JP2005054864A - Speed change controller for transmission in sensor stationary-state error intermediate correction type - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the control for making a change gear ratio to follow a target change gear ratio from being disturbed by a sensor detecting error like the displacement detection of a trunnion in the speed change control of a transmission like a toroidal type transmission. <P>SOLUTION: A detection value of a displacement sensor is corrected by a stationary-state error of the displacement sensor when a target value of the difference between a disk center axis line and a roller center axis line corresponding to the difference between the target change gear ratio and an actual change gear ratio is compared with the actual measurement value of the difference by the displacement sensor in an example of the toroidal type transmission. The stationary-state error of the displacement sensor is obtained by learning. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transmission control device for a transmission, and more particularly to improving the operating characteristics of a transmission control device incorporating a sensor in the control process.

  As one of the transmissions suitable for a vehicle transmission or the like, a pair of disks having an operation surface whose radius changes along an axis line, and the operation surfaces of the pair of disks are held between coaxially facing each other. And transmitting a rotational force between the pair of disks via the plurality of rollers, and transmitting between the pair of disks by changing the angle of each roller with respect to the pair of disks. 2. Description of the Related Art A disk / roller type continuously variable transmission configured to continuously change a transmission gear ratio of a rotating force is known. Since the operating surface of the disk of such a disk / roller type continuously variable transmission is generally formed as a part of the toroidal surface, such a continuously variable transmission is usually called a toroidal type continuously variable transmission.

In the toroidal type continuously variable transmission as described above, a shift control valve such as the shift control valve 112 described above is provided for each trunnion in order to enhance the synchronism of the operation of the hydraulic actuator with respect to each of the plurality of trunnions in the shift control. It is described in the following Patent Document 1 that each is provided individually. Also, in controlling the gear ratio, the target gear ratio is calculated and the deviation between the target gear ratio and the actual gear ratio is detected, while the input torque is calculated and the input torque exceeds the predetermined threshold value. Patent Document 2 below describes that whether or not the input torque exceeds the threshold value, the deviation is learned and the gear ratio is corrected in accordance with the learned value. Yes.
JP 2000-257686A JP-A-8-338492

  In the disk / roller type continuously variable transmission as described above, when it is kept constant at an arbitrary gear ratio, the plurality of rollers are in a state where their center axis intersects the center axis of the pair of disks. When the ratio is to be changed, only during the change, the plurality of rollers are displaced so that the central axis is removed from either intersection with the central axis of the pair of disks to one side in accordance with acceleration or deceleration. The In this case, in order for the transmission to operate stably at an arbitrary gear ratio, it is necessary to accurately detect the displacement 0 by the displacement sensor, otherwise the transmission can be operated at any gear ratio. There is a risk that it will not be able to operate stably.

  However, the displacement of the trunnion in a disc / roller type continuously variable transmission used in an actual vehicle or the like is usually about 1 mm at most, and in order to increase the detection accuracy, the displacement sensor has a correspondingly high cost. Cost. In addition, the trunnion is a device that always operates under the action of a high mechanical load, and in view of the magnitude of mechanical stress that acts on each part of the transmission during its operation, the accuracy of the displacement sensor is long with the initial setting. There is considerable difficulty in maintaining over time.

  The present invention deals with a case where an error in detecting a displacement of a roller in the middle of the transmission, particularly a disc / roller type continuously variable transmission, greatly affects the stability of the control. It is an object of the present invention to provide a shift control device that can solve the problem.

  In order to solve such a problem, the present invention provides a transmission control device that controls a transmission gear ratio to a target gear ratio, and provides an intermediate control amount corresponding to the difference between the target gear ratio and the realized gear ratio. Means for determining the target value of the intermediate control amount, and means for controlling the transmission in response to the difference between the target value for the intermediate control amount and the actually measured value by the sensor, and the target value for the intermediate control amount and the sensor The present invention proposes a control device characterized in that when compared with an actual measurement value, the actual measurement value by the sensor is corrected by a steady error of the sensor.

  The transmission includes a pair of discs having an operating surface whose radius changes along an axis, and a plurality of rollers pressed between the operating surfaces of the pair of discs coaxially opposed to each other, A rotational force is transmitted between the pair of disks via a plurality of rollers, and the center axes of the rollers are displaced with respect to the center axes of the pair of disks, thereby tilting the rollers with respect to the pair of disks. Is a disk / roller type continuously variable transmission configured to change the transmission gear ratio of the rotational force transmitted between the pair of disks, and the intermediate control amount is calculated based on the roller center axis relative to the disk center axis. It may be a displacement amount.

  Further, the shift control apparatus as described above may learn the steady-state error of the sensor as needed. In this case, the displacement detected by the sensor when the actual gear ratio approaches the target gear ratio within a predetermined deviation may be the steady error of the sensor.

  In addition, the speed change control device newly updates the steady-state error when the absolute value of the difference between the steady-state error newly detected for the displacement sensor and the steady-state error that has been employed exceeds a predetermined limit value. It may be replaced with a value detected in (1).

  As described above, the speed change control device for controlling the speed ratio of the transmission to the target speed ratio includes a means for determining a target value of one intermediate control amount corresponding to the difference between the target speed ratio and the realized speed ratio, When having a means for controlling the transmission corresponding to the difference between the target value for the intermediate control amount and the actually measured value by the sensor, when comparing the target value for the intermediate control amount with the actually measured value by the sensor If the measured value by the sensor is corrected by the steady error of the sensor, the control error due to the steady error of the sensor can be effectively eliminated at an early stage of control, and the speed change control can be performed quickly. And improved stability.

  The correction of the sensor steady state error in the intermediate control stage as described above is performed particularly when the transmission has a pair of disks each having an operating surface whose radius changes along the axis, and the operating surfaces of the pair of disks face each other coaxially. A plurality of rollers sandwiched between the plurality of rollers, and transmitting a rotational force between the pair of disks via the plurality of rollers, wherein the center of each of the rollers with respect to the central axis of the pair of disks A disc / roller type continuously variable transmission configured to cause the respective rollers to tilt with respect to the pair of discs by displacing an axis, thereby changing a gear ratio of a rotational force transmitted between the pair of discs. When the intermediate control amount is the amount of displacement of the roller center axis with respect to the disk center axis, the disk center axis and the disk center axis that influence the shift behavior of the transmission directly and physically affect each other. The target value and the actual value related to the deviation between the center axes can be compared without being confused by the measurement error of the displacement sensor, and the convergence of the feedback control of the gear ratio to the target gear ratio can be greatly increased. it can.

  Moreover, if the steady-state error of the displacement sensor is obtained by learning as needed, the accuracy of the steady-state sensor error can be increased.

  In this case, in the process of controlling the transmission gear ratio to the target transmission gear ratio, when the transmission gear ratio approaches the target transmission gear ratio within a predetermined deviation, the displacement detected by the displacement sensor is set as a steady error of the displacement sensor. By doing so, the steady-state error of the displacement sensor can be estimated with reasonable accuracy.

  At that time, when the absolute value of the difference between the newly detected steady-state error and the steady-state error used so far exceeds a predetermined limit value, the steady-state error is replaced with the newly detected value. In this way, even if the steady-state error of the displacement sensor changes due to deformation of the transmission mechanism due to torque input, temperature change, aging of the transmission itself, etc., the steady-state error can be corrected following the change.

  FIG. 1 attached herewith is a schematic diagram showing an example in which the present invention is implemented in an automatic transmission drive system of a vehicle using a disc / roller type continuously variable transmission. In a disk / roller type continuously variable transmission, as is generally done in the case of a vehicle drive device, two sets of disk / roller type continuously variable transmissions are composed of a first set of output side disks and a second set of disks. A pair of output side disks are coaxially arranged back-to-back, and first and second sets of input side disks are coaxially arranged on both sides of the first and second sets of output side disks. The first and second sets of input side disks are connected to each other in a torque transmission relationship by a connecting shaft that passes through the first and second sets of output side disks.

  That is, in FIG. 1, 10a, 10b, 10c, and 10d are disks having working surfaces whose radii change along the axis, and these working surfaces 12a, 12b, 12c, and 12d are concave toroidal surfaces. Is formed. The disks 10a, 10b, 10c and 10d are arranged in alignment with a common central axis n. The disks 10a and 10b constitute a pair of disk / roller type continuously variable transmissions together with a pair of rollers 14a and 14b, and the disks 10c and 10d constitute another pair of disks / rollers together with another pair of rollers 14c and 14d. A type continuously variable transmission is configured. In the disk / roller type continuously variable transmission constituted by the disks 10a and 10b and the rollers 14a and 14b, the disk 10a is the input side and the disk 10b is the output side.

  On the other hand, in the disk / roller type continuously variable transmission constituted by the disks 10c and 10d and the rollers 14c and 14d, the disk 10d is the input side and the disk 10c is the output side. These sets of output side disks 10b and 10c are arranged coaxially back to back along the central axis n, and are connected in a torque transmission relationship with the gear 16 by a spline or the like not shown in the figure. These gears constitute an output member of the disk / roller type continuously variable transmission. Gears 16 and 18 are rotatably supported from the housing of the transmission by bearing means 20, 22 shown diagrammatically in the figure.

  The input side disks 10a and 10d arranged coaxially along the axis n are connected to each other in a torque transmitting relationship by a connecting shaft 24 that passes through the output side disks 10b and 10c, and are connected by a loading cam type pressing means 26. They are combined in a relationship of being drawn along the central axis n through the shaft. That is, the right end of the connecting shaft 24 in the drawing is connected to the disk 10a in a torque transmitting relationship and fixed to each other in the axial direction by the spline 28, the nut 30, and the like. In this case, the disk 10 d is rotatably supported on the connecting shaft 24 by the bearing 32. The connecting shaft 24 is rigidly connected to the disc member 34. Annular cams 36 and 38 are respectively formed at the peripheral edges of the disk 10d and the disk member 34 facing each other, and a plurality of rollers 40 spaced apart in the circumferential direction are provided therebetween. . With this configuration, when a torque acts between the connecting shaft 24 and the disk member 34 rigidly connected to the connecting shaft 24 and the disk 10d to cause a relative rotation between the disk member 34 and the disk 10d, even a slight rotation occurs. The roller 40 is engaged between the inclined surfaces of the annular cams 36 and 38, and the disk 10d is connected to the connecting shaft 24 in a torque transmitting relationship, and the disk 10c and the disk 10d are subjected to a reaction acting through the connecting shaft 24. The rollers 14c and 14d and the rollers 14a and 14b are pressed against each other and between the disk 10a and the disk 10b.

  The rotation input is introduced from the input shaft 42 to the disk member 44, and the claw provided on the side opposite to the annular cam 38 of the disk member 34 engaged with the claw 46 provided on the peripheral edge of the disk member. It is transmitted to the disk member 34 via 48.

  The input shaft 42 is connected to the sun gear 52 of the planetary gear device 50. A plurality of planetary pinions 54 are meshed around the sun gear 52 and are carried by a carrier 56. The carrier 56 is selectively fixed to the housing 60 by a brake 58 so that its rotation is braked. A ring gear 62 is meshed around the planetary pinion 54, and this ring gear is connected to an output shaft 68 of the torque converter 66 by a rotating frame 64. The rotating frame 64 and the sun gear 52 are selectively connected by a clutch 70. The torque converter 66 includes a pump 72, a turbine 74, and a stator 76. The pump 72 is connected to a crankshaft 82 of an engine 80 via a rotating frame 78, and the turbine 74 is connected to an output shaft 68 via a buffer joint 84. The stator 76 is supported from the housing 60 via a one-way clutch 86. The torque converter 66 is bypassed by a direct coupling clutch 88.

  Each of the rollers 14a to 14d is supported by a trunnion 94 via an eccentric shaft 90 and a radial / thrust bearing 92 as shown in the section B-B for the roller 14a. The trunnion 94 is a pair for the rollers 14a and 14b and a pair for the rollers 14c and 14d, and is combined with each other by links 96 and 98 at positions above and below the roller support portion. The bearings 100 and 102 are supported at the engaging portion with the link so as to be rotatable around the longitudinal central axis s. The lower end of the trunnion is connected to the piston 106 of the hydraulic actuator 104, and the hydraulic oil is supplied to and discharged from the hydraulic chambers 108 and 110 formed below and above the piston so that the trunnion is displaced in the vertical direction. ing. The vertical displacement of the trunnion 94 by the hydraulic actuator 104 is detected by a displacement sensor 111 connected to the lower end of the trunnion. The lower hydraulic chamber 108 and the upper hydraulic chamber 110 are connected to the ports 114 and 116 of the transmission control valve 112 through oil passages U and D, respectively.

  The speed change control valve 112 is in the state of “a” when neither solenoid is energized according to the status of energization of the solenoids 118 and 120, and when the energization is performed only on the solenoid 118, This is a 4-port linear control valve that is controlled so that it is in the state c when the solenoid 120 is energized only. Pressure oil is supplied to a port 122 of the speed change control valve 112 from a pressure oil source 124 such as a hydraulic pump, and a port 126 is an oil discharge port toward the oil reservoir 128.

  The solenoids 118 and 120 of the speed change control valve 112 are selectively energized in response to a command from the electronic vehicle operation control device 130. The electronic vehicle operation control device 130 is well known in the field of this technology equipped with a microcomputer, performs control calculation based on various input information I and information on trunnion displacement from the displacement sensor 111, In addition to the shift control valve 112, the engine 80, the direct coupling clutch 88, the clutch 70 and the brake 58 are controlled.

  The toroidal-type continuously variable transmission having the above-described configuration is speed-controlled by a control circuit as shown in FIG. That is, now when the target value of the gear ratio is designated as φc, the difference Δφ between the target gear ratio φc and the actual gear ratio φ is proportionally processed on the one hand with the proportional coefficient Kap, and on the other hand Integration processing is performed (1 / s), and further proportional processing is performed by proportional processing with a proportional coefficient Kai, so that a trunnion target offset yc corresponding to Δφ is calculated. Next, the target offset yc is compared with the actual offset y, and the deviation Δy between the target offset yc is proportionally processed with an appropriate correction coefficient Kop, and further becomes the trunnion offset y through the hydraulic means having the transfer function Gc (s). . The trunnion offset y is converted into the transmission gear ratio φ by the transfer function Gr (s) of the toroidal-type continuously variable transmission, the generated transmission gear ratio φ is compared with the target transmission gear ratio φc, and the deviation is converged toward zero. Control is performed.

  Further, according to the present invention, the trunnion offset y detects the displacement of the trunnion before it is compared with the target trunnion offset yc calculated based on the difference between the target speed ratio φc and the actual speed ratio φ. Is corrected by the steady-state error εsc inherent to Thus, before the offset detection value in the trunnion displacement sensor is compared with the target trunnion offset yc calculated based on the difference between the target gear ratio φc and the actual gear ratio φ, the steady state existing in the displacement sensor itself. By correcting the error, it is possible to prevent convergence delay and hunting due to the error in feedback shift control of the disk / roller type continuously variable transmission. Further, the steady-state error of the displacement sensor may change over time due to deformation of the transmission mechanism due to torque input, temperature change, and change over time in the trunnion support structure of the disc / roller type continuously variable transmission. However, in this regard, if the correction is always made by learning as described above, the correction function is maintained regardless of such a change with time.

  FIG. 3 is a flow chart illustrating one embodiment in the form of its mode of operation when the invention described above with reference to FIGS. 1 and 2 is implemented. The operation of the speed change control device according to this flowchart is performed by incorporating a control program into the electronic vehicle operation control device 130 in software. In this case, the process related to the steady state error of the sensor relates to the displacement sensor 111.

  The operation of the speed change control device according to the present invention is performed as part of overall vehicle operation control by the electronic vehicle operation control device 130. When control is started, in step 1, reading of signals relating to parameters related to the present invention is performed as part of reading of all other signals. Next, the control proceeds to step 2, and it is determined whether or not a condition for performing learning for estimating the steady state deviation of the trunnion displacement sensor 111 is established. Such learning conditions may include the oil temperature, the vehicle speed, the accelerator opening, the rate of change thereof, etc. in the shift control system. It may be said that. If the answer is yes, control proceeds to step 3. When the answer is no, the control of this time is finished as it is, but at that time, the steady-state deviation of the displacement sensor is maintained at the value learned and adopted before that time. The control according to this flowchart is repeatedly executed at an appropriate cycle.

  In step 3, the target speed ratio φc is temporarily fixed to a predetermined value φct. The predetermined value φct is a gear ratio that differs from the gear ratio at the time point when it is determined that the learning condition is satisfied by an appropriate difference.

  Next, the control proceeds to step 4 where gear ratio control is performed by PI control of the gear ratio difference Δφ and P control of the trunnion offset Δy with the gear ratio φct as the target gear ratio. In this case, the trunnion offset y is corrected by the steady-state error εsc of the displacement sensor 111 calculated in step 6 below before being compared with yc to be ym (= y−εsc). (In the first control when εsc is not yet calculated, εsc may be 0 or an initial value of an appropriate size.)

  Next, the control proceeds to step 5, and it is determined whether or not the transmission gear ratio φ has approached the target transmission gear ratio φct within a difference εr set to an appropriately small value. Initially, the answer is of course no. While the answer to step 5 is no, the control returns to step 4 and the control for changing the gear ratio to the target gear ratio φct is continued.

  As the gear ratio change control proceeds, the answer to step 5 will eventually turn from no to yes. If the answer to step 5 is yes, the control proceeds to step 6, and εs, which is the difference between yc and y at that time, is obtained as a steady-state error of the trunnion.

  Next, the control proceeds to step 7, and it is determined whether or not the currently calculated steady-state error εs of the trunnion is different from the currently used steady-state error εsc by a certain small value δε. When the answer is no, the trunnion steady-state error εsc is left as it is. However, when the answer is yes, the control proceeds to step 8, and the trunnion steady-state error εsc is changed to the newly calculated value of εs. .

  While the present invention has been described in detail with respect to one embodiment thereof, it will be apparent to those skilled in the art that various modifications can be made within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Schematic which shows an example which applied the disc / roller type continuously variable transmission to the automatic transmission drive system of a vehicle in order to implement this invention. FIG. 2 is a control circuit diagram of the disk / roller type continuously variable transmission shown in FIG. 1. 1 is a flowchart showing an embodiment of a shift control device for a transmission according to the present invention in one embodiment in the case of shift control of a disk / roller type continuously variable transmission.

Explanation of symbols

  10a, 10b, 10c, 10d ... disk, 12a, 12b, 12c, 12d ... working surface, 14a, 14b, 14c, 14d ... roller, 16, 18 ... gear, 20, 22 ... bearing means, 24 ... connecting shaft, 26 ... Loading cam type pressing means, 28 ... Spline, 30 ... Nut, 32 ... Bearing, 34 ... Disk member, 36, 38 ... Annular cam, 40 ... Roller, 42 ... Input shaft, 44 ... Disc, 46, 48 ... Claw, 50 ... Planetary gear device, 52 ... Sun gear, 54 ... Planetary pinion, 56 ... Carrier, 58 ... Brake, 60 ... Housing, 62 ... Ring gear, 64 ... Rotating frame, 66 ... Torque converter, 68 ... Output shaft, 70 ... Clutch, 72 ... pump, 74 ... turbine, 76 ... stator, 78 ... rotating frame, 80 ... engine, 82 ... crankshaft, 84 ... buffer joint, 86 ... one-way clutch, 88 ... Direct coupling clutch, 90 ... Eccentric shaft, 92 ... Radial / thrust bearing, 94 ... Trunnion, 96,98 ... Link, 100,102 ... Bearing, 104 ... Hydraulic actuator, 106 ... Piston, 108,110 ... Hydraulic chamber, 111 ... Displacement sensor, 112 ... Shift control valve, 114, 116 ... Port, 118, 120 ... Solenoid, 122 ... Port, 124 ... Pressure oil source, 126 ... Port, 128 ... Oil reservoir, 130 ... Electronic vehicle operation control device

Claims (5)

  Means for determining a target value of one intermediate control amount corresponding to a difference between the target speed ratio and the realized speed ratio, wherein the intermediate control amount is a speed change control device that controls the speed ratio of the transmission to the target speed ratio; Means for controlling the transmission in response to the difference between the target value for the sensor and the actual value measured by the sensor, and when comparing the target value for the intermediate control amount with the actual value measured by the sensor, A control device which is adapted to correct by a steady error of the sensor.   The transmission includes a pair of discs having an operating surface whose radius changes along an axis, and a plurality of rollers pressed between the operating surfaces of the pair of discs coaxially opposed to each other, A rotational force is transmitted between the pair of disks via a plurality of rollers, and the center axes of the rollers are displaced with respect to the center axes of the pair of disks, thereby tilting the rollers with respect to the pair of disks. Is a disk / roller type continuously variable transmission configured to change the transmission gear ratio of the rotational force transmitted between the pair of disks, and the intermediate control amount is calculated based on the roller center axis relative to the disk center axis. The shift control device according to claim 1, wherein the shift control device is a displacement amount.   The shift control apparatus according to claim 1 or 2, wherein a steady-state error of the sensor is learned as needed.   The displacement detected by the sensor when the actual gear ratio approaches the target gear ratio within a predetermined deviation is set as the steady-state error of the sensor. Shift control device. When the absolute value of the difference between the steady-state error newly detected for the sensor and the steady-state error used so far exceeds a predetermined limit value, the steady-state error is replaced with a newly detected value. The shift control apparatus according to claim 3 or 4, characterized in that:

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