JPH0672182A - Constant speed travel device for vehicle - Google Patents

Abstract

PURPOSE:To provide a constant speed travel device for a vehicle high in reliability without the generation of operation failure. CONSTITUTION:The specified offset quantity is added to the output, corresponding to the lower limit opening, of a throttle opening detector 12d to set the control lower limit opening, and the specified offset quantity is deducted from the output, corresponding to the upper limit opening of a throttle valve 11, of the throttle opening detector 12d to set the control upper limit opening. Accordingly, in the case of opening the throttle valve 11 by the normal rotatory driving of a d.c. motor 12a, the d.c. motor 12a can be stopped in the upper limit stop position, that is, at the control upper limit opening short of the upper limit opening. In the case of closing the throttle valve 11, the d. c. motor 12a can be stopped in the lower limit stop position, that is, at the control lower limit opening short of the lower limit opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle constant speed traveling device.

[0002]

2. Description of the Related Art An electric actuator (hereinafter simply referred to as an actuator) for controlling a throttle opening of a vehicle constant-speed traveling device operates by reciprocal rotation of an operating shaft to which the output of a servo motor is transmitted, and a return spring when the operation is released. In some cases, the output shaft is returned to the lower limit stopper position. If the servo motor continues to be driven even when the operating shaft reaches the upper limit or the lower limit stopper position, the servo motor may be burned due to the motor lock or parts such as the transmission gear may be damaged. Therefore, place the limit switch just before the upper and lower limit stopper positions,
Before the operating shaft reaches the upper limit or the lower limit stopper position, the power supply to the servo motor is cut off.

[0003]

However, an adjustment process for reliably operating the limit switch is required, which not only increases man-hours and cost, but also when foreign matter adheres to the contact of the limit switch, There is a problem that malfunction occurs and the reliability of the vehicle constant speed traveling device is impaired. The present invention has been made to solve the above problems, and an object of the present invention is to provide a highly reliable vehicle constant speed traveling device that does not cause malfunction.

[0004]

As a concrete means for achieving the above object, the throttle valve is reciprocally rotated between an upper limit stopper position and a lower limit stopper position by an output of a servo motor transmitted through an electromagnetic clutch. In a vehicle constant speed traveling device equipped with an electric actuator for controlling the throttle opening degree having an actuation axis for controlling the opening degree, the electronic control unit for inputting the detection value of the potentiometer for detecting the actuation angle of the actuation axis is turned off. A constant-speed traveling device for a vehicle, characterized in that means for activating the servomotor is cut off before the operating shaft reaches the upper limit stopper position and the lower limit stopper position based on the detected value. Provided.

In the electronic control unit of the above-mentioned vehicle constant speed traveling device, when the ignition switch is turned on, a predetermined offset amount is added to the detection value of the potentiometer with respect to the operating shaft returned to the lower limit stopper position, so that the servo motor can be controlled. You may provide the setting means which sets the control lower limit opening degree which interrupts | blocks energization. Then, when the setting means sets the control lower limit opening, if the difference between the detection value of the potentiometer for the lower limit stopper position and the value at the previous setting is a predetermined value or more, it is determined to be a failure. Means and prohibiting means for prohibiting control relating to constant speed traveling when the determination means determines that there is a failure may be provided. Further, a setting means may be provided for subtracting a predetermined offset amount from the value of the potentiometer with respect to the adjusted upper limit opening to set the control upper limit opening for cutting off the power supply to the servo motor.

[0006]

In the vehicle constant-speed traveling device having the above structure, the potentiometer detects the working angle of the working shaft that reciprocally rotates between the upper limit stopper position and the lower limit stopper position to control the opening of the throttle valve. Based on this, the energization cutoff means cuts off the energization to the servo motor before the operating shaft reaches the upper limit stopper position and the lower limit stopper position.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram of a vehicle constant-speed traveling device mounted on an automobile. The throttle valve 11 is an actuator 12 or an accelerator pedal 1.
The opening degree is adjusted by the operation of 3. The actuator 12 is a DC motor 12a which is a servo motor, an electromagnetic clutch 12b, an operating shaft 12c, a throttle opening detector 12
d and the electromagnetic clutch 12b are turned off, and the DC motor 1
When the connection between 2a and the operating shaft 12c is released, the operating shaft 1
2c to the lower limit stopper position.

When the electromagnetic clutch 12b is turned on and the DC motor 12a and the operating shaft 12c are connected to each other in a driving state, when the DC motor 12a rotates, the throttle valve 1
The opening degree of 1 is adjusted. The throttle opening detector 12d is composed of a potentiometer and has a rotational movement amount of the operating shaft 12c that is in a relative relationship with the opening of the throttle valve 11.
That is, the current throttle opening NT (hereinafter simply referred to as NT) which is the actual opening of the throttle valve 11 at that time is detected. The throttle opening detector 12d sets the upper limit opening NU (see FIG. 2) which is the upper limit stopper position so that the output becomes a predetermined value just before the fully open point of the throttle valve 11. A control circuit 14 for driving and controlling the actuator 12 is composed of a microcomputer, and includes a main control unit 14a and a servo motor control unit 14
b, the servo motor drive unit 14c and the electromagnetic clutch drive unit 14d, and receives power supply from the vehicle-mounted battery 15.

The main control section 14a is a vehicle speed sensor 16 composed of a magnet and a reed switch for generating an on / off signal having a period proportional to the traveling speed of the vehicle, a target vehicle speed set by a driver and constant speed traveling control. Each signal is input from a set switch 17 for instructing the start of the operation and a cancel switch 18 which is turned on in association with the depression operation of the brake pedal and releases the constant speed traveling. The main control unit 14a has a control lower limit opening setting function, an initial opening calculation function, a target throttle opening calculation function, and a connection / disconnection control function.

The control lower limit opening setting function takes in the value of the throttle opening detector 12d and sets the control lower limit opening NA (see FIG. 2) when the ignition switch is turned on.
The initial opening calculation function responds to an ON signal based on an operation from the set switch 17, and calculates an actual traveling speed of the vehicle at that time calculated based on a signal input from the vehicle speed sensor 16 (hereinafter referred to as an actual vehicle speed. ) SPDN is an actuator 12 that is uniquely determined according to the target vehicle speed SPDM.
The initial opening degree TΦi is calculated as the basic control amount. The target throttle opening degree calculation function is a target throttle opening degree ST (hereinafter simply referred to as S as a target adjustment amount of the actuator 12).
(T). The connection / disconnection control function is performed by turning on / off the electromagnetic clutch 12b.
It controls the connection and disconnection of the throttle valve 11.

The servo motor control unit 14b inputs ST calculated by the main control unit 14a and NT of the throttle valve 11 detected by the throttle opening detector 12d, and increases based on both the openings ST and NT. The control amount of the speed signal MOi or the deceleration signal MCi is calculated.
Then, the DC motor 12a is rotationally driven by a control signal obtained by amplifying the signal by the servo motor drive unit 14c. In the case of acceleration, when the NT reaches the control upper limit opening degree NB, the DC motor 12a is not driven to the forward rotation side. Further, in the case of deceleration, when NT reaches the control lower limit opening NA, the DC motor 12a is not driven to the reverse rotation side.

The acceleration and deceleration signals MOi and MCi are
Output from the servo motor control unit 14b to the servo motor control unit 14c, the DC motor 12
It is a control signal for controlling the opening degree of the throttle valve 11 by reversing a in the forward and reverse directions, and both output a signal having a logical value of "1" or "0". When the DC motor 12a is normally rotated, the speed increasing signal MOi is set to "0", the deceleration signal MCi is set to "1", and when the DC motor 12a is rotated in the reverse direction, the speed increasing signal MOi is set to "1", the deceleration signal MCi is set to "0", and the DC motor 12a is stopped. In some cases, both the acceleration and deceleration signals MOi and MCi are set to "1".

The electromagnetic clutch drive section 14d has a clutch control signal CL output from the main control section 14a.
Based on T, the electromagnetic clutch 12 of the actuator 12
Control b on / off. The clutch control signal CLT is a signal having a logical value of "1" or "0", and when the electromagnetic clutch 12b is turned on to connect the actuator 12 and the throttle valve 11, the clutch control signal CLT is used.
Is set to "0" and the electromagnetic clutch 12b is turned off to disconnect the actuator 12 and the throttle valve 11, the clutch control signal CLT is set to "1".

The operation of the constant speed traveling device configured as described above will be described below according to the program operation executed by the control circuit 14. FIG. 4 is a flowchart showing the contents of the program operation. First, when the ignition switch is turned on and turned on (step 100), the NT of the actuator 12 at the lower limit stopper position is fetched and set as the lower limit opening N ₁ (step 10).
1). Then, the lower limit opening N ₁ and N _{1 (n-1)} (previous lower limit opening) are compared (step 102), and if the difference is larger than the set value α, control is prohibited (step 104). If it is smaller than the set value α, the offset amount V ₁ is added to the output of the throttle opening detector 12d corresponding to the lower limit opening N ₁ ,
Set the control lower limit opening NA. Further, the control upper limit opening NB is set by subtracting a predetermined offset amount V ₂ from the output of the throttle opening detector 12d corresponding to the upper limit opening NU of the throttle valve 11 (step 10).
3).

Now, when the vehicle is in a traveling state, the control circuit 14 calculates the actual vehicle speed SPDN of the vehicle at that time based on the signal from the vehicle speed sensor 15 input to the main control section 14a, and controls the same. The data is stored in the memory built in the unit 14a (step 105). Then, it is determined whether or not the constant speed control flag FDO (hereinafter referred to as FDO) built in the main control unit 14a is set to "1" (step 106). This FDO
Is a flag that indicates whether or not the vehicle is in constant speed traveling control (hereinafter referred to as constant speed mode), and is set to "1" in the constant speed mode based on the processing operation described later. , Is set to "0" except in the constant speed mode.

When FDO is set to "0", the main control section 14a is operated by the set switch 17
It is determined whether or not the operation has been performed, that is, whether or not the driver has turned on the set switch 17 in order to perform constant speed traveling (step 130). Then, when the set switch 17 is not operated, the process returns to step 105 again. Therefore, the main control unit 14a determines the actual vehicle speed SPDN at that time.
Is calculated, and the actual vehicle speed SPDN calculated and stored previously is updated, and the operation of the set switch 17 is awaited.

When the set switch 17 is operated, the main control section 14a sets the actual vehicle speed SPDN calculated in step 105 as the target vehicle speed SPDM in response to the ON signal of the set switch 17, and Target vehicle speed SPDM to main control unit 1
It is stored in the memory in 4a. And the target vehicle speed SP
An initial opening TΦi of the actuator 12 that is uniquely determined for DM is set as a corrected initial opening TΦN.
The initial opening TΦi with respect to the target vehicle speed SPDM is calculated based on the data stored in advance in the memory of the main control unit 14a. further,
The FDO is set to "1" to set the constant speed mode, and the main control unit 14a causes the electromagnetic clutch drive unit 14d to output the clutch control signal CL having the logical value "0".
T is output (step 131) and the process returns to step 105.

In response to the clutch control signal CLT in step 131, the electromagnetic clutch drive section 14d.
Turns on the electromagnetic clutch 12b, connects the DC motor 12a and the operating shaft 12c, and enables the actuator 12 to adjust the opening of the throttle valve 11. Also,
When the FDO is set to "1", the main controller 14a determines that the constant speed mode is set (step 10).
6) It is determined whether or not the cancel switch 18 has been operated, that is, whether or not the cancel switch 18 has been turned on by depressing the brake pedal to cancel the constant speed mode already in the constant speed mode (step 107).

When the cancel switch 18 is operated to release the constant speed mode, the main controller 14a
Outputs a clutch control signal CLT having a logical value of "1" to the electromagnetic clutch drive unit 14d and sets FDO to "0" (step 125). Therefore, the electromagnetic clutch drive unit 14d receives the clutch control signal C
In response to the LT, the electromagnetic clutch 12b is turned off, the connection between the DC motor 12a and the operating shaft 12c is cut off, the opening adjustment operation of the throttle valve 11 by the actuator 12 is released, and the return spring 12e causes the operating shaft to move. 12c is returned to the lower limit stopper position (not shown). As a result, the opening of the throttle valve 11 is adjusted by operating the accelerator pedal 13, and the main control unit 14 returns to the processing operation of step 105 and waits for the setting of the constant speed mode by operating the set switch 17 again. To do.

On the other hand, when there is no operation for releasing the constant speed mode, the main control unit 14 sets the target vehicle speed SPDM set in step 131 and step 10
Deviation from the actual vehicle speed SPDN calculated in step 5 (= SPDM-
SPDN) is calculated, and the correction initial opening degree calculation processing operation is executed (step 110). This correction initial opening degree calculation processing operation is performed in the step 131 or in the constant speed mode by using the correction initial opening degree TΦN already set in step 110.
It is a process of updating the initial opening degree TΦN by making a correction according to the deviation δ. The correction amount CTΦ as the correction integration amount is determined by the correction line L according to the deviation δ, as shown in FIG.

The correction line CTΦ with respect to the deviation δ based on the correction line L is calculated based on the data stored in advance in the memory in the main control unit 14a. Then, the correction initial opening calculation processing operation in step 110 is performed by the correction amount C calculated according to the deviation δ from the correction line L.
A value obtained by adding TΦ and the corrected initial opening TΦN is set as a new corrected initial opening TΦN (= TΦN ± CTΦ).

When the new corrected initial opening TΦN is set as described above, the main control unit 14a calculates ST which is the target throttle opening (step 111).
The calculation of ST is performed by the correction initial opening T which is the integral control.
Unlike the calculation of ΦN, this is a calculation of proportional control. A predetermined constant G is added to the deviation δ (= SPDM-SPDN) obtained in step 108, and added to the corrected initial opening TΦN obtained in step 110 to obtain ST (= TΦN + G ·
Find δ). Then, the main control unit 14 takes in the calculated ST (step 112) and outputs it to the servo motor control unit 14c.

The servo motor control section 14c inputs NT detected by the throttle opening detector 12d (step 112) and subtracts NT from ST to determine whether the value is positive or negative (step 113). .
When ST> NT, it is necessary to increase the engine speed, and when NT is smaller than the control upper limit opening NB (NO in step 114), the servo motor control unit 1
4b resets the acceleration signal MOi from "1" to "0" while keeping the deceleration signal MCi set to "1" (step 115). Then, the direct current motor 12a is driven in the normal direction by the control signal of the servo motor drive unit 14c, and the opening degree of the throttle valve 11 is opened toward ST.

When the speed-up signal MOi is reset to "0" as described above, the servo motor control section 14b
Indicates that (ST-NT) is a predetermined reference value (hereinafter referred to as a dead zone, a value converted into a throttle opening in a region set to improve the durability of the DC motor 12a) DZ (hereinafter simply DZ). It is determined whether or not (step 1)
16). Then, if ST-NT ≦ DZ, the control circuit 14 returns to the step 105, and the step 105
The following processing operations are executed. If ST-NT> DZ, the servo motor control unit 14b calculates the drive time T of the DC motor 12a, that is, the time for setting the speed-up signal MOi from "0" to "1" (step 11).
7).

The driving time T is (ST-NT-DZ)
Is calculated by adding a predetermined constant DG. The drive time T is set in the timer built in the servo motor control unit 14b, and the servo motor control unit 14b waits until the drive time T set in the timer expires (step 12).
2). When the timer times out, the servo motor control unit 14b causes the acceleration and deceleration signals MOi, MCi
Are both set from "0" to "1" (step 12)
3). When the speed increasing signal MOi is set from "0" to "1", the control signal from the servo motor drive unit 14c causes
The DC motor 12a is stopped and the throttle valve 11 is maintained at the opening degree at that time. Then, the control circuit 14 returns to the step 105 and executes the above-mentioned processing operation again.

On the other hand, in step 113, ST>
In the case of NT, it is necessary to lower the engine speed, and NT is larger than the control lower limit opening NA (step 118
In the case of NO), the servomotor control unit 14b keeps the speed increasing signal MOi set to "1" and the deceleration signal Mi remains unchanged.
Reset Ci from "1" to "0" (step 11)
9). Then, the DC motor 12a is reversely driven by the control signal of the servo motor drive unit 14c, and the opening degree of the throttle valve 11 is closed toward ST.

When the deceleration signal MCi is reset to "0" as described above, the servo motor control section 14b
Determines whether the value obtained by subtracting ST from NT (= NT-ST) is greater than or equal to the predetermined DZ (step 11).
6). When ST-NT ≦ DZ, the control circuit 1
4 returns to step 105 and executes the processing operation of step 105 and thereafter. When NT-ST> DZ, the servo motor control unit 14b calculates the drive time T of the DC motor 12a, that is, the time for setting the deceleration signal MCi from "0" to "1", as in step 117. (Step 121).

The driving time T is (NT-ST-DZ)
Is calculated by adding the constant DG to the value of. The drive time T is set in a timer built in the servo motor control unit 14b, and the servo motor control unit 14b sets the drive time T set in the timer.
Waits until the time is up (step 122).
When the timer times out, the servo motor control unit 14b sets both the speed-up and deceleration signals MOi and MCi from "0" to "1" (step 123). When the speed increasing signal MOi is set from "0" to "1", the DC motor 12a is stopped by the control signal of the servo motor drive unit 14c and the throttle valve 11 is held at the opening degree at that time. Then, the control circuit 14 executes the step 1
Returning to 05, the processing operation described above is executed again.

In step 113, ST = N
In the case of T, that is, when the engine speed is maintained as it is, the DC motor 12a is stopped and the throttle valve is opened to its opening state (TN = ST) so that the actual vehicle speed SPDN continues to maintain the target vehicle speed SPDM. 11 is retained, the process returns to step 105, and the processing operation described above is executed again.

In the above embodiment, the control lower limit opening NA is set by adding the offset amount V ₁ to the output of the throttle opening detector 12d corresponding to the lower limit opening N ₁ . Further, the control upper limit opening NB is set by subtracting a predetermined offset amount V ₂ from the output of the throttle opening detector 12d corresponding to the upper limit opening NU of the throttle valve 11. Therefore, when the throttle valve 11 is opened by the normal rotation driving of the DC motor 12a, the DC motor 12a can be stopped at the control upper limit opening NB before the upper limit opening NU which is the upper limit stopper position. When closing the throttle valve 11, the DC motor 12a can be stopped at the control lower limit opening NA before the lower limit opening N ₁ which is the lower limit stopper position.

Further, when the control lower limit opening NA is set, if the difference between the detected value of the potentiometer for the lower limit opening N ₁ which is the lower limit stopper position and the value at the previous setting is a predetermined value or more, Since it is determined that there is a failure and control relating to constant speed traveling is prohibited, an unexpected situation resulting from a failure of the constant speed traveling device can be prevented. When determining the failure of the lower limit opening, the determination level of the absolute value of the lower limit opening N ₁ may be used, and the comparison determination result with the previous lower limit opening N _{1 (n-1)} may be used. You may use together. Also, the actuator 1
The correspondence relationship between the operating rotation angle of No. 2 and the rotation angle of the throttle valve 11 can be made as close as possible, and there is an advantage that the responsiveness when the constant speed mode is set and the vehicle speed maintenance performance when climbing a slope are improved.

[0032]

The vehicle constant-speed traveling device of the present invention has the above-mentioned structure, and the working angle of the working shaft for controlling the opening degree of the throttle valve by reciprocally rotating between the upper limit stopper position and the lower limit stopper position, Based on the value detected by the potentiometer and the detected value, the energization interrupting means surely interrupts energization to the servo motor before the operating shaft reaches the upper limit stopper position and the lower limit stopper position. No limit switch is required to prevent the servo motor from being continuously driven even when the lower limit stopper position is reached.
It is possible to completely prevent inconveniences such as a motor lock caused by a malfunction of the limit switch, a servo motor being burned, and parts such as a transmission gear being damaged.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of a vehicle constant speed traveling device.

FIG. 2 is a characteristic diagram showing a relationship between an opening of an actuator and an output of a throttle opening detector.

FIG. 3 is a correction diagram showing a relationship between a deviation and a correction amount.

FIG. 4 is a flowchart showing the content of a program operation executed by a control circuit.

FIG. 5 is a flowchart showing the contents of a program operation executed by a control circuit.

[Explanation of symbols]

11 ... Throttle valve 12 ... Actuator 12a ... DC motor (servo motor) 12b ... Electromagnetic clutch 12c ... Actuating shaft 12d ... Throttle opening detector (potentiometer) 14 ... Control Circuit 14a ... Main control unit 14b ... Servo motor control unit 14c ... Servo motor drive unit 14d ... Electromagnetic clutch drive unit N ₁ ... Lower limit opening (lower limit stopper position) NU ... Upper limit Opening (upper limit stopper position) NA ... Control lower limit opening NB ... Control upper limit opening

Claims (4)

[Claims] 1. A throttle opening control electric motor having an operating shaft for controlling the opening of a throttle valve by reciprocally rotating between an upper limit stopper position and a lower limit stopper position by the output of a servo motor transmitted through an electromagnetic clutch. In a vehicle constant-speed traveling device equipped with an actuator, an electronic control unit for inputting a detection value of a potentiometer for detecting the working angle of the working shaft is provided with an energization interruption means,
A constant speed traveling device for a vehicle, characterized in that power supply to the servomotor is cut off before the operating shaft reaches the upper limit stopper position and the lower limit stopper position based on the detected value. 2. A control for adding a predetermined offset amount to a detection value of the potentiometer with respect to the operating shaft returned to a lower limit stopper position when the ignition switch is turned on, to cut off the energization of the servo motor to the electronic control unit. The vehicle constant speed traveling device according to claim 1, further comprising setting means for setting a lower limit opening degree. 3. When the setting means sets the control lower limit opening, if the difference between the detected value of the potentiometer for the lower limit stopper position and the value at the previous setting is a predetermined value or more, it is determined as a failure. 3. The vehicle constant speed traveling device according to claim 2, further comprising: a determining unit; and a prohibiting unit that prohibits control relating to constant speed traveling when the determination unit determines that the vehicle is out of order. 4. The electronic control unit is provided with setting means for setting a control upper limit opening for cutting off the power supply to the servo motor by subtracting a predetermined offset amount from the value of the potentiometer for the adjusted upper limit opening. The constant speed traveling device for a vehicle according to any one of claims 1, 2 and 3.