Transmission system with acceleration-compensated valve control and vehicle equipped with it

Abstract

Vehicle (10), comprising: a motor (12); a gearbox (14) which is connected to the motor (12) and which includes the following: a pressure regulating solenoid valve device comprising a pressure regulating solenoid valve (PCS) (26) and a control valve (40) controlled via the PCS (26); a friction clutch (27); and a coupling piston (29) fluidically connected to the control valve (40), wherein the coupling piston (29) serves to exert a coupling pressure on the friction clutch (27); and a control unit (50) connected to the PCS (26), which is programmed for this purpose: to determine an acceleration value that describes at least one lateral and / or longitudinal acceleration force of the vehicle (10); to calculate the clutch pressure using the determined acceleration value in a way that compensates for acceleration-related inertial effects on the control valve (40); and to control the operation of the control valve (40) using the calculated clutch pressure via the PCS (26), thereby automatically compensating for the effects of acceleration on the switching behavior of the control valve (40).

Description

TECHNICAL AREA

[0001] The present invention relates to a transmission system with acceleration-compensated valve control and a vehicle equipped therewith. BACKGROUND

[0002] An automatic transmission's friction clutch is typically engaged via a clutch piston, which is actuated by hydraulic fluid pressure. The hydraulic fluid pressure supplied to a given friction clutch is regulated by a control valve, which in turn can be controlled by a pressure control solenoid (PCS). The clutch pressure is usually calculated by a transmission control module rather than measured directly. For example, the transmission control module might multiply a commanded PCS pressure by a calibrated gain, where the calibrated gain depends on the geometry of the control valve upon which the PCS pressure acts. However, these methods may be suboptimal when gear changes occur during certain driving maneuvers.

[0003] Regarding the further state of the art, reference is made at this point to the publications DE 197 10 460 A1, DE 10 2007 062 147 B4 and DE 10 2009 005 123 A1. SUMMARY

[0004] This document discloses a vehicle comprising an engine, a transmission, and a control unit. The transmission includes a friction clutch and a control valve, which is controlled, for example, by a pressure-regulating solenoid valve assembly (PCS). As used herein, the term PCS valve assembly may include a PCS and a separate control valve, or a direct-acting PCS with an integrated control valve. The hydraulic clutch pressure to the friction clutch is controlled via the control valve, for example, by the operation of the PCS. The pressure characteristics of the PCS are calibrated and recorded, for example, in a pressure-current characteristic comparison table, such that a commanded electrical current to the windings of the PCS corresponds to a commanded PCS pressure from the control unit.The control unit performs steps of a procedure described herein to calculate the clutch pressure in a manner that compensates for inertial effects on the control valve during threshold longitudinal and / or lateral acceleration of the vehicle.

[0005] It should be noted that, due to the mass of the control valve, pressure commands to the clutch during a transmission shift can be temporarily influenced by vehicle acceleration. These performance effects, which may manifest as temporary turbine bulging or coupling depending on the direction and magnitude of the acceleration and the orientation of the control valve, can be clearly perceived by a driver, especially during high acceleration, which can occasionally occur in high-performance vehicles. Therefore, the present approach uses acceleration sensor readings and / or calculated acceleration levels to determine the acceleration forces acting on the control valve and then compensates for these acceleration effects, as described herein, using a compensating pressure.This largely avoids temporary conditions that can adversely affect switching quality due to acceleration.

[0006] According to the invention, a vehicle is proposed in particular, characterized by the features of claim 1. Furthermore, a transmission system is proposed, characterized by the features of claim 4.

[0007] A method for compensating for the effects of acceleration when controlling a control valve of a PCS valve device in a vehicle with a transmission involves using a control unit to determine an acceleration value that describes at least the lateral and longitudinal acceleration of the vehicle. The method also includes calculating the clutch pressure via the control unit using the received acceleration value, as well as controlling the operation of a PCS during the transmission shifting process using the calculated clutch pressure.

[0008] The aforementioned features and advantages, as well as further features and advantages of the present disclosure, will become clear from the following detailed description of some of the preferred and further embodiments of the present disclosure, as defined in the attached claims, taking into account the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic representation of a vehicle with a gearbox and clutch, a pressure control solenoid valve device (PCS) with a PCS and a control valve, and a control unit programmed to control the PCS in an acceleration-compensated manner via a method described herein. Fig. Figure 2 is a schematic representation of part of a control valve and a control unit, which is part of the gearbox in Fig. 1 can be used. Fig. Figure 3 is a flowchart illustrating a method for acceleration-compensated control of a PCS in a PCS valve device from the Fig. 1 and Fig. 2 describes. DETAILED DESCRIPTION

[0009] Referring to the drawings, in which the same reference symbols refer to the same components in the different figures, it is stated in Fig. Figure 1 shows a schematic representation of an exemplary vehicle 10 with a chassis 10C. The vehicle 10 includes an internal combustion engine (E) 12, a transmission (T) 14 connected to the engine 12, and a control unit (C) 50. The transmission 14 includes a clutch assembly 25, which is fluidically connected to a pump 22 that draws fluid from a sump 21. An additional structure of the transmission 14, which is omitted for illustrative purposes, may include one or more gear sets with transmission elements such as a ring gear, sun gear, and support element. The clutch assembly 25, which is also shown schematically for illustrative purposes, includes a pressure-regulating solenoid valve device (PCS) 26D, i.e., a duty-cycle-controlled device which, as is well known in the field, manages the pressure in the transmission 14.The term “PCS valve device,” as used herein, can include a PCS 26 and a separate control valve 40, or a direct-acting PCS 26 with an integral control valve 40; that is, the PCS 26 and the control valve 40 can be integrated into one device. The coupling circuit 25 further includes a control valve 40 controlled by the PCS 26, a friction coupling 27, and a coupling piston 29 fluidically connected to the control valve 40. The coupling piston 29 actuates the friction coupling 27 in response to pressure commands from the control unit 50 (arrow P). PCS ) to the PCS 26 with a clutch pressure (arrow Pc) during a shift of the gearbox 14.

[0010] The control unit 50, which is connected to the PCS 26 and serves to change an electrical current supplied to the coils or windings of the PCS 26 in order to generate a PCS pressure (arrow P) PCSThe control unit 50, which is specifically programmed to compensate for the inertial effects acting on the known mass of the control valve 40 during the overall control of a shifting operation of the transmission 14, particularly during aggressive acceleration maneuvers, is designed to change the position of the control valve 40, as is known in the field. To achieve the desired results, the control unit 50 is programmed to adjust one or more acceleration values ​​(arrows A). X , A Y ) to determine, i.e. to receive or calculate, which describe a lateral and / or longitudinal acceleration value with respect to corresponding lateral and longitudinal axes X, Y of the vehicle 10.

[0011] Additionally, the programming of the control unit 50 allows this control unit 50 to selectively adjust the clutch pressure (arrow Pc) using the determined acceleration values ​​A. X and / or A Yto calculate and control the operation of the control valve 40 during the shifting process of the transmission 14 using the calculated clutch pressure (arrow Pc) according to procedure 100. A simplified example control valve 40 is described below with reference to Fig. 2 described, with reference to Fig. 3 an example of procedure 100 is described in more detail.

[0012] With reference to example vehicle 10 of the Fig. 1 In response to the throttle movement, e.g. by an accelerator pedal (not shown), the motor 12 delivers an input torque (arrow T) via a crankshaft 13, for example via an input clutch CI or a hydrodynamic torque converter arrangement. I ) to an input element 15 of the gearbox 14. The gearbox 14 transmits the input torque (arrow T). I ) through various gear sets (not shown) of the gearbox 14, so that ultimately an output torque (arrow T) O) via a multitude of friction clutches, of which only one, i.e. friction clutch 27, is used for illustration in Fig. As shown in Figure 1, the signal is transferred to an input element 18 and from the output element 18 to one or more drive axles 19 and drive wheels 20. The drive wheels 20 can be front and / or rear wheels 20 in various embodiments, which is why the rear wheel configuration of Fig. Figure 1 is for illustrative purposes only and not intended as a limitation. A typical multi-stage embodiment of the transmission 14 would comprise several planetary gear sets connected to one another via various rotary or braking friction clutches, each friction clutch being controlled by a corresponding control valve 40. The control of said clutches by the control unit 50 ultimately transmits the drive torque (arrow T). I) through the gearbox 14 at a specific gear ratio to achieve the output torque (arrow T) O to generate.

[0013] The control unit is programmed according to the steps of a procedure 100 to execute computer code. The control unit 50 can be configured as a digital computer with a processor (P) and a memory (M). The memory (M) includes sufficient physical, non-transient storage space, such as ROM, flash memory, magnetic or optical storage, electronically programmable ROM, and the like. The memory (M) also includes sufficient transient storage, such as random-access memory or electronic buffer memory. The hardware of the control unit 50 includes a high clock frequency, an analog-to-digital and a digital-to-analog circuit, an input / output circuit and devices, as well as corresponding signal conditioning and buffer circuits.

[0014] In one possible embodiment, the vehicle can consist of 10 Fig. 1 one or more acceleration sensors, for example, a first and second acceleration sensor S connected to the control unit 50 X and S Y include. Each accelerometer S X , S Y It serves to measure a corresponding acceleration value for a given axis X or Y. For example, the first and second acceleration sensors can be arranged relative to the vehicle 10, e.g., on the chassis 10C or in the transmission 14. The first and second acceleration sensors S X and S YThese are used to measure the lateral and longitudinal acceleration of the vehicle 10, where the terms "lateral" and "longitudinal" indicate the axial direction of the measurement with respect to the lateral and longitudinal axes X and Y of the vehicle 10 and the transmission 14, respectively. Thus, the control unit 50 can, within the framework of the procedure 100, measure one or more acceleration values ​​(arrows A). X , A Y ) received. Alternatively, the control unit 50 can receive the acceleration value(s) (arrows A). X , A Y ) using the velocity (arrow N) 10 ) and the steering angle (θ 10 ) of the vehicle 10, which are measured, for example, via a corresponding speed sensor and steering angle sensor (not shown).

[0015] With brief reference to Fig. 2 the control unit 50 with the control valve 40 and a nozzle section 26N of the PCS 26 from Fig. Figure 1 shows the control valve 40 having disc-shaped first and second spool ends 42 and 44 for the respective main and secondary surface areas A1 and A2. A solenoid valve control current flows from the control unit 50 to the coils of the PCS 26. Fig. 1 ultimately causes the PCS print (arrow P) PCS The fluid can be supplied through the nozzle section 26N to the first end 42 of the control valve 40, thereby displacing the control valve 40 to compress a pre-tensioned return spring (RS). The nozzle section 26N also acts as a mechanical stop for the control valve 40, thus preventing overrun of the control valve 40.

[0016] A valve body 32 surrounding the control valve 40 defines a plurality of fluid channels, the identity of which depends on the design of the control valve 40. In the simplified example of Fig. 2. The valve body 32 can have an exhaust gas channel 33 for absorbing exhaust gas pressure (arrow P). EX ), a clutch supply channel 34 for applying clutch pressure to the clutch 27 (arrow Pc), a line pressure channel 35 for receiving line pressure (arrow P L ) from pump 22, as well as a pressure return channel 36 for receiving the feedback pressure (arrow P) FB ) from other points in the coupling circuit 25 to enable the control valve 40 to perform its pressure regulating function, as is known in the field. The line pressure (arrow P) L The pressure from pump 22 is fed to the control valve 40 via the line pressure channel 35 and, depending on the commanded PCS pressure (arrow P), PCS ) supplied to the clutch as part of the clutch pressure (arrow Pc).

[0017] The control unit 50 of the Fig. 1 and Fig. As mentioned above, unit 2 is specifically programmed to calculate the clutch pressure (arrow Pc) during vehicle operation 10 as a function of the vehicle's acceleration 10. Thus, control unit 50 determines the acceleration values ​​(arrow A). X , A Y ) and automatically compensates for the effects of acceleration on the switching behavior of the control valve 40 while it is controlled by the PCS 26. In general, the control unit 50 calculates the clutch force (Fc) using the following force equilibrium equation: FC=(FPCS−FS−FFB+FA)G where G corresponds to the amplification factor, i.e. the ratio A1 / A2, F PCS corresponding to the force applied by the PCS 26, F S the force of the return spring (RS) corresponds to F FB the feedback force through the fluid channel 36 corresponds to, and F AThis corresponds to the force acting on the control valve 40 as a result of the acceleration. As is known in the field, F = ma, where the mass (m) of the control valve 40 is a known quantity, so that the acceleration forces (ẍ) acting on the control valve 40 can be readily calculated.

[0018] More precisely, the control unit 50 can calculate the clutch force as follows: FC=(A1)(PPCS)−(Kx+FPL)−mx¨A2 where K corresponds to the spring constant of the return spring (RS), x corresponds to the linear displacement of the control valve 40, F PL The preload force of the return spring (RS) corresponds to m, the mass of the control valve 40 to m, and ẍ, as mentioned above, to the acceleration value. In this equation, the equalization pressure of the control valve 40 can be defined as follows: Kx+FPLA2 which could be programmed into a lookup table for a corresponding acceleration value, so that the control unit 50 can selectively extract a compensating pressure value for each given acceleration and apply it in the calculation of the clutch pressure (arrow Pc) to control a position or other operation of the control valve 40 in such a way as to compensate for the effects of the acceleration on the control valve 40.

[0019] When installed in the transmission 14, the control valve 40 has a predetermined axial orientation with respect to a transverse or longitudinal axis X and Y of the vehicle 10. Therefore, the control unit 50 can be programmed to adjust the lateral or longitudinal acceleration values ​​(arrows A). X , A Y ) based on the predetermined orientation of the control valve 40. For example, if the control valve 40 is oriented according to Fig. 2 is arranged longitudinally or parallel to the longitudinal axis Y of the vehicle 10, the longitudinal acceleration value (arrow A) can be Y ) in the formulas above. Likewise, if the control valve 40 is arranged longitudinally or parallel to the transverse axis X of the vehicle 10, the lateral acceleration value (arrow A) can be used. X ) in the formulas above. In other embodiments, where the control valve 40 is arranged along any other axis, a vector can be used depending on the transverse and longitudinal acceleration values ​​(arrows A). X , A Y ) calculated and used in the above equations without deviating from the intended scope of the invention.

[0020] With reference to Fig. Figure 3 begins an exemplary embodiment of the method 100 with step S102, in which the control unit determines whether a shift operation of the transmission 14 is requested in the logic of the control unit 50. That is, the control unit 50 evaluates typical shift control parameters, such as the speed of the engine 12, the input element 15 and / or the output element 18, the throttle request, the brake stages, the current gear ratio, etc., and determines whether a shift operation to a different gear state is required. The method proceeds to step S104 if the shift operation is requested.

[0021] In step S104, the control unit 50 determines the acceleration value(s) (arrows A). X , A Y ) of the vehicle 10. When determining the acceleration value(s) (arrows A X , A Y) the control unit 50 can process the measured accelerations from the acceleration sensors S X , S Y out of Fig. 1 received and / or the control unit 50 can receive the acceleration values ​​(arrows A) X , A Y ) calculate. Procedure 100 proceeds to step S106 when the acceleration value(s) (arrows A) X , A Y ) received or otherwise become known.

[0022] Step S106 may include access to a lookup table indexed by acceleration forces and the compensating pressure disclosed above. As an illustrative example, the lookup table may contain a value corresponding to the PCS pressure (arrow P). PCS ) add a compensating pressure to ultimately reduce the clutch pressure (arrow P) C) to influence performance when the acceleration forces exceed ± 0.2 G or another relatively low threshold. Above this threshold, the control unit 50 can apply a compensating pressure, e.g., linearly increasing in one or more stages or with one or more increments from 0 at +0.1 G up to a calibrated maximum compensating pressure at a calibrated maximum acceleration force of, e.g., ± 1.5 G, and then compensate so that the acceleration forces exceeding the calibrated maximum acceleration force receive the calibrated maximum compensating pressure. Since acceleration forces can affect performance in different ways depending on their magnitude, some embodiments may employ more aggressive compensation for higher acceleration relative to lower acceleration, effectively matching the compensation performance to the severity of the acceleration event.Procedure 100 then proceeds to step S108.

[0023] In step S108, the control unit 50 controls the shifting of the gearbox 14 using the PCS pressure calculated in step S106 (P PCS This means that the set PCS pressure (P PCS ) determining the new clutch pressure (arrow P) C ) enables the control unit 50 to achieve a required position of the control valve 40, i.e., the linear displacement of the control valve 40 by changing the PCS pressure command (arrow P) PCS ) can control. This results in a change to an electrical current command to the PCS 26, which regulates the pressure on the control valve 40 and ultimately changes or maintains the required clutch pressure (arrow Pc).

[0024] Since acceleration-induced transient states, such as turbine bulging or coupling, can be observed in the presence of certain acceleration forces for a given vehicle, experts in the field will recognize, in light of this disclosure, that the compensating pressure for each control valve 40 in a given vehicle 10 is calibratable to reduce or eliminate instances of turbine bulging or coupling. That is to say, the values ​​used to compensate for the acceleration forces can be determined for a given vehicle 10, stored in the memory (M) of the control unit 50, and subsequently used to control the operation of all control valves 40 that serve to control a given shift operation of the transmission 14.Therefore, the use of acceleration data can optionally be applied to a given control valve 40 in a manner that is tailored to the orientation of the control valve 40 within the vehicle and is based on the effects of acceleration on the performance of a particular control valve 40 for the given shifting operation, thereby improving the overall shifting quality.

Claims

[1] Vehicle (10), comprising: an engine (12); a gearbox (14) connected to the engine (12), which includes: a pressure control solenoid valve device comprising a pressure control solenoid valve (PCS) (26) and a control valve (40) controlled by the PCS (26); a friction clutch (27); and a clutch piston (29) fluidly connected to the control valve (40), the clutch piston (29) serving to exert a clutch pressure on the friction clutch (27); and a control unit (50) connected to the PCS (26) and programmed to: to determine an acceleration value which describes at least one lateral and / or longitudinal acceleration force of the vehicle (10); to calculate the clutch pressure using the determined acceleration value in a manner that compensates for acceleration-related inertial effects on the control valve (40); and to control operation of the control valve (40) using the calculated clutch pressure via the PCS (26), whereby effects of acceleration on the switching behavior of the control valve (40) are automatically compensated. [2] The vehicle (10) according to claim 1 further comprises an acceleration sensor (S X , S Y ) which serves to measure the acceleration value, wherein the control unit (50) is programmed to determine the acceleration value by receiving the measured acceleration value from the acceleration sensor. [3] Vehicle (10) according to claim 2, wherein the acceleration sensor comprises a first acceleration sensor (S X ) for measuring the lateral acceleration force, as well as a second acceleration sensor (S Y ) for measuring the longitudinal acceleration force. [4] Transmission system includes the following: a pressure control solenoid valve device comprising a pressure control solenoid valve (PCS) (26) and a control valve (40) controlled by the PCS (26); a transmission (14) with a friction clutch (27); and a clutch piston (29) fluidly connected to the control valve (40), the clutch piston (29) serving to apply a clutch pressure to the friction clutch (27) during a shifting operation of the transmission (14); and a control unit (50) connected to the control valve (40) and programmed to: to determine an acceleration value which describes at least one lateral and / or longitudinal acceleration force of the vehicle (10); to calculate the clutch pressure using the received acceleration value in a manner that compensates for acceleration-related inertial effects on the control valve (40); and to control operation of the control valve (40) using the calculated clutch pressure via the PCS (26), whereby effects of acceleration on the switching behavior of the control valve (40) are automatically compensated. [5] The transmission system according to claim 4 further comprises an acceleration sensor (S X , S Y ), wherein the control unit (50) is programmed to determine the acceleration value by receiving the measured acceleration value from the acceleration sensor (S X , S Y ) receives. [6] Transmission system according to claim 5, wherein the acceleration sensor (S X , S Y ) a first acceleration sensor (S X ) for measuring the lateral acceleration force, as well as a second acceleration sensor (S Y ) for measuring the longitudinal acceleration force. [7] The transmission system of claim 6, wherein the control valve (40) has a predetermined orientation with respect to a transverse or longitudinal axis of the transmission (14) and the control unit (50) is programmed to use the transverse or longitudinal acceleration force based on the predetermined orientation of the control valve (40). [8] A transmission system according to claim 4, wherein the operation of the control valve (40) corresponds to a position of the control valve (40). [9] A transmission system according to claim 4, wherein the control unit (50) is programmed with a look-up table containing a calibrated compensation pressure of the PCS (26) corresponding to the acceleration value. [10] A transmission system according to claim 4, wherein the control valve (40) has a linear displacement and includes a return spring (RS) and the control unit (50) is programmed to calculate the clutch pressure using surface areas of the control valve (40), a pressure command to the PCS (26), the pressure of the return spring, and the acceleration value.

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