JPS62191239A - Device for controlling continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent a sudden engine brake action or the overrun of an engine by operating a feedback control using an integral value of deviation when a vehicle speed signal becomes zero. CONSTITUTION:The feed forward control position of a speed change actuator is determined based on both or either of a vehicle speed or an engine load by a feed forward control means. At the same time, the target value of the input speed of rotation or the change gear ratio of a continuously variable transmission is determined by a target determining means. Then, the deviation between this target value and an actual value is operated by a deviation operating means and, then, integrally processed by an integral means. And, by adding a feedback control quantity based on the deviation and the integral value to the feed forward control position, a speed change signal is outputted to the speed change actuator, from a first speed change commanding means when a signal which indicates a vehicle speed is not zero while the deviation is above a defined value, and, from a second speed change commanding means when a signal which indicates a vehicle speed is zero or when deviation is below the defined value.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a control device for a continuously variable transmission.

(b) Conventional technology As a conventional continuously variable transmission control device, for example,
There is one shown in Publication No. 0-81560. This continuously variable transmission control device includes a feedforward control control unit 1i determining means, a feedback control amount determining means, and a r141 means for selecting whether to perform feedback control or feedforward control. During feedback control, a shift command is issued using a signal that is the sum of a feedforward control amount and a feedback control amount, and during feedforward control, a shift command is issued using a feedforward control amount. This makes it possible to switch between feedback control and open-loop control depending on the operating conditions, correcting gear ratio errors, and creating a control system for continuously variable transmissions that does not cause hunting. can do.

(C) Problems to be Solved by the Invention However, in the conventional control device for the above-mentioned non-speed transmission, if the vehicle speed sensor fails while the vehicle is running, the maximum gear ratio state is commanded, and the control device suddenly There is a problem in that the engine brake is applied and the engine may overrun. In other words, vehicle speed sensor failure;
When a signal indicating the vehicle speed is not output due to a disconnection or the like, the feedforward control amount determining means determines that the vehicle speed is 0 and instructs the maximum gear ratio. If this occurs while the vehicle is running, sudden engine braking is applied, and in some cases, the engine may overrun. The present invention aims to solve these problems.

(d) Means for solving the problem The present invention solves the above problem by increasing the amount of feedback by activating feedback control using the integral value of the deviation in the case of a vehicle speed sensor failure. . That is, the present invention provides feedforward control means that determines the feedforward control position of a speed change actuator based on both or either of vehicle speed and engine load, and a continuously variable transmission that determines a feedforward control position of a transmission actuator based on both or either of vehicle speed and engine load. target value determining means for determining the target value of the input rotational speed or gear ratio; deviation calculation means for calculating the deviation between the actual value of the input rotational speed or transmission ratio and the target value; and the deviation calculated by the deviation calculation means. It is applied to a control device having an integrating means for performing an integral process, and when the signal indicating the vehicle speed is not 0 and the deviation is larger than a predetermined value, the integrating means is reset to the initial state, A first shift command means adds a feedback control amount based on the deviation to the feedforward control position and outputs a shift command signal to the shift actuator, and a first shift command means outputs a shift command signal to the shift actuator.
or second shift command means for adding a feedback control amount based on the deviation and the integral value to the feedforward control position and outputting a shift command signal to the shift actuator when the deviation is smaller than the predetermined value. The gist is:

(e) Effect When the vehicle speed sensor is normal, the following effects are obtained. In other words, when the deviation is large, a feedback control amount corresponding to the deviation is added to the feedforward control position, thereby achieving quick shift response, and - when the force deviation is small, the feedback control amount is added to the feedforward control position. A feedback control amount corresponding to the deviation and its integral value is added, thereby performing stable speed change control.

When the signal indicating the vehicle speed becomes 0 due to a failure of the vehicle speed sensor, etc., the same control as when the deviation is small is performed. In this case, the feedforward control means will instruct the maximum gear ratio. If such a situation occurs while driving, a large deviation will occur. Since the feedback control amount is determined according to the deviation and its integral value,
It gradually increases. Therefore, changes in the feedforward control position can be compensated for by the feedback control amount, and sudden changes in the gear ratio can be prevented.

(F) Embodiment FIG. 2 shows a power transmission mechanism of a continuously variable transmission whose speed change is controlled by the control device of the present invention. In this continuously variable transmission, the rotation of the human-powered shaft 2 is controlled by the drive pulley 6, belt 50,
Output +1+1h76 and 78 via driven pulley 51 etc.
It can be communicated to. This continuously variable transmission has two human-powered shafts.
, +i7r advancement clutch 4, drive pulley 6, drive ll1
h a, oil pump 10, driving gear 12, driven gear 1
4. Rotating groove 16, oil pool 18, pitot tube 20, subshaft 22, reverse clutch 24, gear 26, 28, 30, 3
2 and 34, piston chambers 36 and 38, fixed circular plate 4
0, Drive pulley cylinder chamber 42, Movable conical plate 44, Rotating groove 46, Oil pool 47, Pitot tube 48, ■ Heald 5
0, driven pulley 51, driven shaft 52, fixed conical plate 54,
Driven pulley cylinder chamber 56, splinter 57, movable conical plate 58, gear 60, ring gear 62, differential case 64
, pinion gears 66 and 68, a differential device 70, side gears 72 and 74, and output shafts 76 and 78, detailed explanations of which will be omitted.

The structure of the parts whose explanation is omitted is described in Japanese Patent Laid-Open No. 59-75840 "Control Device for Hydraulic Automatic Clutch" filed by the present applicant.

FIG. 3 shows a hydraulic control device for a continuously variable transmission.

The hydraulic control device for this continuously variable transmission includes an oil pump 10,
Line pressure regulating valve 102, manual valve 104, speed change control valve 106, clutch complete engagement control valve 108, speed change motor (
step motor) 110 (speed change actuator), speed change control mechanism 112, throttle valve i"l 14, starch ink valve 116, start adjustment valve 118, maximum speed ratio holding valve 120, reverse inhibitor valve 122, lubrication valve 12
4, a tank 130, etc., which are connected to each other as shown in the figure, and a piston chamber 36 of the forward clutch 4, a piston chamber 38 of the reverse clutch 24, a driving pulley cylinder chamber 42, and a driven pulley. cylinder chamber 56,
It is also connected to the pitot tubes 20 and 48. A detailed explanation of these valves and the like will be omitted. For the parts omitted from explanation, please refer to the above-mentioned Japanese Patent Application Laid-open No. 59/75840.
It is stated in the No.

Step motor 110 (speed change actuator) is shown in Fig. 4.
1) shows a speed change control device 300 that controls the operation of the force motor 224. The speed change control device 300 includes an input interface 311, a CPU (central processing unit) 313,
Reference pulse generator 312, ROM (read-only memory 314, RAM (random access memory) 31
5. Non-volatile memory 322 and output interface 3
16, which are connected by an address bus 319 and a data bus 320, and this transmission control device 300 includes an engine rotation speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, a shift position switch 304, Shift reference switch 298
(shift reference position sensor), engine coolant temperature sensor 306, brake sensor 307, and start pressure detection pressure sensor 321 are input, and signals are output to the step motor 110 and force smoke 224. The explanation will be omitted. Note that the structure of the parts whose explanation is omitted is described in the above-mentioned Japanese Unexamined Patent Publication No. 59
It is described in the publication No.-75840.

FIG. 5 shows a force motor control routine 500, and FIG. 6 shows a complete engagement control routine 600.

These details are the same as those in the above-mentioned Japanese Patent Application Laid-Open No. 1983-75840, so detailed explanations will be omitted.

Following the complete engagement control routine 600, a step motor control routine 700 shown in FIGS. 7-9 is executed.

First, the shift position is read (step 70).
5), then determine whether it is in the D range or not (707),
In the case of D range, D range target turbine rotation speed TR
A PM search is performed (902). If it is not the D range at step 707, it is determined whether it is the first range (step 709), and if it is the L range, the L range target turbine rotational speed TRPM is searched (step 904). In step 902 or step 904, the target turbine rotation speed TR
After completing the PM search, the vehicle speed Vs is read (906), and then the step motor position O5 is calculated based on TRPM and Vs (908).

This O5 is a quantity indicating the feedforward control position. Next, read the actual Tahin rotational speed Nt (Same 9
10) Calculate the deviation e between the target turbine rotational speed TRPM and the actual turbine rotational speed Nt (912). Next, it is determined whether Vs=O or not (913),
When Vs=O, the value of deviation e should be set to el.
5) Proceed to step 924, which will be described later, and if Vs=O, the absolute value of the deviation e is set to a predetermined value C2 (for example,
300rpm) to determine whether it is smaller than 91
4) If the absolute value of e is smaller than C2, set the value of deviation e to el (916), step 924 described below.
Proceed to.

Also, if the absolute value of the deviation e is greater than 02, then e
is larger than 0 (918), and if e is larger than 0, set the value of C2 to el, and if the value of e is negative, set -C2 to 81. 922
), proceed to step 924. In step 924, el obtained as described above is multiplied by a constant p, and this value is set to P
shall be. This value of P is the deviation-corresponding portion of the feedback control amount. Next, the absolute value of the deviation e becomes a predetermined value C+(
For example, if the absolute value of e is smaller than CI, summer is determined as the integral of e multiplied by a constant (Ibid. 928). ). In addition, if the absolute value of e is larger than C3, it is necessary to determine whether Vs = 0 or not (I'11), and further determine whether NT = O (I'11) (927).
1), if Vs=0 or NT=o, set the value of deviation e to 8
．． 929), the process proceeds to step 928 described above, and if Vs=O and NT=O, then 2 is set to 0. Note that step 931 is for resetting the integrator while the vehicle is stopped when the vehicle speed sensor is normal. In other words, reset the integrator (see 9.
30). From step 928 or step 930, the process proceeds to step 932, where the sum of ■ and P is set as DPi. This DPi is the feedback control amount. Next, the above-mentioned θS and Dpi are added and this is determined as the target pulse number N. or NL (ibid. 934). Note that N is for the D range, and NL is for the lower range.

Then N. Or, NL is a value smaller than the number of pulses corresponding to the limit value on the large speed ratio side; it is necessary to judge whether it is negative (see 936), and if N or N is negative, the integral value addition should be stopped. 938), then set Ds to O, 9
40), proceed to step 778. Also, step 936
If No or NL is 0 or more, it is determined whether No or NL is larger than a predetermined value Hi, which is a value corresponding to the minimum gear ratio within the speed change range of the continuously variable transmission.
42), If No or NL is smaller than Hi, proceed directly to step 778, and if N or N is larger than Hi, stop the integral value addition (944),
Next, Ds is set to Hi (946), step 77.
Proceed to step 8. Step 778 et seq. and step 70 above.
9 and not the L range (that is, the R, P, and N ranges) is described in the above-mentioned Japanese Patent Application Laid-Open No. 59-7584.
Same as No. 0.

In the end, the following control will be performed by the above-mentioned routine. First, in step 908, the feedforward control position is calculated.

In step 924, the deviation corresponding portion P of the feedback control amount is calculated, and in step 928, the integral value corresponding portion I of the deviation is calculated. In step 932, the feedback control amount Dpi is calculated by adding ■ and P.

When the absolute value of the deviation e is smaller than 02 or when the signal indicating the vehicle speed is 0, the value of the deviation e multiplied by a constant p is taken as the value of P. Therefore, the value of P is the actual deviation e
It is a value that changes in proportion to. On the other hand, if the absolute value of the deviation e is larger than C2, P is the constant value C2 multiplied by Kp. Therefore, the value of P is always a constant value. As a result, even if a large deviation occurs, the value of P will not exceed a predetermined value.

Further, when the absolute value of the deviation e is smaller than the predetermined value C1, I is the integral value of el multiplied by the constant Ki.

Also, if the absolute value of the deviation e is larger than the predetermined value C1, and the signal indicating the vehicle speed is 0, and the actual turbine rotational speed NT
When is not 0, it becomes the integral value of the actual deviation e multiplied by a constant Ki, or ■. However, the absolute value of the deviation e is CI
If the signal indicating the heavy speed is not 0 and the actual turbine rotational speed is N7 or O, the value of ■ is reset to 0.

Therefore, if the signal indicating the vehicle speed is 0 (for example, if the vehicle speed sensor 301 is broken), add the integral value (1) of the actual deviation e to the value (P) proportional to the actual deviation e. The value obtained is the feed parameter control amount (Dpi).

The step motor 110 is controlled by adding the feed forward control position (O5) to the feed forward control position (O5).Since the vehicle speed is determined to be 0, the feed forward control position corresponds to the maximum gear ratio. For example, the control amount becomes 0. On the other hand, the actual deviation is integrated and added, so it increases as long as there is a deviation.

The decrease in the feedforward control position is compensated for by the feedback control amount, and the command signal to the step motor 110 does not decrease to the maximum gear ratio, thereby preventing a sudden change in the gear ratio. Furthermore, when it is determined that the vehicle speed is 0, the actual deviation is directly integrated by 1-, so this prevention effect is further strengthened. FIG. 10 shows changes in the rotational position of the step motor 110 (i.e. speed ratio), the engine rotational speed, and the values of θs, P, and I when such a situation occurs. This will tell you whether the gear ratio has changed or is being relaxed. This becomes clearer when compared with the conventional example shown in FIG. 11 (without steps 913, 915, 927 and 929 in FIGS. 7 and 8).

Note that in a normal state in which the signal indicating the vehicle speed is not 0, the following effects are obtained. 1-In other words, if the absolute value of the deviation e is smaller than C4 and C2, the value of Dpi is the sum of the value proportional to the deviation e (P) and the integral value corresponding to the deviation (I) as usual. This becomes the feedback control amount. Further, when C,>C2, only the integral value corresponding portion changes between C2 and C, and the deviation corresponding portion becomes a constant value. Furthermore, when the absolute value of the deviation e becomes larger than 01, the value of ■ is reset and its addition is stopped. As a result, even if a very large deviation occurs, the target step motor position ND or N is larger than necessary.
is not commanded, overshoot during gear shifting is prevented, the rotational speed changes smoothly during gear shifting, and shock is reduced.

(g) As described in detail, according to the present invention, when the signal indicating the vehicle speed becomes 0, feedback control using the integral value of the deviation is activated, so feedforward control is performed. It can compensate for changes in position and prevent sudden engine braking and engine overrun.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the constituent elements of the present invention. Figure 2 is a sectional view of a V-belt continuously variable transmission, Figure 3 is a diagram showing the entire control device of the continuously variable transmission, Figure 4 is a diagram showing the speed change control device, and Figure 5 is a force motor control routine. Figure 6 is a diagram showing a complete fastening control routine, Figures 7 to 9 are diagrams showing a complete fastening control routine.
The figure shows the step motor control routine, Figure 10 is a diagram showing the change in extrusion when the vehicle speed sensor fails in this embodiment, and Figure 11 shows the change in explant when the vehicle speed sensor fails in the conventional example. FIG.

Claims (1)

[Scope of Claims] 1. A control device for a continuously variable transmission in which a gear ratio is determined according to the operating position of a gear shift actuator, the control device controlling the gear ratio depending on the operating position of a gear shift actuator, and in which the gear ratio is determined based on the vehicle speed and/or the engine load. feedforward control means for determining a forward control position; target value determining means for determining a target value of the input rotational speed or gear ratio of the continuously variable transmission based on both or either of the vehicle speed and the engine load; A control device for a continuously variable transmission comprising: a deviation calculation means for calculating a deviation between an actual value and a target value of a gear ratio; and an integration means for integrating the deviation calculated by the deviation calculation means. is not 0 and the deviation is larger than a predetermined value, the first control unit resets the integrating means to the initial state, adds a feedback control amount based on the deviation to the feedforward control position, and outputs a speed change command signal to the speed change actuator. a shift command means; when the signal indicating the vehicle speed is 0 or the deviation is smaller than the predetermined value, a feedback control amount based on the deviation and the integral value is added to the feedforward control position, and a shift command signal is output to the shift actuator; 1. A control device for a continuously variable transmission, comprising: second shift command means.