JP2803309B2 - Throttle control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throttle control device that controls opening and closing of a throttle valve without using a mechanical link for accelerator operation.

(Prior Art) Conventionally, as a throttle control device, for example,
What is described in JP-A-60-164629 is known.

According to this conventional source, an output signal of an accelerator operation amount is supplied to a low-pass filter or the like that removes an inappropriate frequency component that causes vehicle vibration, and based on the result, a valve opening of a throttle valve is controlled, and a drive shaft is controlled. There is disclosed an apparatus for preventing the occurrence of vehicle vibration by reducing the torque fluctuation of the vehicle.

(Problems to be Solved by the Invention) However, in such a conventional throttle control device, the cut-off frequency ω of the low-pass filter is used to reduce the drive shaft torque fluctuation that causes the vehicle vibration.
_{n (g)} the order must be even lower than the natural frequency omega _P of the vehicle vibration frequency, the throttle valve operation becomes sluggish relative to the accelerator operation input, the rise of the driving torque is delayed, acceleration feeling of the vehicle with respect to the accelerator operation Is impaired, and the running feeling is not favorable.

That is, when the low-pass filter is used, if the drive shaft torque attenuation (convergence) is improved, the drive shaft torque responsiveness (rapid response) to the accelerator operation is deteriorated.

Therefore, the present applicant has applied a model following control method,
Transmission characteristics with good drive shaft torque damping and high drive shaft torque response to accelerator input (reference model)
, And a device that controls the throttle so that the actual driving torque follows the response of the reference model was proposed earlier.

In the case of the throttle control based on the model follow-up, as shown in FIG. 10, it is possible to make the change in the longitudinal behavior of the vehicle accompanying the accelerator OFF operation gentler than in the case where the throttle control is not performed as shown in FIG. it can.

However, in the case of model following control or low-pass filter control that reduces drive shaft torque fluctuation, if the vehicle enters the corner at overspeed and attempts to change the direction of the vehicle using the tack-in phenomenon caused by the accelerator OFF operation, FIG. As shown by the solid line trajectory, the direction of the vehicle does not change sufficiently against the driver's expectation, and the trajectory of the vehicle expands outside the course.

This is because in the throttle control that reduces the drive shaft torque fluctuation, the load movement in the front-rear direction and the change in the front-rear force of the driving wheel at the contact point become gradual. This is due to reduction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem. In a throttle control device that performs opening / closing control of a throttle valve without using a mechanical link for accelerator operation, a drive shaft torque during a normal accelerator operation is provided. It is an object of the present invention to obtain a vehicle turning performance expected by a driver during a tack-in operation while achieving a damping property.

(Means for Solving the Problems) In order to solve the above problems, the throttle control device of the present invention temporarily controls the throttle control for reducing the torque fluctuation of the drive shaft during a tack-in operation in which the accelerator is turned off during high lateral acceleration turning. To perform control corresponding to the accelerator opening.

That is, as shown in handling claims diagram of Figure 1, inputs the accelerator opening detection unit a for detecting the accelerator opening theta _A operated by a driver, a signal from the accelerator opening detection unit a, and the throttle valve opening degree target value decision unit b for determining a throttle valve opening degree target value _{T 'to} reduce the torque fluctuation of the drive shaft, and the lateral acceleration corresponding physical quantity detection unit c for detecting a lateral acceleration corresponding physical quantity Y _G of the vehicle, Tack-in operation determining means d for inputting signals from the accelerator opening detecting section a and the lateral acceleration equivalent physical quantity detecting section c to determine whether or not the accelerator is released during high lateral acceleration turning, and a throttle during normal accelerator operation. Valve opening target value determination unit b
From the throttle valve opening target value _T ′ to the throttle valve opening final target value _T, and at the time of accelerator release operation during high lateral acceleration turning, the accelerator opening θ _A is kept unchanged for a predetermined time. A switching means e for switching to a valve opening final target value _T side, and a control signal i to a throttle actuator f so that the actual throttle valve opening θ _T coincides with the throttle valve opening final target value _T. And a throttle actuator control unit g.

(Operation) At the time of traveling accompanied by an accelerator operation, the tack-in operation determining means d uses the accelerator opening θ _A from the accelerator opening detecting section a and the lateral acceleration equivalent physical quantity Y _G from the lateral acceleration equivalent physical quantity detecting section c. Based on these two pieces of information, it is determined whether or not an accelerator release operation in a high lateral acceleration turn.

During the normal accelerator operation, the switching means e selects the throttle valve opening target value _T 'from the throttle valve opening target value determining section b as the final target value _T of the throttle valve opening, and the high lateral acceleration rotation is performed. when the accelerator release operation in a predetermined period of time, switched the accelerator opening theta _a on the side with the throttle valve opening final target value _T as it is in the throttle actuator control unit g, the throttle valve opening final target value _T control signal i to the throttle actuator f so that the actual throttle valve opening theta _T matches is output.

Therefore, at the time of accelerator operation other than at the time of tack-in operation, throttle valve control to reduce torque fluctuation of the drive shaft is performed.For example, at the time of sudden accelerator ON operation, due to good drive shaft torque damping for accelerator input, The vibration of the vehicle is prevented, and when the accelerator is turned off during straight running, the change in behavior in the front-rear direction associated with the accelerator operation becomes gentle.

Further, at the time of tuck operation, will be the control of accelerator opening corresponding to the accelerator opening theta _A target value is performed, the vehicle once fogging matching expectations driver is obtained by tuck phenomenon.

(Example) Next, an Example is described based on drawing.

 First, the configuration will be described.

FIG. 2 is an overall block diagram showing a throttle control device of the embodiment, wherein 1 is an accelerator pedal operated by a driver,
2 accelerator opening sensor for detecting an accelerator opening theta _A is a depression amount of the accelerator pedal 1, 3 is an A / D converter,
The gear position sensor for detecting a gear position P _G of the transmission 4, 5
An engine speed sensor for detecting an engine speed N _E is
Interface circuit for inputting a signal of the gear position P _G and the engine speed N _E is 6, 7 throttle controller for outputting a motor current target value to input signals from the sensors, the motor of the motor drive circuit 8 driver,
9 is a servomotor as a throttle actuator,
Reference numeral 10 denotes a throttle valve controlled to be opened and closed by a servomotor 9, reference numeral 11 denotes a throttle opening sensor for detecting an actual throttle opening θ _T of the throttle valve 10 based on a motor rotational position, reference numeral 12 denotes an A / D converter, and reference numeral 13 denotes a lateral acceleration Y. A lateral acceleration sensor 14 for detecting _G is an A / D converter.

Then, the throttle controller 7, a good drive shaft torque damping property to the accelerator opening theta _A is an accelerator input, and sets the drive shaft torque response of high transmission characteristic (reference model), pre A throttle opening target value calculation unit that calculates a throttle opening target value _T ′ so that the actual drive torque follows the response of the reference model by compensation.
7a and, a turning determination section 7b to determine whether the time of high lateral acceleration turning based on the detected value of the lateral acceleration Y _G, to change the state of the high lateral acceleration turning signal and the accelerator opening theta _A from the turning decision unit 7b A control stop determining unit 7c that determines the stop of the throttle control by following the model when determining the tack-in operation based on the tack-in operation,
A switching unit 7d for switching whether to use the accelerator opening theta _A or using the throttle opening target value _{T 'as T,} the motor based on a deviation [Delta] [theta] _T between the throttle opening final target value _T and the actual throttle opening theta _T A motor current target value determination unit 7e for determining a current target value.

Each of the parts 7a to 7e of the throttle controller 7 is configured as a microcomputer program.

 Next, the operation will be described.

FIG. 3 is a flowchart showing the flow of the throttle control processing operation performed by the throttle controller 7, and each step will be described below.

In step 30, when power is supplied to the throttle controller 7, a power-on routine is started, and initialization processing for initializing the microcomputer and initial values of variables necessary for calculation are performed.

In step 31, when the ignition key is turned on, a background program (BGJ) is executed, and an interrupt for performing a main operation is permitted. In the BGJ routine, a control that does not require much urgency or a control constant calculation is performed.

For example, in this embodiment, the program is a program for checking the level of the power supply voltage, and the natural frequency ω _{P (g)} and the deceleration coefficient ζ
Determination of _{P (e)} can also be performed.

Steps 32 to 39 are a main calculation and control flow of the operation amount of the throttle valve 10, and are executed by a timer interruption every Δt seconds.

In step 32, a detection signal is read from each sensor.

In step 33, the throttle opening target value _T 'is calculated by the following equation. _{T '= W (S) ·} θ A ... (1) where, W (S) is a predistorter for a drive torque T _D of the vehicle to match the drive torque T _DM of the target vehicle at the time of accelerator operation is there.

In step 34, the lateral acceleration Y _G is set to a predetermined value (for example, 0.5
Whether high lateral acceleration turning state is judged by whether or G) above, in step 35, the accelerator opening theta _A whether when the accelerator OFF is judged by whether or fully closed.

In the determination in the above steps 34 and 35, Y _G
When the condition of ≧ predetermined value and θ _A = fully closed is not satisfied, that is, when the accelerator is operated other than the operation for generating so-called tack-in, the process proceeds to step 36, and the throttle opening target value _T ′ is set to the throttle opening. It is set as the final target value _T.

When the condition of Y _G ≧ predetermined value and θ _A = fully closed condition is satisfied, that is, at the time of tack-in operation for generating so-called tack-in, the process proceeds to step 37, and the accelerator opening θ _A is directly changed to the throttle opening final target value. Set as _T.

In step 38, the throttle opening final target value _T
And taking the difference [Delta] [theta] _T between the actual throttle opening theta _T, determines a target current value to the deviation [Delta] [theta] _T to zero by using a transfer function G (S).

The transfer function G (S) acts as a P, PI or PID controller (P; proportional control operation, I; integral control operation, D; differential control operation).

In step 39, the current target value is output to the motor driver 8.

The current target value may be output by D / A conversion or PWM.
The control output may be a pulse output.

Next, the predistorter W (S) for realizing model following (model following) in the throttle control device of the embodiment will be described.

First, the pre-compensator W (S) cancels the inherent transfer characteristics of the own vehicle and attains the desired transfer characteristics (reference model).
When the overall control system including the own vehicle is viewed, an output that follows the reference model with respect to the input is obtained by connecting the pre-compensator W (S) in series before the own vehicle. Model following will be realized.

That is, the front compensator W (S) calculates the natural frequency ω of the host vehicle.
_P and the deceleration coefficient 逆 The inverse system of the inherent transmission characteristic _GP of the own vehicle between the throttle opening input and the drive shaft torque output modeled using _P , the natural frequency ω _m and the damping coefficient 目標 of the target vehicle accelerator opening input target vehicle modeled using _m - drive shaft torque based on the desired transfer characteristic G _M between the output set by the accelerator opening input - which satisfies the transmission characteristic between the throttle valve opening output It is.

Here, the natural frequency ω _m and the damping coefficient ζ _m of the target vehicle
The accelerator pedal and the throttle valve and mechanically to an accelerator input than in the case of proportional control by linking to keep good driving shaft torque damping and the drive shaft torque response and natural frequency of the vehicle omega _P and it is arbitrarily set in relation ω _P ≦ ω _m and ζ _{p <ζ m} relative damping factor zeta _P.

Further, specific transfer characteristic G _P with the own vehicle is modeled using the natural frequency omega _P and a damping coefficient zeta _P of the vehicle, the natural frequency changes by a change in gear position P _G omega _P and the damping coefficient zeta _P which changes by a change in the engine speed N _E, the attenuation coefficient of the natural frequency ω _{P (g)} and the engine speed corresponding gear ratio corresponding by state feedback varying in response to these conditions change ζ Determined as _{P (e)} to achieve optimal model following in all vehicle conditions.

Hereinafter, specifically speaking, in a general vehicle,
When the throttle opening input θ (S) is given, the input / output transfer characteristic G _P (S) of the drive shaft torque T _D (S) generated on the drive shaft (drive shaft) is approximately the following according to the experimental results. It can be expressed as follows.

Here, h ^* is a static characteristic, e- ^LS is a ^dead time, and S is a Laplace operator.

 Here, the above equation (2) is rewritten as follows.

However, On the other hand, the input / output transfer characteristic G _M (S) of the target vehicle for obtaining a desired drive shaft torque T _DM (S) when the throttle opening input θ (S) is given is given by the above equation (2-1). In the corresponding form, , L _M ≧ L _P L _M ; G _M ′ (S) order difference of the numerator and denominator L _P ; G _P The order difference between the numerator and denominator of '(S) is generally known.

Therefore, in the present embodiment, assuming that L _M = L _P , G _M ′ (S) in the equation (2-2) is expressed as follows: And give a normative model as follows:

Then, the pre-compensator W (S) for satisfying T _D = T _DM at the time of accelerator operation according to the above equations (2) and (3).
Is given by the following equation.

In the above equation (4), when ωP _(g) = ωm _(g) , the following equation is obtained.

Where a ₀ = ω _{m (g)} ² b ₀ = ω _{P (g)} ² a ₁ = 2ζ _{m (e)} ω _{m (g)} b ₁ = 2ζ _{P (e)} ω _{P (g)} 5) input u (S) corresponds to the accelerator opening theta _a in formula, the output y (S) is the throttle opening target value
_T ′, the expression (Step 33)
_T ′ = W (S) · θ _A ) is obtained.

That is, the natural frequency ω _{P (g)} (= ω _{m (g)} ) and the damping coefficient ζ
_{P (e)} and ζ _{m (e)} are determined, and the constants a ₀ ,
If the values of b ₀ , a ₁ , b ₁ are obtained by calculation, the pre-compensator W (S)
Are obtained, and these natural frequencies ω _{P (g)} (=
ω _{m (g)} ) and the damping coefficients ζ _{P (e)} and ζ _{m (e)} may be given as fixed values as average values. For example, the natural frequency ω
_{P (g)} was determined based on the natural frequency map shown in FIG. 4 created based on the experimental results, and the damping coefficient ζ _{P (e)} was also created based on the experimental results that obtained the optimal damping properties. In the case where it is determined by the attenuation coefficient map shown in FIG. 5,
Change the influence of the damping coefficient of the vehicle due to the vehicle of the natural frequency of the changes affect the engine speed N _E changes Shi is eliminated by the gear position change is eliminated, gear position change between the engine speed N _E only independent In the whole range, the desired control effect by the model following that achieves both the drive shaft torque attenuation and the drive shaft torque response to the accelerator input can be obtained.

As described above, in the throttle control device of the embodiment, the following effects can be obtained.

At the time of accelerator operation other than the tuck-in operation, a transmission characteristic (reference model) having a good drive shaft torque damping property and a high drive shaft torque response to the accelerator input is set.
The system performs model following throttle control in which the actual drive torque follows the reference model response, temporarily stops model following throttle control during tack-in operation, and performs proportional throttle control corresponding to the accelerator opening. While achieving both the drive shaft torque damping property and the drive shaft torque responsiveness during other accelerator operations, the required tack-in phenomenon occurs during the tack-in operation, and the vehicle turns as expected with the vehicle turning performance that matches the driver's expectations. Direction can be changed.

As a result, for example, when the accelerator is suddenly turned ON, the vehicle vibration is prevented by the favorable drive shaft torque attenuating property with respect to the accelerator input, and the rising response of the drive shaft torque to the accelerator operation is also ensured.

In addition, when the accelerator is turned off in straight running, as shown in FIG. 10, the behavior change in the front-rear direction due to the engine brake is moderated while the engine brake is applied.

Moreover, it entered at overspeed the corner, the accelerator OFF at the time of tuck operation to try to change the orientation of the vehicle by utilizing the tack-in phenomenon due to the operation, an accelerator opening degree corresponding proportional throttle control to the accelerator opening theta _A target value Is performed, as shown by the dotted trajectory in FIG. 6, the direction of the vehicle is sufficiently changed in accordance with the driver's expectation, and the trajectory of the vehicle is prevented from expanding to the outside of the course. .

This is because, by temporarily stopping the throttle control for reducing the drive shaft torque fluctuation, the load movement in the front-rear direction and the change in the front-rear force of the driving wheel at the contact point are not reduced.
This is because when the accelerator is turned off during turning, the vehicle turns easily due to the tack-in phenomenon.

As described above, the embodiments have been described based on the drawings. However, the specific configuration is not limited to the embodiments, and even if there is a design change or the like without departing from the gist of the present invention, it is included in the present invention. .

For example, in the embodiment, as an example of the throttle control for reducing the drive shaft torque, an example of a preferable model following control capable of achieving both the drive shaft torque attenuation and the drive shaft torque responsiveness to the accelerator input has been described. In other words, the control includes, for example, a control using a low-pass filter as described in the related art, that is, a control in which the effectiveness of the engine brake is reduced at the time of an accelerator OFF operation with a small accelerator operation amount in order to aim at the drive shaft torque attenuation.

In the model following control of the embodiment, the natural frequency is set to ω
And _{P = ω m,} although an example in which the damping coefficient ζ _{p <ζ m,} can be arbitrarily set if satisfying the relation ω _P ≦ ω _m and ζ _{p <ζ m, ω P} <it is possible to rise characteristics of the drive shaft torque (response) to further improve the extent permitted by the performance of the throttle actuator by setting the omega _m. When ω _P = ω _m is set,
The drive shaft torque response to a throttle input is similar to that of a normal vehicle in which an accelerator pedal and a throttle valve are mechanically linked.

Further, in the embodiment, a gear position sensor is shown as an example of the state detecting means for changing the natural frequency, and the gear position is used as the state information. However, the gear ratio calculated by the vehicle speed and the engine speed may be used as the state information. good.

Further, in the embodiment, the example of the engine speed sensor is shown as the state detecting means for changing the damping coefficient, and the example in which the engine speed is used as the state information is shown. However, the vehicle speed may be used as the state information.

Further, in the embodiment, an example is shown in which a lateral acceleration sensor is used as the lateral acceleration equivalent physical quantity detection unit. Instead of this lateral acceleration sensor, as shown in FIG. 7, a yaw rate sensor 15 and a vehicle speed sensor 16 are used. The lateral acceleration calculator 17 may be used.

In this case, computing the lateral acceleration Y _G by the following equation in the lateral acceleration calculation section 17.

Y _G = V In place of the lateral acceleration sensor, a steering angle sensor 18, a vehicle speed sensor 19, and a lateral acceleration estimation calculation unit 20 may be used as shown in FIG.

In this case, computing the lateral acceleration estimated value Y _G by the lateral acceleration estimation calculating unit 20 in the following equation.

Here, A is a vehicle-specific stability factor, N is a steering gear ratio, and L is a wheelbase.

(Effects of the Invention) As described above, according to the present invention, in a throttle control device that performs opening / closing control of a throttle valve without relying on a mechanical link for an accelerator operation, the accelerator is turned off at high lateral acceleration turning. During the tuck-in operation, the throttle control to reduce the torque fluctuation of the drive shaft is temporarily stopped, and the means to perform control corresponding to the accelerator opening is used. In the tuck-in operation, the turning trajectory as intended can be obtained by the turning performance of the vehicle as expected by the driver while achieving the vehicle behavior of the vehicle.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram showing a throttle control device of the present invention, FIG. 2 is a control system block diagram showing a throttle control device of an embodiment, and FIG. 3 is a throttle control processing operation performed by a throttle controller of the embodiment device. FIG. 4 is a natural frequency map, FIG. 5 is a damping coefficient map, FIG. 6 is a comparison diagram of a turning trajectory when an accelerator is turned off at a high lateral acceleration turning, FIG.
FIG. 8 and FIG. 8 are block diagrams showing another example of the lateral acceleration equivalent physical quantity detection unit. FIG. 9 is an accelerator without throttle control.
Characteristic diagrams of accelerator and throttle opening, drive shaft torque, and longitudinal acceleration during OFF operation. Fig. 10 shows accelerator and throttle opening, drive shaft torque, and longitudinal acceleration during accelerator OFF operation in model following throttle control. It is a characteristic diagram. a: accelerator opening detecting section b: throttle opening target value determining section c: lateral acceleration equivalent physical quantity detecting section d: tack-in operation determining means e: switching means f: throttle actuator g: throttle actuator control Department

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02D 41/04 F02D 9/02 351 F02D 29/02 311

Claims (1)

(57) [Claims] 1. An accelerator opening θ operated by a driver
An accelerator opening detection unit for detecting _A, and a throttle valve opening target value for receiving a signal from the accelerator opening detection unit and reducing torque fluctuation of the drive shaft.
And the throttle valve opening degree target value determination unit that determines the _{T ',} and the lateral acceleration corresponding physical quantity detection unit for detecting a lateral acceleration corresponding physical quantity Y _G of the vehicle, a signal from the accelerator opening detection section and the lateral acceleration corresponding physical quantity detecting unit And a tuck-in operation judging means for judging whether or not the accelerator is released during high lateral acceleration turning, and a throttle valve opening target value _T 'from the throttle valve opening target value determining section during normal accelerator operation. on which side of the valve opening final target value _T, at the time of accelerator release operation at high lateral acceleration turning, for a predetermined time, switches the accelerator opening theta _a on the side with the throttle valve opening final target value _T directly and switching means, with respect to the throttle actuator to the throttle valve opening final target value the actual throttle valve opening theta _T to _T matches Throttle control device, characterized in that comprises a throttle actuator control unit for outputting a control signal i, a.