JP2002187464A - Acceleration and deceleration controlling device for vehicle equipped with continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve control performance in acceleration and deceleration control after saturation of an operation quantity to a controlling object is settled. SOLUTION: This is a controlling means for calculating operation quantities TeL* and IpL* of an engine and a continuously variable transmission by a model following control method using a state space method. This controlling means is provided with a standard model 31 which outputs an acceleration command value α ref for indicating desirable responsivity for an acceleration estimated value αwf to a target acceleration αw*, an acceleration deviation integrator 32 which integrates deviation between the acceleration command value αref and the acceleration estimated value αwf, and a state feedback part 33 which calculates the operation quantities TeL* and IpL* by performing feedback of state quantities Xm and Xp of the standard model 31 and a controlling object, a vehicle model 35 and an acceleration deviation integrating quantity Xi. When it is detected that the operation quantities TeL* and IpL* are over the limit value, the operation quantities TeL* and IpL* are offset only for the quantities over the limit value. When all the operation quantities TeL* and IpL* are over each limit value, the integration of acceleration deviation by the acceleration deviation integrator 32 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling the acceleration / deceleration of a vehicle having a continuously variable transmission.

[0002]

2. Description of the Related Art As a model following control device using a state space method, as shown in FIG. 16, a state quantity x (t) of a control target (plant), a state quantity xm (t) of a reference model,
And the output ym (t) of the reference model and the output y (t) of the controlled object
There is known a model following servo controller which defines an expanded system in which all the integral values of the deviation e (t) from the deviation e (t) are state quantities and improves robustness by applying state feedback (for example, Guidance and Control in Space "Nishimura, Kanai, Murata, Corona
pp101-pp103).

Further, an acceleration / deceleration control device for a vehicle equipped with a continuously variable transmission such as a CVT to which the model following servo controller is applied is known (for example, see Japanese Patent Application Laid-Open No. H11-105584). In this device, while satisfying the engine operating point constraint condition determined based on the optimal fuel consumption operation line of the engine and the engine braking characteristic line at the time of fuel cut, that is, the relationship between the engine torque and the engine rotation speed, the first target An acceleration feedback compensator that calculates an engine torque command value and a gear ratio command value of a continuously variable transmission that are necessary to make the estimated driving force match the driving force, and controls them separately to achieve two command values simultaneously. Is composed.

[0004]

However, in the above-described conventional acceleration / deceleration control device for a vehicle having a continuously variable transmission, the output of the integrator in the servo compensator designed by the model following control is limited to two. There is a problem that the above-described simple method cannot deal with the problem of the saturation of the operation amount because the operation amounts affect one operation amount (engine torque command value and speed ratio command value). That is, if the integrator is temporarily stopped just because one operation amount is saturated, the other operation amounts are affected and sufficient tracking performance cannot be obtained. vice versa,
If the integrator is operated until both the operation amounts are saturated, the operation amount that has been saturated first becomes an inappropriately large value, and the response performance after the saturation is eliminated deteriorates.

An object of the present invention is to improve the control performance of acceleration / deceleration control after the saturation of the operation amount with respect to the control target is eliminated.

[0006]

FIG. 1 shows an embodiment of the present invention.
The present invention will be described with reference to FIG. 10 and FIG. 10. (1) The invention of claim 1 includes a vehicle speed detecting means 8 for detecting a vehicle speed, and an acceleration estimating means 4 for estimating a vehicle acceleration based on a detected vehicle speed value. A target acceleration setting means 4 for setting a target acceleration αw ^{* of the} vehicle, and an engine 1 and a continuously variable transmission 3 by a model following control method using a state space method.
Control means 4 for calculating the manipulated variables TeL ^* and IpL ^* of
Reference model 3 that outputs an acceleration command value αref indicating a desired response of the estimated acceleration value αwf to the target acceleration αw ^* .
1, the acceleration deviation integrator 32 for integrating the deviation between the acceleration command value αref and the estimated acceleration value αwf, and the state quantities Xm and Xp and the acceleration deviation integral Xi of the reference model 31 and the vehicle model 35 to be controlled are fed back. Manipulated variables TeL ^* , IpL ^*
Control means 4 having a state feedback unit 33 for calculating the operation amount, operation amount saturation detecting means 34 for detecting that the operation amounts TeL ^* and IpL ^* have exceeded their limit values, and operation amount TeL.
^*, IPL ^* the amount of operation by an amount that exceeds the limit value When exceeding the limit value TeL ^*, and offset means 34 for offsetting the IPL ^*, all operation amount TeL ^*, IpL ^* acceleration Once beyond the respective limit value And an integration stopping means for stopping integration of the acceleration deviation by the deviation integrator, thereby achieving the above object. (2) In the acceleration / deceleration control device for a vehicle provided with the continuously variable transmission according to the second aspect, the offset means gradually reduces the offset amount when all the operation amounts TeL ^* and IpL ^* become equal to or less than the respective limit values. This is set to 0. (3) The operation amount of the acceleration / deceleration control device for the vehicle including the continuously variable transmission according to claim 3 includes an engine torque command value and a gear ratio command value.

In the section of the means for solving the above-described problem, a diagram of one embodiment is used for easy understanding of the description, but the present invention is not limited to this embodiment. .

[0008]

(1) According to the first aspect of the present invention, even if there is a deviation in the saturation timing of each operation amount,
Even if one operation amount is saturated, the follow-up performance of the acceleration / deceleration control device is ensured by the other operation amount, and no useless integration of the saturated operation amount is performed. Operates linearly, so that the following performance of the acceleration / deceleration control device after saturation is not deteriorated, and the control performance is improved. (2) According to the second aspect of the invention, when the offset processing is repeated due to the saturation of the operation amount, the integrated value in the acceleration / deceleration control device drifts, so that it is difficult to secure the data range. become. That is, an inexpensive microcomputer having a short register length and capable of performing only integer operations cannot be used. However, if the offset amount is returned to 0 at a speed that does not degrade the control performance of the acceleration / deceleration control device, a drift of the integrated value in the acceleration / deceleration control device does not occur and the data range can be determined. That is, the apparatus cost can be reduced by using an inexpensive microcomputer.

[0009]

FIG. 1 shows a configuration of an embodiment. A power train of a vehicle according to one embodiment includes an engine 1, a torque converter 2 with a lock-up clutch, and a continuously variable transmission (CVT) 3. The engine 1 has an intake air amount control by an electronically controlled throttle valve actuator (not shown), a fuel injection control by an injector (not shown), and an ignition device (not shown).
The torque is controlled by ignition timing control or the like.

The lock-up clutch of the torque converter 2 with a lock-up clutch is released only in an extremely low speed range to enable the vehicle to stop and start, and to dampen vibration. On the other hand, in the middle to high speed range, the lock-up clutch is engaged to improve the transmission efficiency. The continuously variable transmission 3 adjusts the effective radii of the primary pulley and the secondary pulley on which the belts are stretched by a hydraulic mechanism (not shown) to make the speed ratio variable. The continuously variable transmission 3 is not limited to a belt type, and may be, for example, a toroidal type.

The acceleration / deceleration controller 4, the engine torque controller 5, and the CVT & clutch controller 6 are respectively a microcomputer, a ROM,
Peripheral circuits such as a RAM, an A / D converter, and various timers, a communication circuit, and a drive circuit for various actuators are provided, and communicate with each other via a high-speed communication line 13.

The acceleration / deceleration controller 4 performs a band-pass filter process on the detected vehicle speed to calculate the vehicle acceleration αwf
And the target acceleration αw ^*
, A desired response of the estimated acceleration value αwf is calculated, and the estimated acceleration value αwf is fed back to the acceleration command value αref of the reference model output as an acceleration detection value to perform acceleration feedback control. The acceleration / deceleration controller 4
An accelerator sensor 7 for detecting an amount of depression of an accelerator pedal (hereinafter referred to as an accelerator opening) Apo;
Is connected to a wheel speed sensor 8 for detecting a peripheral speed (hereinafter referred to as a wheel speed) Vw. The wheel speed Vw is equal to the vehicle speed Vsp.

The engine torque controller 5 controls the torque of the engine 1 by controlling the amount of intake air, controlling fuel injection, and controlling ignition timing. A crank angle sensor 9 for detecting the rotation speed ωe of the engine 1 is connected to the engine torque controller 5. The CVT & clutch controller 6 controls a hydraulic mechanism (not shown) to control the speed ratio of the continuously variable transmission 3. The CVT & clutch controller 6 has a primary speed sensor 10 for detecting the rotation speed ωp of the primary pulley of the continuously variable transmission 3 and the rotation speed ωs of the secondary pulley.
Is connected to a secondary speed sensor 11 for detecting the speed.

FIGS. 2 and 3 are flowcharts showing an acceleration / deceleration control program according to one embodiment. The operation of the embodiment will be described with reference to this flowchart. The microcomputer of the acceleration / deceleration controller 4 executes this control program at predetermined time intervals, for example, every 10 msec.

In step 1, the accelerator sensor 7
The accelerator opening Apo is read from. In step 2, the pulse signal from the wheel speed sensor 8 is measured, and the peripheral speed of the drive wheel 14 relative to the effective radius R of the tire, that is, the wheel speed V
w (= vehicle speed Vsp) is detected. In the following step 3, CV
The rotational speed ωp of the primary pulley (input shaft), the rotational speed ωs of the secondary pulley (output shaft) and the speed ratio Ip (= ωp / ωs) of the continuously variable transmission 3 are transmitted from the T & clutch controller 6 via the high-speed communication line 13. At the same time, the rotational speed ωe of the engine 1 is read from the engine torque controller 5 via the high-speed communication line 13.

In step 4, a target acceleration αw ^* is calculated based on the accelerator opening Apo and the wheel speed Vw. Specifically, as shown in FIG. 4, a map of the target acceleration αw ^* with respect to the wheel speed Vw is previously set using the accelerator opening Apo as a parameter, and the target acceleration αw ^* with respect to the detected accelerator opening Apo and wheel speed Vw ^. Is calculated. During the vehicle speed control, the target acceleration αw ^* is set according to the target vehicle speed setting operation by a set switch, an accelerator switch, a coast switch, or the like.

In step 5, a band pass filter process is performed on the wheel speed Vw to calculate an estimated acceleration value αwf.
Hereinafter, a method of calculating the estimated acceleration value αwf will be described.

First, a transfer function Gbp (s) of a continuous time system in which the wheel speed Vw is input and the estimated acceleration value αwf is output is described as follows.

(Equation 1) In the expression (1), s is a Laplace operator, ωn is a natural angular frequency, Δn is an attenuation rate, and ωn and Δn are determined in advance by an experiment according to a noise level included in the detected wheel speed value Vw.

Next, when this transfer function Gbp (s) is converted into an expression by a state vector, it is represented by a block diagram shown in FIG. 5, and a state equation and an output equation using the state variable vector Xf are as follows. Is described. _

(Equation 2) In the equation (2), Af, Bf, Cf, and Df are constant matrices determined from the natural angular frequency ωn and the attenuation rate ζn.

In order to calculate an internal state variable vector Xf of the band-pass filter in addition to the estimated acceleration value αwf which is an output of the band-pass filter, a continuous-time state equation and an output equation shown in the equation (2) are used. Perform the operation. If the integration operation is Euler integration in order to design a state feedback compensator for acceleration control in a continuous time system, the state equation and the output equation of the above equation (2) can be actually executed by microcomputer software. It can be expressed as a simple difference equation as follows.

(Equation 3) In the equation (3), Tsmp is a sampling period,
In this embodiment, the execution interval of the program shown in FIGS. 2 and 3 is 10 msec. (K) is the current value, (k
-1) indicates a value before one sampling period, and (k + 1) indicates a value after one sampling period. The estimated acceleration value αwf is obtained by executing the equation (3).

In step 6, the engine torque command value T
Assuming the actual engine torque Te to a simple first-order lag model from e ^*, and estimates the actual engine torque Te to the engine torque command value Te ^*. First, a transfer function Geng of a continuous time system from the engine torque command value Te ^* to the engine torque estimated value Te is described as follows. _

(Equation 4) In the equation (4), Teng is a time constant.

The equation (4) is discretized by Tustin approximation or the like, and a difference equation that can be actually executed by microcomputer software is obtained and executed.

(Equation 5) In equation (5), TEN0, TEN1, and TED1 are constants determined from the time constant Teng and the sampling period Tsmp.

In step 7, the engine rotational speed ωe corresponding to the estimated engine torque Te is looked up from a preset engine operating point constraint line map as shown in FIG. Engine Operating Point Restraint Line Map In FIG. 6, the engine optimum fuel consumption (efficiency) operating line is used as a restraining line in a positive torque range, and the engine brake characteristic line is used as a restraining line in a negative torque range. Note that the engine optimum fuel consumption operation line is a characteristic line connecting engine operation points on the output line such as the engine where the fuel consumption is the smallest. The engine brake characteristic line is a characteristic line connecting the engine operating point at the time of fuel cut when the throttle valve is fully closed. By controlling along the engine brake characteristic line, the downshift of the continuously variable transmission 3 is performed. Enables engine brake control at the time.

Here, considering the state in which the lock-up clutch of the torque converter 2 is engaged, the engine rotation speed ωe is equal to the rotation speed ωp of the primary pulley (input shaft) of the continuously variable transmission 3. Therefore, the engine rotation speed ωe obtained by performing a lookup operation from the map shown in FIG. 6 is set as a target primary pulley rotation speed (input shaft rotation speed of the continuously variable transmission) ωp ^* . Then, a value Z is calculated by integrating the deviation between the target primary pulley rotation speed ωp ^* and the actual rotation speed ωp of the primary pulley.

(Equation 6)

In step 8, an operation region determination for performing gain switching by acceleration feedback control is performed. In this embodiment, as shown in FIG.
The operating range is divided into six based on the value of w and the sign of the input torque Tp of the continuously variable transmission 3, and gain switching is performed. In addition,
When the lock-up clutch of the torque converter 2 is engaged, the input torque Tp of the continuously variable transmission 3 is equal to the engine torque Te. If the operation area one sampling cycle before and the current operation area are the same area, step 10 is executed.
If not, the process proceeds to step 9.

In step 9, in preparation for switching of the state feedback gain, the initial values of the two integrators in the acceleration control feedback compensator are calculated. Specifically, from the state feedback gain constant matrix corresponding to each operation region stored in the ROM in advance, Kold corresponding to the operation region one sampling cycle before and Knew corresponding to the current operation region are selected. Using the following equation obtained by solving the equation (17) of the state feedback operation described below, so that the compensator output U continuously changes before and after the gain switching.
An initial value Xi_ini of the acceleration deviation integrator and an initial value Zini of the primary pulley rotation speed deviation integrator are calculated.

(Equation 7)

In step 10, the operation of the acceleration control feedback compensator is performed. In this embodiment,
The vehicle acceleration / deceleration is controlled by "model following control method using state space method" which is one of the practical linear control methods. The control system design method will be described below.

First, a plant model is derived. FIG.
A non-linear vehicle model that receives a continuously variable transmission input torque command value Tp ^* and a speed ratio command value Ip ^* and outputs a drive wheel acceleration αw and a continuously variable transmission primary rotation speed ωp as shown in FIG. A model linearly approximated by (Tpo, Ipo, ωwo) is shown in the following equation.

(Equation 8) In equation (8), ωw is the drive wheel rotation speed (Vw = R · ω
w). T1 is the time constant of the engine torque system (T
1 = Teng), T2 is the time constant of the continuously variable transmission ratio servo system, M is the vehicle weight, If is the final gear ratio, and J1 is the inertia from the engine 1 to the primary pulley of the continuously variable transmission 3.

For this linearly approximated vehicle model,
An enlarged system model obtained by combining the bandpass filter model shown in the equation (2) and the deviation integral model relating to the above-described engine operating point constraint condition is defined as a plant model for control system design. Note that, for the deviation integral model relating to the engine operating point constraint condition, the following equation obtained by linearly approximating the nonlinear map at a specific point is used.

(Equation 9) In the equation (9), ka is a constant.

The above expanded system plant model is represented by a block diagram using a state vector as shown in FIG. 9, and is described as follows in the form of a state equation and an output equation of a continuous time system. However, when the lock-up clutch of the torque converter 2 is engaged, the input torque Tp of the continuously variable transmission 3 is equal to the engine torque Te.

(Equation 10) Equation (10) is a state equation and an output equation having two inputs, one output and six states, and Ap, Bp, Cp, and Dp are constant matrices shown in the following equations.

[Equation 11] Tp ^* is an input torque command value of the continuously variable transmission 3, and Ip ^* is a speed ratio command value of the continuously variable transmission 3. Further, Xf1, X
f2 is an element of the internal state variable vector Xf of the bandpass filter shown in the equation (2).

Acceleration estimated value αwf for target acceleration αw ^*
Is defined as a first-order lag, and its transfer function, state equation, and output equation are expressed as follows.

(Equation 12) In the equation (12), Tαw is a time constant. The reference model executes the equation (12) to calculate the acceleration command value α indicating the desired response of the estimated acceleration value αwf to the target acceleration αw ^* .
Output ref.

FIG. 10 shows a control block diagram in the case where an acceleration servo system is formed by using a model following control method based on state feedback for the above-described expanded system plant model and reference model. In FIG. 10, a thick line represents a vector, and a thin line represents a scalar. The gain K (constant matrix) of the state feedback unit 33 is obtained by using a general optimal regulator method or the like with respect to the following coupled model (Equation (13)) in which the expanded plant model 35 and the reference model 31 are further coupled. Can be. However,
The acceleration command value αref and the estimated acceleration value αw of the reference model 31
Let Xi be the integral of the deviation integrator 32 with f.

(Equation 13)

By constructing such an acceleration servo compensator, the acceleration command value αre output from the reference model 31 is obtained.
The acceleration estimation value αwf follows f without a steady-state deviation. At the same time, the state feedback 33 stabilizes all state variables. That is, the deviation integral amount Z of the primary pulley rotation speed ωp of the continuously variable transmission 3, which is one of the state variables, is also stabilized, and as a result, the actual rotation speed ωp becomes the target rotation speed ωp ^* of the continuously variable transmission primary pulley. Follow without steady-state deviation.

Next, the actual processing executable by the microcomputer software is represented in the form of a difference equation.
First, the calculation of the reference model 31 is performed by the following difference equation.

[Equation 14] In Expression (14), MAN0, MAN1, and MAD1 are constants obtained by discretizing Expression (12) by Tustin approximation or the like.

Next, acceleration deviation integration is performed by a deviation integrator 32 between the acceleration command value αref and the estimated value αwf. An engine torque command value saturation flag fTe_lmt indicating a saturation state of the engine torque command value Te ^* , and a gear ratio command value saturation flag fIp_lmt indicating a saturation state of the gear ratio command value Ip ^*.
Are set (= 1), that is, when both the engine torque command value Te ^* and the speed ratio command value Ip ^* are in a saturated state, the acceleration deviation integral calculation is executed by the following equation.

(Equation 15) If one of the engine torque command value Te ^* and the gear ratio command value Ip ^* is not in a saturated state, the acceleration deviation integral calculation is executed by the following equation.

(Equation 16) Note that the engine torque command value saturation flag fTe_lmt and the gear ratio command value saturation flag fIp_lmt are set in step 16 described later.
Is a flag that is set or reset (= 0) by
Here, (1)
The deviation integral calculation of the acceleration is performed by the expression 5) or the expression (16).

As is clear from the comparison between the equations (15) and (16), the equation (15) shows the term of the current deviation between the acceleration command value αref and the estimated value αwf (Tsmp · ｛αref (k) − αwf
(k)｝) is not included, and the previous deviation integral Xi (k-1) between the acceleration command value αref and the estimated value αwf is replaced by the current deviation integral X
Just set it to i (k). That is, when both the engine torque command value Te ^* and the speed ratio command value Ip ^* are in a saturated state, the acceleration command value αref and the estimated value αw are calculated by the equation (15).
Stop deviation integration with f. If either one of the engine torque command value Te ^* and the gear ratio command value Ip ^* is not saturated, the acceleration command value αref is calculated according to (16).
And the integral of the deviation of the estimated value αwf.

Further, the state feedback section 33 executes a state feedback calculation by the following equation.

[Equation 17] Then, the engine torque command value Te ^* is determined as follows.

(Equation 18)

[Equation 19] In equation (19), K is a function of the torque converter slip ratio. Whether the lock-up clutch is engaged or not engaged is detected by the CVT & clutch controller 6 and transmitted to the acceleration / deceleration controller 4 via the high-speed communication line 13.

Next, in steps 11 to 16, FIG.
The operation of the saturation processing unit 34 for the engine torque command value Te ^* and the gear ratio command value Ip ^{* shown} in FIG. In step 11,
Conditional branching is performed according to the setting state of the command value saturation flags fTe_lmt and fIp_lmt set or reset one sampling cycle before. Command value saturation flags fTe_lmt and fIp_lmt
If at least one of these is set, the process proceeds to step 12, and if both are reset, the process proceeds to step 13.

When one or both of the command value saturation flags fTe_lmt and fIp_lmt are set, that is, one or both of the engine torque command value Te ^* and the speed ratio command value Ip ^* are saturated. In this case, in step 12, the command value offset request flags fTe_ofs and fIp_ofs are set for the saturated command value, and
The offset amounts Δe_1 and Δp_1 are calculated using the command values Te_ofs ^* and Ip_ofs ^* after the offset processing calculated in step 16 described later before the sampling period.

(Equation 20)

On the other hand, the command value saturation flags fTe_lmt, fIp_l
If both mt are reset, that is, if both the engine torque command value Te ^* and the speed ratio command value Ip ^* are not saturated, in step 13, the command value offset request set or reset one sampling cycle before is set. Conditional branching is performed according to the setting states of the flags fTe_ofs and fIp_ofs. That is, the command value offset request flag fTe_ofs,
If at least one of fIp_ofs is set, the process proceeds to step 14, and if both are reset, the process proceeds to step 15.

Command value offset request flag fTe_ofs, f
When one or both of Ip_ofs are set, that is, both the engine torque command value Te ^* and the speed ratio command value Ip ^* are not saturated, but those command values Tp
If there is an offset request for one or both of e ^* and Ip ^* , at step 14, the command values Te ^* and Ip ^*
As the processing immediately after the saturation of the offset has been eliminated, the offset amount Δ according to the command value offset request flags fTe_ofs and fIp_ofs
The values of e_1 and Δp_1 are shifted to offset amounts Δe_2 and Δp_2, and the offset amounts Δe_1 and Δp_1 are cleared. further,
The command value offset request flags fTe_ofs and fIp_ofs are also cleared.

(Equation 21)

On the other hand, the command value offset request flag fTe_o
When both fs and fIp_ofs are reset, that is, both the engine torque command value Te ^* and the speed ratio command value Ip ^* are not saturated, and an offset request is issued for those command values Te ^* and Ip ^* . If not, it is determined that the saturated command value (operating amount) has turned to the decreasing side, and step 15
In order to slowly return the offset amounts Δe_2 and Δp_2 to 0, the offset amounts Δe_2 and Δp_2
Is reduced by a predetermined number of times. As a result, the correction is gradually shifted to the integrator 32 in the servo compensator.

In step 16, an offset process is performed on each of the command values Te ^* and Ip ^* by the following equation.

(Equation 22) Further, the offset-processed engine torque command value T
e_ofs ^* and the speed ratio command value Ip_ofs ^* determine whether or not the limit value has been reached, and a command value saturation flag fTe_lm
t or fIp_lmt is set or reset. Limit values Te_lmt, Ip_lmt of the engine torque Te and the gear ratio Ip
Indicates a limit value of an area achievable by the engine torque controller 5 and the CVT & clutch controller 6, but in this embodiment, description is made without distinguishing between an upper limit value and a lower limit value. Each command value Te ^* ,
If Ip ^* reaches the limit value, each command value saturation flag fTe_lmt, fIp_lmt is set, otherwise reset. It should be noted that the limit values Te_lmt and Ip_lmt are the vehicle state quantities such as the engine speed ωe and the vehicle speed Vsp, respectively.
Is obtained from a predetermined table data shown in FIG.

In step 17, the engine torque command value TeL ^* after the saturation processing is
Then, the gear ratio command value IpL ^* after the saturation processing is output to the CVT & clutch controller 6 via the high-speed communication line 13. The engine torque controller 5 controls the engine torque Te to match the command value TeL ^* ,
The T & clutch controller 6 controls the speed ratio Ip of the continuously variable transmission 3 so as to match the command value IpL ^* .

Next, the result of the command value saturation processing will be described.
FIG. 12 shows a processing result by the conventional control device. FIG.
(a) shows an engine torque command value Te ^* and a gear ratio command value Ip ^*.
This is a conventional command value saturation processing result of stopping the integrator in the servo compensator during the period from t2 to t3 when both of the two manipulated variables 1 and 2 reach the limit value. In this case, there is a time delay in which the manipulated variable 1 that has reached the upper limit value and is saturated earlier is reduced to the limit value, and the tracking performance of the servo system after the saturation of the manipulated variable 1 is degraded.

FIG. 12B shows that the servo compensator is operated during the period t1 to t4 during which either the operation amount 1 of the engine torque command value Te ^* or the speed ratio command value Ip ^* reaches the limit value. It is a conventional command value saturation processing result of stopping the integrator.
In this case, the operation amount 2 that has not yet been saturated by stopping the integrator cannot provide a sufficient effect, and the tracking performance of the servo system also deteriorates.

FIG. 13 shows a command value saturation processing result according to the above-described embodiment of the present invention. In the above-described embodiment, since the previously manipulated variable 1 is offset by the amount exceeding the limit value, when the increasing / decreasing direction of the manipulated variable 1 is reversed, the operation value 1 can be immediately started from the limit value. The following performance of the system does not deteriorate. In addition, the acceleration deviation integrator 32 in the servo compensator functions until the two manipulated variables 1 and 2 are saturated (up to t2). The follow-up performance of the servo system is secured by the other operation amount 2.

FIG. 14 shows a simulation result by the conventional control device, and FIG. 15 shows a simulation result by the one embodiment. In these figures, (a)
Indicates an estimated acceleration value αwf for the target acceleration αw ^* ,
(B) shows the actual rotation speed ωp of the continuously variable transmission primary pulley with respect to the target rotation speed ωp ^* . (C) shows the estimated engine torque value Te for the engine torque command value Te ^* , and (d) shows the actual speed ratio Ip for the continuously variable transmission speed ratio command value Ip ^* . (E) shows the vehicle speed Vsp
Is shown.

When the target acceleration αw ^* is changed stepwise, the engine torque command value Te ^* temporarily increases to exceed the limit value in order to quickly follow the reference model. In the conventional control device that does not perform the offset processing, the engine torque command value Te ^* greatly deviates from the estimated engine torque Te, and thereafter, the overshoot or undulation of the estimated acceleration value αwf occurs (see FIG. 14). On the other hand, in the above-described embodiment in which the offset processing is performed, unpleasant overshoot is sufficiently reduced, and good acceleration performance is realized (see FIG. 15).

As described above, in one embodiment described above,
An acceleration feedback compensator that calculates an engine torque command value Te ^* and a gear ratio command value Ip ^* , which are operation amounts of the engine 1 and the continuously variable transmission 3, by a model following control method using a state space method, A reference model 31 that outputs an acceleration command value αref indicating a desired response of the estimated acceleration value αwf to the target acceleration αw ^*, and an acceleration command value αr
ef and the acceleration deviation integrator 32 that integrates the deviation between the estimated acceleration value αwf, and the operation amount Te by feeding back the state amount Xm of the reference model 31 and the state amount Xp of the vehicle model 35 to be controlled to the acceleration deviation integration amount. ^* includes an acceleration feedback compensators and a state feedback unit 33 for calculating the Ip ^*, the operation amount Te ^*, detects that Ip ^* exceeds its limit value, the operation amount Te ^*, Ip ^* is a limit value The operation amounts Te ^* and Ip ^* are offset by an amount exceeding the limit, and the integration of the acceleration deviation by the acceleration deviation integrator 32 is stopped when all the operation amounts Te ^* and Ip ^* exceed their respective limit values. . As a result, the two manipulated variables Te ^* and Ip ^*
Even if there is a deviation in the saturation timing, even if one of the operation amounts saturates, the tracking performance of the servo system is secured by the other operation amount, and no useless integration of the saturated operation amount is performed. Since the acceleration feedback compensator operates linearly immediately after the cancellation, the following performance of the servo system after the saturation is eliminated does not deteriorate, and the control performance is improved.

In the above-described embodiment, when all of the manipulated variables Te ^* and Ip ^* become equal to or less than the respective limit values, the offset amount is gradually set to zero. When the offset processing is repeated due to the saturation of the manipulated variables Te ^* and Ip ^* , the integrated value in the feedback compensator drifts, and it becomes difficult to secure the data range. That is, an inexpensive microcomputer having a short register length and capable of performing only integer operations cannot be used. However, if the offset amount is returned to 0 at a speed that does not degrade the control performance of the acceleration feedback compensator, drift of the integrated value in the acceleration feedback compensator does not occur, and the data range can be determined. That is, the apparatus cost can be reduced by using an inexpensive microcomputer.

In the above-described embodiment, an example has been described in which the engine torque command value and the gear ratio command value are used as operation amounts, but the operation amounts are not limited to these physical amounts.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment.

FIG. 2 is a flowchart showing an acceleration / deceleration control program according to one embodiment.

FIG. 3 is a flowchart showing an acceleration / deceleration control program according to one embodiment, following FIG. 2;

FIG. 4 is a diagram showing an example of a map of a target acceleration αw ^* with respect to a wheel speed Vw using an accelerator opening Apo as a parameter.

FIG. 5 is a block diagram illustrating a transfer function using a wheel speed Vw as an input and an estimated acceleration value αwf as an output as a state vector.

FIG. 6 is a diagram showing an engine operating point constraint line map.

FIG. 7 is a diagram illustrating an example of division of an operating region based on a wheel speed Vw and a continuously variable transmission input torque Tp.

FIG. 8 is a block diagram showing a non-linear vehicle model in which a continuously variable transmission input torque command value Tp ^* and a speed ratio command value Ip ^* are input and a drive wheel acceleration αw and a continuously variable transmission primary rotation speed ωp are output. is there.

FIG. 9 is a block diagram showing an enlarged plant model by a state vector.

FIG. 10 is a control block diagram in a case where an acceleration servo system is configured by using a model following control method based on state feedback in an enlarged system plant model and a reference model.

FIG. 11 is a diagram showing limit values of an engine torque Te and a gear ratio Ip with respect to an engine rotation speed ωe and a vehicle speed Vsp.

FIG. 12 is a diagram showing a result of a command value saturation process by a conventional device.

FIG. 13 is a diagram showing a command value saturation processing result according to an embodiment of the present invention.

FIG. 14 is a diagram showing a simulation result of acceleration / deceleration control by a conventional device.

FIG. 15 is a diagram showing a simulation result of one embodiment according to the present invention.

FIG. 16 is a diagram showing a configuration of a conventional acceleration / deceleration control device for a vehicle including a continuously variable transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Torque converter with lock-up clutch 3 Continuously variable transmission 4 Acceleration / deceleration controller 5 Engine torque controller 6 CVT & clutch controller 7 Accelerator sensor 8 Wheel speed sensor 9 Crank angle sensor 11 Primary speed sensor 12 Secondary speed sensor 13 High speed communication line 14 Drive wheel 31 Reference model 32 Acceleration deviation integrator 33 State feedback unit 34 Saturation processing unit 35 Expansion plant model

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02D 45/00 358 F02D 45/00 358M F02P 5/15 F16H 9/00 A F16H 9/00 61/02 61 / 02 59:14 // F16H 59:14 59:44 59:44 59:46 59:46 63:06 63:06 F02P 5/15 FF term (reference) 3D041 AA31 AA66 AB01 AC01 AC15 AC20 AD02 AD04 AD10 AD31 AD51 AE03 AE04 AE07 AE09 AE31 AE36 3G022 CA04 CA05 EA06 FA08 GA01 GA05 GA08 GA19 GA20 3G084 BA05 BA13 BA17 CA04 CA06 DA05 EA01 EA05 EA09 EA11 EB08 EB24 EC04 FA05 FA06 FA10 FA32 FA33 FA03 3G301 JA03 NB04 ND45 PE01Z PE03Z PE06Z PF01Z PF02Z PF03Z PF07Z 3J552 MA07 MA09 MA12 NA01 NB03 NB04 PA32 PA33 RB15 RB18 SA34 SA44 TA01 TB11 TB13 TB18 UA08 VA32Y VA36Y VB01W VB04W VC01Z VC03Z VD02W

Claims (3)

[Claims] A vehicle speed detecting means for detecting a vehicle speed; an acceleration estimating means for estimating a vehicle acceleration based on the detected vehicle speed value; a target acceleration setting means for setting a target acceleration of the vehicle; A control unit for calculating an operation amount of the engine and the continuously variable transmission by a model following control method, a reference model for outputting an acceleration command value indicating a desired response of the estimated acceleration value to the target acceleration, and an acceleration command value; A control having an acceleration deviation integrator that integrates a deviation from an estimated acceleration value, and a state feedback unit that calculates the operation amount by feeding back the state amount of the reference model and the vehicle model to be controlled and the acceleration deviation integral amount. Means, an operation amount saturation detecting means for detecting that the operation amount exceeds the limit value, and a reset when the operation amount exceeds the limit value. Offset means for offsetting the operation amount by an amount exceeding the set value, and integration stop means for stopping integration of the acceleration deviation by the acceleration deviation integrator when all the operation amounts exceed respective limit values. An acceleration / deceleration control device for a vehicle including a continuously variable transmission. 2. The acceleration / deceleration control device for a vehicle provided with a continuously variable transmission according to claim 1, wherein said offset means gradually reduces the offset amount when all of said operation amounts are equal to or less than respective limit values. 0
An acceleration / deceleration control device for a vehicle including a continuously variable transmission. 3. The acceleration / deceleration control device for a vehicle equipped with a continuously variable transmission according to claim 1, wherein the operation amount includes an engine torque command value and a gear ratio command value. A vehicle acceleration / deceleration control device including a continuously variable transmission.