JPS6349541A - Constant speed traveling device - Google Patents

Abstract

PURPOSE:To obtain a desired gain characteristic by obtaining an analog signal corresponding to a gain characteristic based on a vehicle speed signal and controlling the drive of a DC motor in accordance with the phase difference between a reference pulse signal obtained by converting said analog signal and a motor speed pulse signal. CONSTITUTION:In the captioned device in which a throttle valve 6 is operated by a motor-driven actuator 1 driven by a DC motor to control a throttle valve opening, a broken line approximation circuit 20 receives a vehicle speed signal from a vehicle speed detector 19 and outputs an analog signal corresponding to a throttle valve opening speed to a vehicle speed characteristic. Also, a voltage/frequency converter 21 obtains a reference pulse signal from said analog signal, and a phase comparator 22 generates an output pulse having a pulse width proportionate to the phase difference between the reference pulse signal and a motor speed pulse signal. And, the output pulse is integrated 27, the integrated value is pulse-width modulated 28 with a triangular wave, etc., and the DC motor is controlled via a driver 29 to variably control the valve opening speed of the throttle valve 6.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a constant-speed traveling system that controls the throttle valve of an automatic vehicle by %FIJ using an electric motor type actuator. This invention relates to a constant speed traveling device that improves controllability by making the speed variable (variable gain control).

[Conventional technology]

Conventionally, in this type of motor type constant speed traveling device, the throttle opening speed versus vehicle speed characteristic (hereinafter referred to as gain characteristic) has been provided with a substantially flat characteristic (-foot gain characteristic).

However, depending on the type of car, for example, a spora car has more margin in driving capacity than a general commercial vehicle or a normal passenger car, and therefore has excellent acceleration performance, so even in a constant speed driving system, it has high responsiveness. Therefore, it is desired that the gain characteristic be close to linear with respect to vehicle speed.

Furthermore, in consideration of the fact that the load 11iLf is relatively large, commercial vehicles do not require high responsiveness like sports vehicles, but rather flat gain characteristics are desired over the entire vehicle speed range.

Furthermore, normal passenger cars are required to have linear characteristics similar to those of sports cars up to the medium speed range, and saturation or descending characteristics are desirable in the high speed range from the viewpoint of driving stability.

[Problem that the invention seeks to solve]

As described above, it is not always possible to obtain the optimum gain characteristic corresponding to each vehicle type.

The present invention has been made to solve these problems, and an object of the present invention is to provide a variable gain type constant speed traveling device that can provide desired gain characteristics for each vehicle type.

[Means for solving problems]

The constant speed traveling device according to the present invention includes a polygonal line approximation circuit that converts a vehicle speed signal into an approximate output with a desired gain characteristic, a voltage/frequency converter that converts this approximate output into a frequency, and an output of the voltage/frequency converter. and means for performing phase synchronization control by comparing the motor speed detection pulse signal and the motor speed detection pulse signal.

[For production]

In this invention, a vehicle speed signal is input to a polygonal line approximation circuit, where it is converted to an approximate output using an analog voltage with a desired gain characteristic, and this approximate output is input to a total voltage/frequency converter to be converted into a frequency, and then the phase As the reference input of the comparator,
On the other hand, a detection pulse signal corresponding to the motor speed is input to a phase comparator as a comparison input, and a so-called PLL control of phase synchronization control is performed using the reference input and the detection pulse signal to control the motor speed.

〔Example〕

Next, a specific embodiment of the constant speed traveling device of the present invention will be described. FIG. 1 shows a system block diagram of a motor-type constant-speed traveling device as an embodiment of the present invention, where 1 is a motor-type actuator, and 2 is a wire take-up reel. A wire 3a is wound around the wire take-up reel 2, and the tip of the wire 3a is connected to a throttle valve 6 via a throttle link 5a.

Further, the accelerator pedal 4 is also connected to the throttle valve 6 via a wire 3b and a throttle link 5b'r. This accelerator pedal 4 and actuator I
K! ,9. The throttle opening degree of the throttle knob 6 is adjusted.

The rotational speed of the engine 7 changes depending on the throttle opening, and the rotational speed of the engine 7, that is, the vehicle speed is indicated by a speedometer 8. actuator l
is controlled by a control unit 9. In addition, it is a 10 switch number or an operation panel.

In this figure, a motor actuator 1 acts on a throttle link 5a to maintain a predetermined throttle opening of a throttle valve 6 regardless of the operation of an accelerator pedal 4, thereby keeping the vehicle speed constant. It is possible to control the speed at a constant speed.

FIG. 2 shows a block diagram of the control system of the first embodiment of the apparatus of the present invention, and shows a part of the internal configuration of the control unit 9 in FIG. 1. In this figure 2, 1
Reference numeral 9 indicates a vehicle speed detector, which is attached to the drive shaft of the engine and outputs an analog voltage proportional to the vehicle speed.

This output is input to a broken line approximation circuit 20. This broken line approximation circuit 2o inputs the vehicle speed signal,
An analog signal corresponding to a desired gain curve trap is output to a voltage/frequency (hereinafter referred to as V/F) converter 21.

This V/F converter 21 inputs the analog signal obtained from the broken line approximation circuit 2o, converts it into a pulse frequency,
It is output as a reference pulse signal for the phase and phase comparator 22 of the next stage.

The phase comparator 22 uses the above reference /J? The pulse signal and the motor speed pulse signal obtained from the encoder 26 attached to the shaft of the DC motor 25 are input as comparison input signals to perform synchronization control.

That is, the phase difference between both signals is detected, and a pulse signal (PLL output) having a pulse width proportional to this phase difference is output.

This pulse signal is applied to the operational amplifier AI of the next stage integration circuit 27.
It is designed to be input to the (-) input terminal of O via a resistor R3'.

The input terminal of this operational amplifier AIO is grounded via a resistor R2, and is connected to a voltage of 10 Vcc via a resistor R1e.
K is connected. Output terminal of operational amplifier AIO and (-)
A capacitor C1 is connected between the input terminals.

The output terminal of the operational amplifier AIO is connected to the (-) input terminal of the operational amplifier All of the PWMC pulse width modulation (PWMC pulse width modulation) circuit 28.
- It is designed to be input through.

The output of the triangular wave or sawtooth wave oscillator 23 is input to the (+) input terminal of the amplifier All through a resistor R5. The output of this amplifier All is resistor R18? The rotational direction discriminator 24 is then sent to the rotational direction discriminator 24.

The output of this rotational direction discriminator 24 is output from inverters IN1 to I
N4 and resistors R6 to R9, respectively, to the transistor T.
r! , Try *Trs e Try. The transistors Tr1 to Tr8 are the main components of the motor driver 29, and the emitters of the transistors Trl and Try are grounded, and the collectors of both transistors Trl and Tr2 are connected to the t-atom VER through the resistors RIO and RII''It, respectively.
It is also connected to the bases of transistors Tr4 and Trs via resistors R13 and R12.

The emitter of the transistor Trs is connected to the power supply VEE, the emitter of the transistor Tr4 is grounded, and the collectors of both transistors Tr3 and Tr4 are connected to the collectors of the transistors Trs and Try via the DC motor 25.

Diodes D1 to D4 are connected between the collectors and emitters of transistors Tr3 to Tr-, respectively.

Transimeta T? The emitter of I is connected to the power supply +VEZ, and the emitter of transistor Tr@ is grounded.

The emitters of the transistors Try + Trs are grounded, and the collectors are connected to resistors R16 and R17, respectively.
is connected to the power supply +"lf'EE through the transistor Trs
, connected to the base of Trs.

Next, this I! The operation of the control system shown in FIG. 2 will be explained.

The vehicle speed detector 19 sends an analog voltage proportional to the vehicle speed to the polygonal line approximation circuit 20, which sends an analog signal corresponding to a desired gain curve to the V/F converter 21, which converts the analog signal to V/F. The signal is converted into a nozzle frequency by the converter 21 and outputted to the phase comparator 22 as a reference signal.

On the other hand, the motor speed pulse signal obtained from the encoder 26 is sent to the phase comparator 22, and the phase comparator 22 compares the phase of this motor speed pulse signal with the comparison input signal to determine the phase difference between the two. is detected, and a pulse signal having a pulse width proportional to this phase difference is sent to the integrating circuit 27.

This integration cycle 27 converts it into an analog value again, inputs it to the next stage PWM circuit 28, modulates it with the output of the triangular wave or sawtooth wave oscillator 23 of a predetermined frequency, and converts it into an analog value proportional to the analog output value of the integration circuit 27. Pulse signal (PWM
output] is output.

This PWM signal is input to the rotation direction discriminator 24 at the next stage, which outputs four drive signals, and the transistor T
The next stage motor driver circuit 29, which mainly consists of rl to Tr6, is driven and controlled.

The motor driver circuit 29 performs phase synchronization control on the motor speed so as to match the gain characteristic obtained by the broken line approximation circuit 20, and also controls the rotation direction to match.

FIG. 3 is a block diagram of the control system of the second embodiment of the constant speed traveling device of the present invention, and is a speed deviation detection circuit for detecting the difference between the 30Fi set vehicle speed and the actual vehicle speed. When it becomes below a predetermined level, it acts on the next stage switching circuit 31 to open the analog switch Kl and close the analog switch 2, so that a constant voltage is applied to the PWM circuit 28. Variable control is disabled and switches to constant gain control. Resistors R19 and R20 represent a resistor circuit for creating a reference voltage for constant gain control. Components other than those described above are the same as those in the embodiment shown in FIG. 2, and will therefore be omitted.

FIG. 4 shows the broken line approximation circuit 20 in FIGS. 2 and 3.
, A1 is an input amplifier, A7 is a specific embodiment of
is a deba amplifier, and A2 to 86 are addition B that performs broken line approximation.
This shows that.

A vehicle speed signal from the vehicle speed detector 19 is input to the (-) input terminal of the input amplifier AI through the resistor R122' from the input terminal IN, and the input terminal is grounded. A resistor R121 is connected between the (-) input terminal and the output terminal of the input amplifier A1.

The output of this operational amplifier A1 is transmitted to each of the adders A2 to A6 (
-) input terminals through resistors R111-Rl15, and the added values E1-E5 are inputted to each (-) large output terminal through variable resistors R116-R120 and resistors R123-R127t-, respectively. It has become so.

The added value El-E5 is the variable resistor R116 to R12, respectively.
0, each variable resistor R116 to R1
20 is connected between the power supply VCC and ground.

The output terminals of adders A2 to A6 each have a diode D11.
and DI2. DI3 and DI4...DI9 and D20
connected between each connection point. Diode DI 1
．． DI 3. DI 5. DI 7. The anode of DI 9 is connected to the j-) input terminals of adders A2 to A6.

Diode DI 2. DI 4. DI 6. DI 8
Each cand of D20 is connected to each connection point between resistors R106 to R110 and variable resistors R101 to R105. Resistors R106 to R110 and variable resistors R101 to R10
The series circuit with 5 is connected to the (-) input terminal of the adder A2-86 and the (-) input terminal of the output amplifier A7.

The input terminals of each of the adders A2 to A6 and the output amplifier A7 are grounded. A resistor Ro is connected between the (-) input terminal and the output terminal of the output amplifier A7.

This output terminal is connected to output terminal 0UTK.

The variable resistor RXN is connected between the output terminal of the input amplifier AI and the (-) input terminal of the output amplifier A7.

&K, the function of this broken line approximation circuit will be described.

Now, assuming that the added values of the adders A2 to A6 are E1 to E5, the output characteristics of this broken line approximation circuit are as shown in FIG. 5, and the slopes S1 to S5 in each section are determined by the following equation.

S 1 = Ro () ”・(I
IIN This output characteristic corresponds to the gain characteristic, and by changing the constant (resistance value), in addition to the above-mentioned positive slope, 0 or negative slope can also be selected.

Figure 6 shows the gain characteristics of a generally desired constant-speed traveling device, where human is a sports car, B is a commercial vehicle, and C is a normal passenger car.This can be easily done by using the aforementioned polygonal line approximation circuit. This can be realized.

〔Effect of the invention〕

As described above, the present invention inputs a vehicle speed signal to a fully folded line approximation circuit to obtain an analog output signal corresponding to gain characteristics, and inputs this analog signal to a voltage/frequency converter to convert it into a reference pulse signal. This reference pulse and the pulse signal obtained from the engoder attached to the motor shaft are input to a gold phase comparator to obtain an output pulse signal with a pulse width proportional to the phase difference between the two signals. After passing through an integrating circuit, PWM modulation is performed with a triangular wave or sawtooth wave, and the motor is driven and controlled by this modulated pulse, so the speed of the motor is controlled in accordance with the gain characteristics.
A constant speed traveling device having desired gain characteristics can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the constant speed traveling device of the present invention, FIG. 2 is a block diagram of the control system in the constant speed traveling device of the present invention, and FIG. 3 is a control system for the constant speed traveling device trap of the present invention. System a! FIG. 4 is a circuit diagram of the Fr line approximation circuit in both systems of FIG. 2 and FIG. FIG. 6 is a diagram showing an example of vehicle speed versus gain characteristics. l...actuator, 4...accelerator pedal, 6
... Throttle valve, 7... Engine, 8...
Scheidometer, 19... Vehicle speed detector, 20... Broken line approximation circuit, 21... Voltage/frequency converter, 22...
- Phase comparator, 23... triangular wave oscillator, 24... rotational direction discriminator, 25... DC motor,
26...Encoder, 27...Integrator circuit, 28...
- PWM modulator, 29... motor driver. Note that the same reference numerals in the drawings indicate the same or equivalent parts. Agent Masuo Oiwa + 3R-Nagi procedural amendment (voluntary) May 9, 1988 Expenses

Claims (2)

[Claims] (1) In a constant speed driving system that operates a throttle valve using an electric actuator driven by a DC motor and controls the throttle opening to maintain a constant vehicle speed,
A polygonal line approximation circuit that inputs a vehicle speed signal and obtains an analog output signal corresponding to the throttle opening speed vs. vehicle speed characteristic of the throttle valve, a voltage/frequency converter that obtains a reference pulse signal from the analog signal, and a motor of the DC motor. A phase comparator that compares the speed pulse signal with the reference pulse signal and generates an output pulse having a pulse width proportional to the phase difference between the two; 1. A constant speed traveling device comprising means for driving and controlling the DC motor so as to variably control the throttle opening speed in accordance with vehicle speed by pulse width modulation using waves. (2) When the speed deviation between the set vehicle speed and the actual vehicle speed is below a predetermined level, the means for controlling the drive of the DC motor disables variable control of the throttle opening speed in accordance with the vehicle speed, and changes the throttle opening speed vs. vehicle speed characteristic. The constant speed traveling device according to claim 1, characterized in that the control is switched to a constant speed.