JP3127547B2 - Chassis dynamometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chassis dynamometer for controlling an engine output by detecting a tire wheel shaft torque.

[0002]

2. Description of the Related Art In a chassis dynamometer for performing a road running simulation test, a driving wheel tire of a test vehicle is mounted on a chassis roller, and an electric motor as a power absorber is directly connected to the chassis roller or connected via a gear. A drive robot that operates an accelerator, a clutch, and the like of an automobile with an actuator is provided, and various tests simulating running on a road are performed.

[0003] When the test vehicle is independent of each wheel or front and rear wheels such as a 4WD vehicle, the chassis dynamometer controls the engine output by detecting the tire wheel torque.

FIG. 2 shows a torque control system in a conventional chassis dynamometer. The drive wheel tire 2 of the test vehicle 1 is mounted on a chassis roller 3, and a dynamometer 4 including an electric motor, a speed-increasing gear, and a control device thereof is connected to the chassis roller 3. A tire wheel torque meter 5 is connected to the tire 2, and the output of the torque meter 5 is extracted as a torque detection signal by a strain amplifier 6.

[0005] Automatic operation of the accelerator of the test vehicle 1 is performed by operating an accelerator pedal 8 by an electric accelerator actuator 7. The accelerator actuator 7 is controlled by a torque control amplifier 10 in which a set value T _S of a tire wheel torque setting device 9 and a torque detection value from a strain amplifier 6 are compared, and an output of the torque control amplifier 10 is set as an accelerator opening command θ _S. tire wheel and accelerator opening control amplifier 11 by abutting the stroke (accelerator opening) detection signal, which includes a chopper unit 12 for controlling the electric motor rotation amount of actuator 7 in accordance with the output corresponds to the torque set value T _S of The accelerator pedal 8 is operated so as to obtain a torque.

[0006]

In the conventional torque control system, a power transmission system (transmission, differential gear, propeller shaft, and accelerator shaft) is included in a torque detection signal from a torque meter provided on a tire wheel.
Since the backlash and torsional vibration components are included, the responsiveness of the torque control cannot be increased, which affects the test accuracy of a rapid acceleration test or the like.

The relationship between the stroke of the accelerator pedal 8 and the opening of the throttle lever of the engine has a non-linear characteristic in order to improve the engine response to the accelerator depression amount (stroke). In addition to the non-linear characteristics, the control error of the accelerator transmission system from the actuator 7 to the engine appears as an error of the torque control system due to play of the accelerator pedal mechanism, play, and the like.

[0008] The actuator has the following problem.

(A) The backlash and loss of the motor and gear of the actuator 7 are relatively large, and the link mechanism is bent. (B) Since the chopper unit is a pulse frequency modulation system, the control response near zero crossing is reduced. (C) the control resolution cannot be increased due to the combination of the above (a) and (b); and (d) the control response is not linear because the DC servo using a motor as a DC motor does not have linear characteristics. Cannot be raised.

[0010] An object of the present invention is to provide a chassis dynamometer that achieves high responsiveness and high accuracy in torque control by detecting shaft torque.

[0011]

SUMMARY OF THE INVENTION The present invention provides a solution to the above problems.
In order to make a decision,tireThe chassis roller on
And a dynamometer coupled to the chassis roller
Power absorption, torque set value and automobile tire wheel
Chassis that controls engine output by detecting shaft torque
-In the dynamometer,E attached to the tire
Tire shaft torque detection value detected by Eel torque meter
And the torque set valueTorque command by proportionally integrating the deviation
And a correction amplifier to obtainSaid detected by load cell
Absorption torque T of dynamometer and chassis roller
_A And the mechanism of these dynamometers and chassis rollers
Acceleration / deceleration torque T due to inertia _D And mechanical loss M _L
And multiply the result by the tire radius.tire
A torque detection circuit that detects the wheel axle torque;
Torque command from the correction amplifier and the torque detection circuitOr
Tire wheel shaft torque detection signalFrom the engine
And torque control means for performing torque control.
And

[0012]

[Function] A torque control system based on a shaft torque obtained by calculation from the absorption torque of a dynamometer is provided in a minor loop of the tire wheel shaft torque control, and a high response to the tire wheel shaft torque control is obtained. Eliminate stationary errors.

[0013]

FIG. 1 is a configuration diagram of a torque control system showing an embodiment of the present invention. 2, the same components as those in FIG. 2 are denoted by the same reference numerals. The DC dynamometer 4 to be a DC motor is directly connected to the chassis roller 3 in a gearless system without a gearbox.
Further, a load cell 21 is provided, and an absorption torque T _{A of the} dynamometer 4 is extracted as an output of the strain amplifier 22.

[0014] The adder 23 obtains the absorption torque with respect to the tire 2 by adding the acceleration and deceleration torque T _D and the mechanical loss M _L absorption torque T _A. Deceleration torque T _D is the inertia component GD ² and the acceleration dN with a mechanism from the tire 2 to dynamometer 4
It is obtained by calculation from / dt. Mechanical loss M _L is measured in advance as a mechanical loss such as a gear, with the said mechanism (mechanical loss).

The multiplier 24 multiplies the output of the adder 23 by the set value of the tire diameter setter 25 for setting the radius of the tire 2 to obtain the absorption torque converted into the axial torque of the tire 2. This absorption torque is converted into a feedback signal of a torque control amplifier 26, and a torque command to the amplifier 26 is given through a correction amplifier 27.

The correction amplifier 27 obtains a value obtained by proportionally integrating the deviation between the torque set value T _S of the torque setting device 9 and the shaft torque detection signal from the torque meter 5 through the strain amplifier 6 and the low-pass filter 28. The correction amplifier 27 corrects an error between the torque set value T _S and the shaft torque detection signal. The low-pass filter 28 removes a drive torque variation (AC component) included in the torque detected by the torque meter 5 to obtain a DC component (average torque) of the shaft torque.

Next, instead of the conventional accelerator control, the engine control of the test vehicle 1 is performed by direct control of the throttle and with linearity. The electric throttle actuator 29 for this operates the throttle lever of the engine in the automobile 1 via the throttle wire 30,
This operation amount (stroke) is extracted by the stroke detector 31 as a throttle opening degree detection signal. Also,
The torsion spring of the actuator 29 uses a linear type.

The throttle opening control amplifier 32 uses the output of the torque control amplifier 26 as a throttle opening command, and obtains a control signal for the throttle actuator 29 from the throttle opening detection signal of the stroke detector 31. The control signal is converted and amplified into a pulse width signal by a pulse width modulation type servo driver 33, and the rotation amount of the electric motor of the throttle actuator is controlled according to the pulse width.

In this embodiment, the torque control of the test vehicle 1 is performed by calculating the shaft torque from the absorption torque of the dynamometer 4 and the like, and the torque control amplifier 26 performs the shaft torque control according to the torque command. This torque control system enhances the responsiveness of the torque control irrespective of backlash or backlash of the power transmission system of the test vehicle 1, and the engine output can be changed even when the torque setting device 9 changes abruptly (such as sudden acceleration). Get a fast response to torque.

Here, since a steady error occurs in the detection and control of the shaft torque from the dynamometer side, this error is corrected by the correction amplifier 27 according to the detection signal of the shaft torque meter 5. This correction enables accurate torque control by removing the AC component by interposing the low-pass filter 28, and secures torque control accuracy even in an operation state where the engine speed is low.

Next, in this embodiment, since the engine output control is performed by direct operation of the throttle opening and has linearity, it is possible to obtain a high-speed response and linear shape in the stroke and throttle opening characteristics. Compared to the operation of the accelerator pedal, control with high accuracy can be achieved by eliminating error factors such as play and play of the pedal mechanism, and control that contributes to ensuring high responsiveness and accuracy of the torque control system can be obtained.

In this embodiment, a pulse width modulation type servo driver 33 is used for controlling the throttle actuator 29.
Therefore, even during low-speed operation of the engine, the number of pulses is constant and stroke control is performed by changing the width, and control responsiveness and accuracy can be secured from low-speed operation to high-speed operation,
Throttle control that contributes to ensuring high responsiveness and accuracy of the torque control system.

Further, in this embodiment, since the chassis roller 3 is directly connected to the dynamometer 4 without gears, the intervention of the conventional gearbox or the like adversely affects the responsiveness and accuracy of torque control due to backlash and backlash. Can be eliminated.

[0024]

As described above, according to the present invention, as a minor loop of the tire wheel shaft torque control, a torque control system based on the shaft torque calculated by the absorption torque of the dynamometer is provided, and the torque set value and the torque meter are provided. Since the deviation from the detected value is corrected by the correction amplifier for the torque command, the torque control system of the minor loop can be used for high-speed response shaft torque control and the torque accuracy of the correction amplifier can be ensured.

Also, the throttle actuator of the engine has a direct and linear throttle actuator and the stroke of the actuator is controlled by a pulse width modulation method. By providing a low-pass filter for removing the torque, it is possible to ensure the responsiveness of the torque control system and the accuracy.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a torque control system showing one embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional torque control system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Test vehicle, 3 ... Chassis roller, 4 ... Dynamometer, 5 ... Tire wheel torque meter, 6 ... Strain amplifier, 9 ... Torque setting device, 21 ... Load cell, 22
... Strain amplifier, 23 ... Adder, 24 ... Multiplier, 2
5: Tire diameter setting device, 26: Torque control amplifier, 27:
Correction amplifier, 28: Low-pass filter, 29: Throttle actuator, 32: Throttle opening control amplifier, 3
3. Servo driver.

Continuation of the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 17/00-17/10 F02D 45/00 364 G05D 17/02 G01L 3/22 JICST file (JOIS)

Claims (5)

(57) [Claims] 1. A chassis in which a tire of a test vehicle is mounted on a chassis roller, power is absorbed by a dynamometer connected to the chassis roller, and an engine output is controlled by detecting a torque set value and a tire wheel axle torque of the vehicle. In the dynamometer, it is detected by the wheel torque meter attached to the tire.
Amplifier for obtaining a torque command by proportionally integrating a deviation between a detected value of a shaft torque of the tire and the set value of the torque, a dynamometer and a dynamometer which are detected by a load cell.
The absorption torque T _A of the chassis roller and the dynamometer
Acceleration and deceleration due to the inertia of the motor and chassis roller mechanisms
The sum of the torque T _D and the mechanical loss M _L, the sum
A torque detection circuit that detects a tire wheel axle torque by multiplying by a tire radius, a torque command from the correction amplifier, and the torque detection circuit
And a torque control means for controlling the torque of the engine based on the tire wheel shaft torque detection signal from the chassis dynamometer. Wherein said torque control means to claim 1, further comprising a throttle actuator to operate with linearity directly and the throttle lever of the engine
The chassis dynamometer described . 3. A process according to claim 1 or 2, wherein the torque control means comprising the servo driver for controlling the stroke of the throttle actuator in a pulse width modulation
The chassis dynamometer according to 1. 4. The vehicle according to claim 1, wherein the chassis roller and the dynamometer have a direct connection structure.
The chassis dynamometer according to claim 1 or 2 . 5. The chassis dynamometer according to claim 1, further comprising a low-pass filter that removes a driving torque fluctuation for detecting the tire torque.