is periodically repeated.
Then, 2 (34) switches from H to L level. t4
Output the 7b control signal 35 as H. Further, the 7c control signal 32 is switched to the L output. 7b control signal 35 is also H
Output. When the 7d control signal switches to H at t5, 2 (34) also rises from L to H. Only at the rise of 2 does Q1 become H and the clutch is turned on (36). Thus, the clutch can be turned on by a combination of a plurality of control signals from the CPU.
As a result, after the cancel signal disappears, the clutch cannot be turned on only by inputting noise or a command signal, thereby improving safety. Further, since the latch function can maintain the reset state of the constant speed traveling, safety is further ensured.

Conversely, the case where the constant speed running state is ended will be described. It is assumed that there is a cancel input at t6. Then, the DFF operates to pull the R1 and R2 terminals directly to the L level. Therefore, the DFFs 9a and 9b both enter the reset state, and the clutch drive transistor 9c is turned off. Also, if the CPU detects an abnormality at t6, it outputs a signal to turn off the transistor 11b, so that the transistor 13b is turned on and the DFF R1, R2
Becomes L and enters a reset state. Therefore, the clutch is immediately turned off (36 solid line). Furthermore, when there is no cancel input or abnormality, the constant speed traveling can be interrupted under the control of the CPU. T for this case
The description will be given from 7 onward. At t7, the 7c control signal 32 is output as H. When the 7d control signal 33 switches to H at t8, 2 (34) is replaced with L. 7b control signal 35 at t9
To L, and the 7c control signal 32 to L. When the next rising of the 7d control signal 33 comes at t10, 2 (34) rises, and Q1 (36a) switches to the L level so that the clutch is turned off (dashed-dotted line portion).

With these three types of canceling methods, the constant-speed running control can be interrupted, stopped, and terminated, so that there is an advantage that a corresponding method can be selected according to the state of the apparatus. Further, it is possible to quickly follow the cancellation by the driver and the forcible cancellation due to the abnormality detection, and the setting cannot be performed unless a predetermined procedure is taken. Therefore, safety can be improved.

The function will now be described with reference to the flowchart of FIG. In step 101, when the power of the constant-speed traveling device is turned on, various initial settings including an initial reset are performed. In step 102, the vehicle speed signal generating means 1
From the output pulse, the actual vehicle speed Vs is calculated by, for example, a period measurement method. In step 103, the presence or absence of a command signal from the command signal input means 2 is checked. Step 1
In step 04, the presence or absence of a cancel signal from the cancel signal input means 3 is checked. In step 105, it is determined whether or not the actual vehicle speed Vs is equal to or higher than 40 km / h. 40km / h
At low speeds lower than, the vehicle does not run at a constant speed.
If Vs ≧ 40 km / h (YES), step 106
Then, it is checked from the processing result of step 104 whether there is a cancel signal. When the cancel signal is generated, the vehicle does not travel at a constant speed. If there is no cancel input (NO), a command signal is checked from the processing result of step 103 in step 107.

When a command signal is generated, for example, when a constant-speed traveling set signal or a resume signal is generated, constant-speed traveling control can be performed. If there is a command input (YES),
In step 108, a control signal is output to turn on the lamp 11a indicating that the vehicle is running at a constant speed. In step 109, a clutch control flag is set, and in step 110, a control flag indicating that the vehicle is running at a constant speed is set. If there is no command signal in step 107 (NO), it is checked in step 111 whether the vehicle is running at a constant speed. Here, this is equivalent to checking whether the constant speed traveling control flag in step 110 is 1 or not. The constant speed traveling control flag corresponds to a constant speed traveling state detecting means. If the vehicle is traveling at a constant speed (YES), the routine proceeds to step 116, and if not, the routine proceeds to step 114 (NO). Step 10
If the cruise control is prohibited at 5 or 106,
At step 112, a control signal is output to turn off the constant speed running operation lamp. In step 113, it is checked whether or not the vehicle was in the constant speed running state in the previous processing routine. If the vehicle was running at the constant speed last time (YES), the clutch flag is reset in step 114. If the vehicle is not running at the previous constant speed (NO), the process proceeds to step 116. Step 11
At 5, the cruise control flag is reset.

Next, at step 116, a clutch control judgment is made. If it is 1 based on the clutch flags in steps 109 and 114 (YES), a signal to turn on the clutch is output in step 117. On the other hand, if the clutch flag is 0 (NO), a signal to turn off the clutch is output in step 118. Next, in step 119, it is checked whether or not the vehicle is running at a constant speed. This is equivalent to checking the constant speed traveling control flag in step 110 or 115. Flag = 1
If so (YES), a control amount is calculated in step 120. The control amount is to rotate the motor to open and close the Stroll valve so that the stored vehicle speed matches the actual vehicle speed. On the other hand, if the constant-speed running control flag = 0 (NO), the control amount is set to 0 in step 121. In step 122,
The motor drive control pulse corresponding to the control amount is output. For the first time, the motor rotates and the constant-speed running control is performed.
In step 123, the process waits until a predetermined time elapses, and then returns to step 102 again to execute each step in the same manner.

In this flowchart, the same processing can be performed even if the constant speed traveling control flag is included in the clutch flag. Although the DFF control method of FIG. 2 is not shown in this flowchart, it can be realized by executing the procedure shown in the time chart of FIG. Further, the processing shown in FIG. 2 when the constant speed traveling control is interrupted without an external cancel input is similarly performed in steps 111 and 1.
It can be realized by inserting between 14.

Next, an abnormality detection method will be described with reference to FIG. 40 is the A-phase signal of the motor type actuator, 4
1 is a phase signal, 42 is a B phase signal, and 43 is a phase signal. 4
Reference numeral 4 denotes a signal obtained by taking exclusive logic of the phase A and the phase, and reference numeral 45 denotes a signal obtained by taking exclusive logic of the phase B and the phase. Numeral 46 indicates a timing of detecting an abnormality, and indicates a state in which a check is performed at predetermined time intervals. Assuming that the exclusive logic signal of 44 has caused an abnormality at ta (dashed line 44a), an abnormality is detected for each abnormality timing input after ta, and the abnormality can be determined when a predetermined number of times are reached. Phase 4 at tb
If the 1 or B phase 42 becomes abnormal, it can be similarly detected from the exclusive logic signal. Here, the A phase 40 or the phase 43 is H / L
Is output repeatedly, and depending on the input time of the abnormality detection timing, there are cases where the state becomes normal and cases where the state becomes abnormal. However, even in this case, if the count value of the abnormality is different from the count value of the normal, and if the count value of the normal is smaller than the count value of the abnormality, the abnormality can be detected.

Further, each phase often has a delay caused by a filter or the like. This delay may cause the exclusive logic signal to output an incorrect signal for a short time. Further, it is conceivable that this short-time erroneous signal is input in accordance with the abnormality detection timing time of the CPU. However, even in such a case, the problem can be solved by counting up the abnormal counter in an abnormal state and counting down the abnormal counter in a normal state. In addition, this method has an effect of preventing erroneous determination similarly for transient noise.

Next, this abnormality detection method will be described with reference to the flowchart of FIG. This flowchart is for example 1m
It shall be called by interruption every second. That is, the abnormality detection timing of 46 in FIG. 4 is 1 msec.
In step 201, it is checked whether or not the monitor signals do not match. The exclusive logic of the A phase and the phase and the exclusive logic of the B phase and the phase are checked, and the input is at the H level even though both outputs are at the same level, or the input is received even though both outputs are at the different level. If it is at the L level, it is determined that they do not match. If not (YES), at step 202, the abnormality counter ECNT is incremented by two. In step 203, it is determined whether or not the abnormality counter ECNT is equal to or more than a predetermined value. If not less than the predetermined value α (YES), the abnormality counter ECNT is set to α in step 204. Next, at step 205, an abnormal flag is set.

On the other hand, if the monitor signals match in step 201 (NO), an abnormal counter EC
Subtract NT by one. In step 207, it is checked whether the abnormality counter is less than zero. If ECNT <0 (YES), the abnormality counter is set to 0 in step 208. Step 20
In step 9, the abnormality flag is reset. As described above, if the value to be added to or subtracted from the counter is changed between the abnormal state and the normal state, it is possible to cope with a situation in which the normal / abnormal state repeatedly occurs. Also, the configuration is strong against noise.

Embodiment 2 FIG. Next, a second embodiment will be described. Although the method of terminating the constant-speed running control by turning off the clutch when a cancel signal is input or when an abnormality is detected has been described in the first embodiment, the motor unit 8 also needs to be returned to the initial position. The reason for this is that the system is ready to restart the system due to a poor clutch fixation or a temporary failure, and that it is not a failure but a mere cancellation input. In the case of a negative pressure type actuator, it could be initialized simply by stopping the drive,
Some motor-type actuators do not return to the initial position without initialization drive. Further, in a constant-speed traveling device of a type that is controlled using the driving history of the actuator, the initialization is essential. In the initialization, if the motor rotational position at the end of the control is known, it is easy to determine how much reverse rotation should return to the initial position. However, a description will be given of a method that can be easily initialized when an abnormality is detected or even in a device having no function of monitoring the motor rotational position.

FIG. 6 is a time chart showing the correspondence between the initialization of the motor and the drop of the power supply voltage. Reference numeral 50 indicates a state where the power supply voltage is changing. Power supply voltage is 10
Normal if V or more, abnormal if less than 9V, 9-10V
Has a hysteresis of 1V. Reference numeral 51 denotes a change state of the low voltage abnormality counter with respect to the power supply voltage fluctuation 50. The counter value increases below 9 V, decreases above 10 V, and remains constant between 9 and 10 V. Reference numeral 52 denotes a low voltage abnormality flag.
Has been set since it has reached the predetermined value, and reset by te. Reference numeral 53 denotes the state of the lamp 11a in FIG. 1, which is turned off at tc to te. Therefore, tc to te are determined to be abnormal in the constant-speed traveling device, and the constant-speed traveling control is inactive.

Numeral 54 simulates the rotational position of the motor, which can be detected by a sensor or by integrating the motor output pulse. Before tc, a state is shown in which the constant speed traveling control is being performed and the motor is rotating forward and reverse. Since the abnormality is detected at tc, the control is terminated or the interruption processing is performed. In the system simulating the rotation of the motor, the motor can be returned to the initial position by returning the motor slightly more than the motor rotation position at time tc, and can be initialized at td. However, in a system without a monitor signal or sensor, or when an abnormality such as a drop in power supply voltage occurs, initialization cannot be performed as calculated. Thus, this problem is solved by performing initialization control on the assumption that the motor is at the fully open position. te to tf are the values returned from the fully opened position to the initial position. During the times tc to td and te to tf, an initial position return signal is output.

Furthermore, even if a drive for initializing from full open is employed, such as a power supply voltage drop abnormality, the drive may not function due to a drop in power supply. Therefore, when the system returns to normal or after the system power is turned on, the motor is driven to the initial position, so that the control always starts from the initial position (te to t).
f). Also, a logic can be set so that the clutch is turned on for the first time after the motor initialization is completed. As a result, sudden start of constant-speed running control does not suddenly occur, and controllability can be improved.

Next, a low voltage abnormality detection routine will be described with reference to FIG. Step 301 checks whether the power supply voltage is 10 V or more. If it is less than 10 V (NO), it is checked in step 302 whether it is 9 V or more. 9V or more (YE
If S), exit from this routine. If it is less than 9 V (NO), it is determined that the voltage is low, and the low voltage abnormality counter LVCNT is incremented by 1 in step 303. Step 3
At 04, it is checked whether or not this counter has a predetermined value, for example, 25 or more. If it is less than the predetermined value 25 (NO), no processing is performed. If it is equal to or more than the predetermined value (YES), it is determined that there is an abnormality, and a voltage abnormality flag is set in step 305 (set to 1). In step 306, a predetermined value 25 is substituted for the low voltage abnormality counter.

On the other hand, in step 301, 10 V or more (YE
If S), the low voltage abnormality counter is incremented by 1 in step 307.
Subtract. In step 308, it is checked whether this counter is less than zero. If 0 or more (NO), no processing is performed. If it is less than 0 (YES), the voltage abnormality flag is reset in step 309 (set to 0). Step 3
At 10, the low voltage abnormality counter LVCNT is set to 0.
An abnormality in the power supply voltage is detected by performing these series of processes periodically. Further, although 1 was added or subtracted in steps 303 and 307, similar detection is possible even if the value is changed such as adding 2 and subtracting 1.

Next, the relationship between the abnormality detection processing routine and the main flowchart will be described with reference to FIG. Since the processes after step 130 are different from those in FIG. 3, only these processes will be described. After checking each input information in steps 102 to 104, in step 130, a routine for detecting a system abnormality is processed. Specifically, the above-described abnormality of the actuator and abnormality of the power supply voltage are checked. Other abnormalities include disconnection of various inputs and outputs, short-circuits, deterioration of constant-speed traveling controllability, and the like. This processing finally sets and resets the abnormality flag. In step 131, it is checked whether or not the abnormality detection has occurred. Specifically, if the abnormality flag is 1 (YES), the process proceeds to step 112. Conversely, abnormal flag =
If 0 (NO), the process proceeds to step 105.

If an abnormality is detected, the routine proceeds to step 132, where if the vehicle was traveling at a constant speed last time, processing for an abnormality is performed. This abnormal processing particularly means that the motor is driven to return to the initial position. On the other hand, if it is not the last time the vehicle is traveling at the constant speed, the process is not performed. In this state (the last time is not the constant-speed running state), there is no need to perform the processing because the motor remains at the initial position. Further, by inserting the motor initial position return drive when the constant speed traveling control is started for the first time, for example, by inserting step 133 between 108 and 109, the motor can be initialized immediately before the start of the constant speed traveling control. The signal generation in step 133 serves as an initialization signal generating means. In actual software, this is equivalent to step 132. By these motor initializations, control can be started from the throttle valve closed state, and sudden acceleration is eliminated.
Steps 116a and 119a include steps 116 to 118 and steps 119 to 121 in FIG. 3, respectively.

Although the description has been given of the interruption of the constant speed running due to the low voltage, the control is also interrupted similarly when the vehicle speed becomes higher than the first predetermined value with respect to the desired vehicle speed, and is again reduced to the second predetermined value or less. When the current vehicle speed returns to the range, even when the constant speed traveling control is started again, the same can be used. In the flowchart of FIG.
The same processing can be performed by setting the difference V between the actual vehicle speed and the target vehicle speed to 15 km / h, and setting the voltage ≧ 9 V in step 302 to 8 km / h similarly. Also in this case, when returning to the constant-speed running again, the motor is returned to the initial position and the control is performed once, and then the normal running control is started. As a result, the control does not start from the position where the actuator is being driven, and the control performance is improved.

[0039]

The fail-safe device for a constant-speed traveling device according to the present invention is configured as described above, and has the following effects.

According to the fail-safe device for a constant-speed traveling device according to the present invention, when an abnormality is detected in the constant-speed traveling device or when a cancel signal is input, an initialization signal is generated to output a signal for returning the motorized actuator to the initial position. Means, and latch means for actuating the actuator driving means so as to hold the clutch in the off state unless a predetermined procedure for releasing is performed, so that the actuator can be completely turned off. There is an effect that the state can be maintained.

Further, according to the fail-safe device for a constant-speed traveling device according to the present invention, the latch means can be released by pressing C
A combination of a plurality of signals of the PU is required, and a predetermined procedure must be taken to turn on the actuator, and there is an effect that the off state can be maintained.

Further, according to the fail-safe device for a constant-speed traveling device according to the present invention, in order to operate the latch means, it is necessary to input at least one of an abnormality detection signal, a cancel signal, and an output signal from the CPU. And the latched state is maintained even when a command signal is input thereafter, so that the actuator can be easily switched off, the constant speed traveling can be stopped reliably, and this state can be maintained. is there.

According to the fail-safe device for a constant-speed traveling device according to the present invention, the latch means is set by deactivating the display indicating that the constant-speed traveling control is being performed.
There is an effect that the actuator can be simply and reliably turned off.

According to the fail-safe device for a constant-speed traveling device according to the present invention, when the constant-speed traveling control is temporarily interrupted and then restarted, the actuator is returned to the initial position once and then driven at a constant speed. Since the control is started, there is an effect that the control of the actuator can be started from the initial position.

According to the fail-safe device for a constant-speed traveling device according to the present invention, the abnormality of the actuator is detected by comparing the actuator drive signal with the operation state signal, so that the abnormality of the actuator can be easily detected. effective.

Further, according to the fail-safe device for a constant-speed traveling device according to the present invention, the exclusive-phase signals of the respective phases of the stepping motor are mutually exclusive, and the signals are compared with the control signals of the respective phases to determine the actuator. Since the abnormality is detected, there is an effect that the abnormality of the actuator can be easily detected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an entire fail-safe device for a constant-speed traveling device according to a first embodiment of the present invention.

FIG. 2 is a time chart of the latch means according to the first embodiment of the present invention.

FIG. 3 is a main flowchart according to the first embodiment of the present invention.

FIG. 4 is a time chart showing a motor signal according to the first embodiment of the present invention.

FIG. 5 is an abnormality detection flowchart according to the first embodiment of the present invention.

FIG. 6 is a time chart of low voltage detection according to the second embodiment of the present invention.

FIG. 7 is a low voltage detection flowchart according to Embodiment 2 of the present invention.

FIG. 8 is a main flowchart according to Embodiment 2 of the present invention.

FIG. 9 is a block diagram of a conventional device.

[Explanation of symbols]

1 speed signal generating means, 2 command signal input means, 3
Cancel signal input means, 4 exclusive logic signal generation means, 6 microcomputer, 8 motor, 9 latch means, 10 clutch, 11 display means, 12 power supply voltage detection means, 13 reset terminal control circuit.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kazunori Mori F-term (reference) 3D044 AA11 AA14 AA28 AA29 AA30 AB00 AC00 AC03 in Mitsubishi Electric Control Software Co., Ltd. AC26 AC37 AD04 AE01 AE08 AE21 3G065 CA20 CA38 DA05 DA06 GA11 GA46 KA02 3G093 AA01 BA10 BA12 BA23 DA00 DA06 DB05 DB19 EA09 EC02 FA04

Claims (7)

[Claims] 1. A command signal input means for generating a command signal for instructing start of constant speed traveling by external operation or external information, and a cancel signal for instructing termination of constant speed traveling by external operation or external information. A motor-type actuator having a clutch capable of controlling the output of the engine and connecting and disconnecting the engine output control, an actuator driving means for controlling the actuator, and a A microcomputer having an abnormality detection function of detecting an abnormality and outputting a control signal for controlling the actuator in order to perform a desired constant speed traveling; and when the abnormality is detected or the cancel signal is input, the actuator is moved to an initial position. Initialization signal generating means for outputting a signal to return to A fail-safe device for a constant-speed traveling device, comprising: latch means for operating the actuator driving means so as to hold the clutch in an off state unless a procedure is executed. 2. The constant-speed traveling according to claim 1, wherein when the latch means is released, the latch can be released by executing a predetermined procedure based on a combination of a plurality of signals of a microcomputer. Fail-safe device for equipment. 3. The method according to claim 1, wherein when the latch means is operated, it is set when at least one of an abnormality detection signal, a cancel signal, and an output signal from the microcomputer is input, and the latch state is maintained thereafter. The fail-safe device for a constant-speed traveling device according to claim 1 or 2, wherein: 4. A display means for indicating an operation state of the constant-speed traveling device, a state detection means for detecting the constant-speed traveling state, and the state detection means responding to the interruption or the termination of the constant-speed traveling,
The fail-safe device for a constant-speed traveling device according to any one of claims 1 to 3, wherein the display device is deactivated and the latch device is set. 5. A microcomputer which operates to operate the constant-speed traveling device after returning the actuator to the initial position and driving the constant-speed traveling device when the constant-speed traveling control is temporarily interrupted and the control is started again. The fail-safe device for a constant-speed traveling device according to claim 1. 6. A microcomputer having a function of detecting an actuator abnormality by comparing an actuator driving control signal output from the microcomputer itself with a signal indicating an actuator operating state. The fail-safe device for a constant-speed traveling device according to any one of claims 1 to 5. 7. A microcomputer is provided with a stepping motor type actuator based on a four-phase control signal.
An exclusive logic signal between the opposite signals of each phase is input from among the phase control signals, and an abnormality of the actuator is detected by comparing the four-phase control signal with the exclusive logic signal. 7. The fail-safe device for a constant-speed traveling device according to claim 6, wherein: