JP3988468B2 - Cold speed correction method and correction device for vehicle speed control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle speed control device for driving a vehicle on a vehicle test device such as a chassis dynamometer, and more particularly to a correction method and a correction device at the time of cold start.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a speed control method for driving a vehicle on a chassis dynamometer, there is a speed control method with an acceleration minor as shown in FIG. 2 (Japanese Patent Publication No. 61-18433). In this method, a deviation signal between the vehicle speed command signal V _S and the vehicle speed detection signal V of the vehicle 4 is proportionally calculated by the speed controller 1 to obtain an acceleration command signal, and the vehicle speed detection signal V is differentiated by the differentiation calculator 5. An acceleration detection signal is obtained by calculation, and the deviation between the two acceleration signals is proportionally integrated by the acceleration calculator 2 to obtain an accelerator pedal stroke command θ _S, and further, an accelerator pedal stroke control signal θ is obtained by the stroke controller 3. To control the vehicle speed V so as to coincide with the vehicle speed command V _S. The symbols in the component blocks indicate the transfer function of each component.
[0003]
Since the conventional speed control with acceleration minor is feedback control, it is necessary to adjust the gain of the speed controller 1 and the like, and the transfer function MG (S) of the vehicle 4 has a large number of changing elements. Every time the change factor of the change, the gain adjustment of the speed controller 1 or the like is also necessary. Further, the feedback control loop is expressed as a closed loop transfer function, and there is a delay in control response determined by the gain of the speed controller 1 or the like.
[0004]
In order to improve these points, the present applicant has proposed a feedforward control method using an inverse function MG (S) ⁻¹ of the vehicle transfer function MG (S) (Japanese Patent Application No. 6-75532). As shown in FIG. 3, this control method uses an inverse function circuit 6 having an inverse function MG (S) ⁻¹ of a vehicle transfer function MG (S) as a transfer function, and sets the vehicle speed V to the vehicle speed command V _S. The accelerator pedal stroke θ _A necessary for matching is directly calculated, and this θ _A is output as an accelerator actuator operation signal θ _S. As a result, the accelerator actuator stroke θ = θ _A is set via the stroke controller 3, the accelerator pedal of the vehicle 4 is moved, and the vehicle speed V is matched with the vehicle speed command V _S.
[0005]
[Problems to be solved by the invention]
In the vehicle speed control device as described above, it is necessary to obtain data at the time of cold start of the vehicle, but if the vehicle is driven a little, the engine becomes hot and becomes a characteristic of the hot state. Then, since it did not return to the cold state, it was very difficult to obtain data at the cold start.
[0006]
The present invention has been made to solve the above-described problems, and is a vehicle speed control device that can obtain data on a hot state of a vehicle and also obtain data at a cold start of the vehicle. An object is to obtain a cold start correction method and correction device.
[0007]
[Means for Solving the Problems]
In the cold start correction method for a vehicle speed control device according to claim 1 of the present invention, the accelerator opening command is decreased at the cold start, and the decrease is reduced as the cooling water temperature increases or the accelerator opening command increases. Is.
[0008]
The cold start correction device of the vehicle speed control device according to claim 2 outputs an accelerator opening decrease output unit that outputs an accelerator opening decrease that decreases as the coolant temperature increases, and an accelerator opening command increase. The coefficient generator that generates a coefficient that decreases and approaches 1 and the output of the decrease output unit multiplied by the output of the coefficient generator calculate the decrease of the accelerator opening command, and this decrease is used as the accelerator opening command. Is provided with a calculation unit for subtracting from the calculation unit.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of a vehicle speed control apparatus according to this embodiment. The vehicle speed command V _S is input to the acceleration calculation unit 7 and the travel resistance unit 8, the acceleration calculation unit 7 outputs the acceleration command α _S , and the travel resistance unit 8 outputs the travel resistance F _RL . Multiplier 9 receives acceleration command α _S and multiplies vehicle weight W, and outputs acceleration force command F _{α S.} The acceleration force command F _{α S} and the running resistance F _RL are input to the adding unit 10 and added to output a driving force command F _RS . The multiplier 11 multiplies the driving force command _FRS by the tire radius r and outputs the axle shaft torque τ _as , and the division unit 12 multiplies the axle shaft torque τ _as by the transmission ratio i _M and the differential ratio i _D. Divide and output engine output torque τ _es . The reverse engine characteristic unit 13 receives the engine output torque τ _es and outputs an accelerator opening degree command θ _S ′ according to the inverse function relation of the engine characteristic. These constituent elements 7 to 13 constitute the inverse function circuit having the transfer function inverse function MG (S) ⁻¹ of the transfer function of the vehicle 4 shown in FIG.
[0010]
Reference numeral 14 denotes a decrease output unit that receives the engine coolant temperature T ° C. and outputs the accelerator opening decrease Δθ. The decrease Δθ is, for example, Δθ ₁ until the coolant temperature reaches 50 ° C. %), When the cooling water temperature exceeds 50 ° C., the temperature decreases linearly and reaches zero at 80 ° C. A coefficient generator 15 receives the accelerator opening command θ _S ′ and outputs a coefficient g. The coefficient g is constant g ₁ (> 1) until the opening command is θ ₁ (8%), for example. , Θ ₁ is linearly decreased, and when the opening degree command becomes θ ₂ (15%), it is set to 1.
[0011]
The multiplication unit 16 multiplies the output of the decrease output unit 14 and the output of the coefficient generation unit 15 to calculate a decrease Δθ _S ′ (which becomes a negative value) of the accelerator opening command θ _S ′. The adder 17 adds the accelerator opening command θ _S ′ and the decrease, and inputs it to the limiter 18 so that the added value does not become a negative value, thereby obtaining a new accelerator opening command θ _S. Therefore, when the output of the adder 17 is a negative value, the output of the limiter 18 becomes zero.
[0012]
Therefore, when the engine coolant temperature T ° C. is 50 ° C. or less and the accelerator opening command θ _S ′ is θ ₁ or less at the cold start, the decrease output unit 14 outputs Δθ corresponding to 2% of the total operation angle of the accelerator. ₁ is output, a coefficient g 1 greater than ₁ is output from the coefficient generator 15, and the multiplier 16 multiplies Δθ ₁ and g ₁ to reduce the accelerator opening command θ _S ′ by Δθ _S ′ (minus value). ) Is calculated, and θ _S ′ and the decrease Δθ _S ′ are added by the adding unit 17, and a new accelerator opening command θ _S is obtained via the limiter 18, and vehicle speed control is performed according to the θ _S. Is called. At the cold start, θ _S becomes smaller than θ _S ′, and the control at the normal cold start is performed, and the data at the cold start is obtained. When the cooling water temperature T ° C rises, the output Δθ of the decrease output unit 14 gradually approaches zero, and the output of the coefficient generation unit 15 gradually approaches 1 when the accelerator opening command θ _S 'increases. Therefore, when the engine is in a hot state, the output from the multiplication unit 16 becomes zero, and normal vehicle speed control is performed.
[0013]
The accelerator opening command θ _S is input to the opening control unit 19 and outputs an accelerator opening control signal θ. The control signal θ is input to the vehicle 4. In the vehicle 4, first, the engine characteristic unit 21 outputs an engine output torque τ _e corresponding to the control signal θ and the engine speed N _e , and the output torque τ _e is input to the multiplication unit 22 to obtain i _M × i _D. are multiplied is calculated the accelerator shaft torque tau _a, the shaft torque tau _a becomes the driving force F _R is divided by the tire radius r at the divider 23. The adder 24 subtracts the running resistance F _RL of the running resistor 25 from the driving force F _R to obtain the acceleration force F _α , the divider 26 divides by the vehicle weight W to obtain the acceleration α, and the integrator 27 The vehicle speed V is obtained by integrating the acceleration α.
[0014]
In the above embodiment, the speed control system is set to a characteristic corresponding to the hot state, and at the time of cold start, the decrease output unit 14, the coefficient generation unit 15, and the like decrease the accelerator opening command θ _S ′ by Δθ _S ′ Is calculated, and the accelerator opening command becomes small. Therefore, the control at the cold start is performed, and the control at the cold start is performed. When the coolant temperature of the engine rises, the decrease Δθ _S ′ becomes zero, the hot state is controlled, and hot state data is obtained.
[0015]
【The invention's effect】
As described above, according to the present invention, at the time of cold start, the accelerator opening command is decreased, and the decrease is made smaller as the engine coolant temperature increases or the accelerator opening command increases. Cold start control can be performed to obtain cold start data, and when a hot state occurs, the hot state control can be performed and hot state data can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram of a vehicle speed control device according to the present invention.
FIG. 2 is a block diagram of a conventional apparatus.
FIG. 3 is a block diagram of another conventional apparatus.
[Explanation of symbols]
4 ... Vehicle 14 ... Decrease output unit 15 ... Coefficient generation unit 16 ... Multiplication unit

Claims (2)

In the cold start correction method of the vehicle speed control device that controls the speed of the vehicle by controlling the accelerator opening, the accelerator opening command is decreased at the cold start, and this decrease is used to increase the cooling water temperature or the accelerator opening command. A cold start correction method for a vehicle speed control device, characterized in that the vehicle speed control device is made smaller in accordance with an increase in the vehicle speed. In a vehicle speed control device for controlling the accelerator opening to control the speed of the vehicle, an accelerator opening decrease output unit that outputs a decrease in the accelerator opening that decreases as the cooling water temperature increases, and an accelerator opening command The coefficient generator that generates a coefficient that decreases as the value increases and approaches 1 is calculated. The output of the output part of the decrease is multiplied by the output of the coefficient generator to calculate the decrease of the accelerator opening command. A cold start correction device for a vehicle speed control device, comprising a calculation unit for subtracting from a degree command.

Images