JPH10197409A - Method for controlling vehicle velocity of vehicle automatic-driving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle velocity control method whereby a change of a vehicle-driving force of a dynamo is detected and a vehicle velocity is controlled well to keep up with the change. SOLUTION: A difference of a vehicle-driving force F detected based on an actual speed Vact of a vehicle 1 and a vehicle-driving force Fads detected by a chassis dynamometer is obtained. A correction acceleration obtained from the difference ΔF of the driving forces and a vehicle weight is added to a target acceleration αnom obtained from a target vehicle velocity Vnom , thereby obtaining a feed forward acceleration αff . Moreover, the feed forward acceleration αff is added to an acceleration obtained by inputting a difference between the actual vehicle velocity Vact and the target vehicle velocity Vnom to a vehicle velocity control system 3, which is then input to a throttle degree estimation value generator 8 together with the target vehicle velocity Vnom .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle driving simulation in which a driving wheel is mounted on a rotating drum of a chassis dynamometer to drive a vehicle and a dynamic driving performance test of the vehicle is performed indoors. The present invention relates to a vehicle speed control method (hereinafter simply referred to as a vehicle speed control method) of an automatic vehicle driving device that automatically drives the vehicle.

[0002]

2. Description of the Related Art Conventionally, a chassis dynamometer (dynamo) has been used to simulate the actual running of a vehicle in order to test the dynamic running performance of an automobile. Air pressure or DC
A plurality of actuators are individually driven by a motor or the like, and an automatic vehicle driving device that allows a driver to depress an accelerator pedal, a brake pedal, a clutch pedal, and the like and to switch a shift lever has been used. I have.

[0003] In the actual driving simulation of the vehicle, it is necessary to drive the vehicle in a predetermined driving pattern. Therefore, the speed (vehicle speed) of the vehicle is required.
Need to be controlled. FIG. 2 shows a configuration of a conventional vehicle speed control device. In this figure, reference numeral 1 denotes a vehicle to be subjected to a test, which is mounted on a dynamo (not shown).

[0004] 2 the actual rotational speed of the target vehicle speed V _nom the vehicle 1 provided from the setting unit not shown (hereinafter, the actual vehicle speed hereinafter) is the difference point butt taking (vehicle speed deviation) V _err and V _act . _{Reference numeral} 3 denotes a vehicle speed control system, which includes a P term (P; gain) 4 and an I term (T; time constant) 5 for performing P control and I control of the vehicle speed deviation V _err , respectively. I have. _{Reference numeral} 6 denotes a differentiator for differentiating the target vehicle speed _Vnom .

7 is an output α _p of the P term 4 and an output α _{i of the} I term 5
(Both α _p and α _i are control outputs obtained by feedback control of the vehicle speed deviation V _err ) and the output α _nom of the differentiator 6 (this output is the rate of change of the target vehicle speed V _nom )
At each of these outputs α _p , α
_The sum of _i and α _nom is output as control acceleration α _ctl .

Reference numeral 8 denotes a throttle opening predicted value generator, which is an acceleration / throttle opening characteristic (hereinafter, referred to as a speed control) for controlling the speed of the vehicle 1.
8a), and a target vehicle speed V _nom and a control acceleration α _ctl from a matching point are input. Based on these inputs and the driving performance map 8a, target accelerations at various speeds are stored. Of the throttle opening (accelerator operation amount) A _act is output.

[0007] The running performance map 8a is obtained as follows. For example, when the vehicle automatic driving device learns the driving performance map, the relationship between the speed and the acceleration when a certain throttle opening is held is obtained at a plurality of points, and the relationship between the speed and the throttle opening output by the acceleration input is obtained. And memorize this. The driving performance map 8a is a manual transmission (M / T).
In the method, a database is created by obtaining the relationship between speed and acceleration when a certain throttle opening is held at several shift positions such as 1st and 2nd, and the like.

[0008] In the conventional vehicle speed control method,
Target acceleration α obtained by differentiating target vehicle speed V _nom
nom and a corrected acceleration (α _p + α _i ) obtained by inputting a difference V _err between the target speed V _nom and the actual vehicle speed V _act of the vehicle 2 to the speed control system 5 including the P term 3 and the I term 4 Sum (α
_nom + α _p + α _i ) as the control acceleration α _ctl , and inputs the control acceleration α _ctl and the target vehicle speed V _nom to the throttle opening predicted value generator 8, thereby obtaining the accelerator operation amount A _act and the vehicle 1 Had to control the speed.

The dynamo has a running resistance mode (ALR) and a constant torque control mode (ATR) as test modes. In the conventional vehicle speed control method, the learning of the running performance map 8a is performed by the ALR. Therefore, when the dynamo is ALR during actual traveling, the vehicle speed control can be favorably performed.

[0010]

However, in the case where the dynamo is an ATR, when the set torque value (vehicle driving force) suddenly changes, or when the dynamo is the ALR, the dynamo is in the middle of traveling. When the torque of the dynamo changes abruptly, such as when the amount of inertia changes abruptly, there is a problem that good speed following performance cannot be obtained and the speed falls outside the allowable range.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned circumstances, and has an object to detect a change in the vehicle driving force of a dynamo and to improve the vehicle speed control by following the change. The object of the present invention is to provide a vehicle speed control method capable of controlling the vehicle speed.

[0012]

In order to achieve the above object, according to the present invention, the relationship between the acceleration at each speed position of the automobile and the throttle opening is determined in advance, and the relationship between the acceleration and the throttle speed at the target speed is determined. In a vehicle automatic driving device in which a calculation result of a throttle opening predicted value generator for calculating a throttle opening predicted value of a throttle servo system to be controlled is input to a control target as an operation target value of a throttle servo system, Determine the difference between the vehicle driving force obtained based on the speed and the vehicle driving force obtained by the chassis dynamometer, and correct the acceleration obtained from the driving force deviation and the vehicle weight, and the target acceleration obtained from the target vehicle speed. The feedforward acceleration obtained by the addition is obtained, and further, the feedforward acceleration and the actual vehicle speed and the target vehicle speed are calculated. The added value of the acceleration obtained by inputting the vehicle speed control system, so that together with the target speed input to the throttle opening prediction value generator.

In the vehicle speed control method according to the present invention, a change in the vehicle driving force of the dynamo itself is detected by comparing the vehicle driving force obtained based on the actual speed of the vehicle with the vehicle driving force obtained by the dynamo. Calculating a corrected acceleration based on the vehicle driving force and the vehicle weight,
Since the feed forward acceleration and the added value of the acceleration obtained by inputting the difference between the actual vehicle speed and the target vehicle speed to the vehicle speed control system are input to the throttle opening predicted value generator together with the target vehicle speed, It is possible to perform control following changes in the vehicle driving force of the dynamo.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a vehicle speed control method according to the present invention. In this figure, the same components as those in FIG. 2 are the same.

In FIG. 1, reference numeral 9 denotes a vehicle driving force calculator.
The actual vehicle speed V _act of the vehicle 1 is input, and a vehicle driving force F _ads based on the actual speed V _act of the vehicle 1 is obtained based on the following equation (1). F _ads = A + BV + CV ² + I _ads · dV / dt−ML (v) (1) where A, B, and C are constants, ML (v) is the mechanical loss of the dynamo, and I _ads is the actual value of the vehicle 1. This is the amount of inertia.

_Reference numeral 10 denotes a vehicle driving force F _dyno from the dynamo and a vehicle driving force F obtained by the vehicle driving force calculator 9.
_The vehicle driving force F _dyno ,
The difference from F _ads (F _dyno −F _ads ) is output as ΔF. The F _dyno is given by the following equation (2). F _dyno = A + BV + CV ² + I _dyno · dV / dt−ML (v) (2) where I _dyno is the inertia of the dynamo.

The I _dyno has an accelerator opening of 8
When the state of 5% or more continues for 8 seconds or more, the accelerator opening degree changes without permission so as to be less than 85%. For this reason,
If this value cannot be used directly,
The dynamo inertia amount is obtained from the equation. I _dyno = I _ads ｛{F _dyno -RL (v) + ML (v)} / {F _ads -RL (v) + ML (v)} (3) where RL (v) is a running resistance. .

Reference numeral 11 denotes a feed forward (F / F) acceleration calculator to which the output α _nom of the differentiator 6, the output ΔF from the butting point, and the output A _{act of the} throttle opening predicted value generator 8 are input. Then, it is determined whether or not the ΔF is larger than the set value γ, and the corrected acceleration α _veh is obtained by the following equation (4). α _veh = (F _dyno −F _ads ) / (I _dyno −I _ads ) (4)

Next, a vehicle speed control method according to the above configuration will be described. (1) The vehicle driving force F _dyno is taken in from the dynamo.

(2) In the vehicle automatic driving device, that is, in the vehicle driving force calculator 9, the vehicle driving force F _ads based on the actual speed V _act of the vehicle 1 is obtained by using the equation (1).

(3) The vehicle driving force F _dyno and the vehicle driving force F _ads are abutted at the abutting point 10, and the difference ΔF is obtained.

(4) The ΔF is an F / F acceleration calculator 1
1 and is compared with a preset value γ (this value γ is variable). When ΔF ≧ γ, it is determined that the vehicle driving force F _dyno of the dynamo has changed abruptly. . Further, when ΔF <γ, it is _determined that there is no rapid change in the vehicle driving force F _dyno of the dynamo, so that F _dyno = 0.

(5) In the F / F acceleration calculator 11, a corrected acceleration α _veh is _obtained by using ΔF and the equations (2) to (4).

(6) Further, the F / F acceleration calculator 1
1, the target acceleration α obtained from the target vehicle speed V _nom
nom and the corrected acceleration α _veh are added, and this is
An F acceleration α _ff is output to the butting point 7.

(7) The actual vehicle speed V
Since _act and the target vehicle speed V _nom the difference in a vehicle speed deviation V _err acceleration obtained by inputting the vehicle speed control system 3 (α _p + α _i) is input, the acceleration (α _p + α _i) and the The F / F acceleration α _ff from the F / F acceleration calculator 11 is added, and the addition result (α _p + α _i + α _ff ) is input to the throttle opening predicted value generator 8 as the control acceleration α _ctl .

(8) The throttle opening predicted value generator 8
, A target vehicle speed V _nom is input, and by applying the target vehicle speed V _nom and the control acceleration α _ctl to the traveling performance map 8, an accelerator operation amount A _act is obtained. Is operated.

In the vehicle speed control method in the above embodiment, the vehicle driving force F _ads obtained based on the actual vehicle speed V _act of the vehicle 1 and the vehicle driving force F _dyno obtained by the dynamo are _used.
By comparing Dynamo's own vehicle driving force F
A change in _dyno is detected, and the driving forces F _dyno and F _{ads of the} two vehicles are detected
The corrected acceleration α _veh is obtained based on the vehicle speed and the target acceleration α _nom obtained from the target vehicle speed V _nom to obtain an F / F acceleration α _ff obtained by adding the corrected acceleration α _veh. Acceleration α _ff , actual vehicle speed V _act and target vehicle speed V _nom
The value (α _p + α _i +) obtained by adding the difference V _err to the acceleration (α _p + α _i ) obtained by inputting the difference V _err to the vehicle speed control system 3
α _ff ) is input to the throttle opening predicted value generator 8 together with the target vehicle speed V _nom , so that when the dynamo's vehicle driving force changes, control following the change can be performed.

By the way, in the US06 mode (one of the US test standards), when the state where the accelerator opening is 85% or more continues for 8 seconds or more, there is a first method of changing the amount of inertia. Since the accelerator operation amount A _act is input to the F / F acceleration calculator 11, it can be used for determining whether or not to obtain the corrected acceleration α _veh, and the inertia amount of the dynamo in the US06 mode There is an advantage that good control can be performed even if the value changes.

The present invention is not limited to the above-described embodiment. For example, the vehicle speed control system 3 may be configured as a feedback control system other than the P and I controls. Further, the change ΔF in the vehicle driving force may be directly taken in from the dynamo.

[0030]

The present invention is embodied in the above-described embodiment and has the following effects.

It is possible to detect a change in the vehicle driving force of the dynamo, to perform a control satisfactorily corresponding to the change in the vehicle driving force, and to perform a good vehicle speed following control.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration for implementing a vehicle speed control method of the present invention.

FIG. 2 is a diagram showing a configuration for implementing a conventional vehicle speed control method.

[Explanation of symbols]

1 ... vehicle, 3 ... vehicle speed control system, 8 ... throttle opening predicted value generator, _Vnom ... target vehicle speed, _Vact ... actual vehicle speed, _Verr ...
Vehicle speed deviation, F _ads : Vehicle driving force obtained based on actual vehicle speed, F _dyno : Vehicle driving force obtained by chassis dynamometer, ΔF: Drive force deviation, α _nom : Target acceleration, α
_ff : feed forward acceleration, α _p , α _i : output of the vehicle speed control system.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01M 17/00 A

Claims (1)

[Claims] 1. A throttle for calculating a predicted throttle opening degree of a throttle servo system which is required in accordance with a speed change rate at a target speed in advance, in which a relationship between an acceleration at each speed position of an automobile and a throttle opening degree is obtained in advance. In a vehicle automatic driving device in which the calculation result of the opening degree predicted value generator is input to a control target as an operation target value of a throttle servo system, a vehicle driving force obtained based on the actual speed of the vehicle and a chassis dynamometer are used. And a corrected forward acceleration obtained from the driving force deviation and the vehicle weight, and a target acceleration obtained from the target vehicle speed, to obtain a feedforward acceleration obtained. The sum of the forward acceleration and the acceleration obtained by inputting the difference between the actual vehicle speed and the target vehicle speed to the vehicle speed control system A vehicle speed control method for an automatic vehicle driving apparatus, wherein the vehicle speed is input to the throttle opening predicted value generator together with a target speed.