WO2008098845A1

WO2008098845A1 - Shifting strategy for transmissions

Info

Publication number: WO2008098845A1
Application number: PCT/EP2008/051216
Authority: WO
Inventors: Oliver Gerundt; Thomas Winter; Ulrich Kappenstein; Carolin Scholler
Original assignee: Robert Bosch Gmbh
Priority date: 2007-02-14
Filing date: 2008-01-31
Publication date: 2008-08-21
Also published as: DE102007006996A1

Abstract

The invention relates to a method for performing shifting operations in automatic transmissions (42) using at least one clutch (44) for motor vehicles. The shifting operations are triggered by a transmission controller (58). An acceleration value (54, 56), which corresponds to the acceleration of the vehicle, is detected. During a shifting operation in the automatic transmission (42), the deviation of a target course (10) of the acceleration of the vehicle from the actual course (20, 30) of the acceleration of the vehicle is reduced to a minimum (31). Subsequent shifting operations are adapted with respect to the minimum (31) of the deviation from the target value (10) of the acceleration.

Description

description

title

Shift strategy for transmissions

State of the art

In automatically shifting transmissions, such as torque converter machines, automated manual transmissions, dual clutch transmissions and the like, which are used on motor vehicles, it is known to reload switching operations on the basis of previous switching operations in order to compensate for aging and wear. In this shift strategy, the shift sequence for subsequent shifts in an automated transmission is changed based on engine speed characteristics and the transmission output shaft of the automated transmission, such as a dual-clutch transmission. The switching strategy known from the prior art is based on the adaptation of switching operations that lie in the future, based on speed curves in the past. It has been found that the adaptation, which is based on speed curves in the past, can be less meaningful and can be associated with predictive errors, since in the future lying, desired by the vehicle or driver driving conditions of the motor vehicle only partially from speed characteristics, that can be derived from the past.

Disclosure of the invention

According to the invention, it is proposed to adapt the switching strategy of an automated transmission on the basis of acceleration sensors present in the vehicle, ie to derive them. The switching result achieved, ie the shifting comfort or the freedom from jerking of a switching operation, can be improved and increased in terms of comfort by installing and evaluating additional acceleration sensors following the solution proposed according to the invention. As acceleration sensors, for example, sensors that are already present in the vehicle, such as acceleration sensors, speed sensors or torque sensors. Furthermore, the acceleration of a motor vehicle can be detected by the sensor system, which is already installed in the motor vehicle as part of an ESP system.

The proposed solution according to the invention already installed in the vehicle acceleration sensors can be used, an additional effort in terms of installation of further, new acceleration sensors can be kept within limits or ideally even avoided. By the proposed solution according to the invention, the comfort of a switching operation, d. H. its jerk freedom, significantly improve and ensure the comfort quality over the life of the motor vehicle. Following the solution proposed according to the invention, further, depending on the wishes of the driver of the motor vehicle, a targeted subjective switching dynamics can be generated.

The comfort improvement with regard to the implementation of switching operations is achieved according to the solution proposed according to the invention in that the deviation of the desired course of the acceleration, which acts on the driver, is reduced to a minimum by the actual course of the acceleration. If the driver of the motor vehicle, for example, does not feel any jerk during an upshift, the acceleration should be kept as constant as possible. In contrast to the known from the prior art adaptation of switching processes based on traversed by the internal combustion engine or an automated transmission speed curves, the measurement of acceleration and / or torque curves is more meaningful. This fact is made use of in the solution proposed according to the invention. The transmission control, which includes both the gear selection and the clutch control, includes, beyond the usual interfaces, additional sensors, such as acceleration sensors. By means of at least one acceleration sensor connected to the transmission control, an angular acceleration can be detected. Furthermore, the change of an angle about the axis of rotation of the automated transmission or a motor-gear unit can be detected via the at least one yaw rate sensor which is assigned to the automated transmission. In a poorly performed shift, it comes to an automated transmission, such as a dual-clutch transmission, which is coupled to the internal combustion engine of a motor vehicle, to a shift shock. The shift shock is perceived by the driver by an acceleration change. Due to the load change that occurs in the mentioned shift shock, a reaction torque is generated on the automated transmission, such as the dual-clutch transmission, which causes a tilting movement of the drive unit, engine and transmission. This tilting movement is intercepted by engine-gearbox bearings. The movement that accompanies the tilting movement of the drive unit, engine and transmission, can be detected on the one hand, that an acceleration measurement is performed in a radius about the Drehpol the movement and on the other hand, a detection of the tilting movement with a rotation rate sensor.

Decisive for the comfort, however, is the acceleration perceived by the driver, which can be detected, for example, on the seat rail on which the driver's seat is received. The measurement of the effect of the acceleration on the driver can be recorded in several ways. Thus, an acceleration measurement can be carried out with a separate accelerometer; alternatively, the acceleration sensor of an ESP system already integrated in the vehicle can be used to record the acceleration. Finally, it is possible that by measuring pins (i-Bolts), which are assigned to the driver's seat and connect the driver's seat with the seat rail, an acceleration measurement takes place. It should not go unmentioned that are located between the acceleration sensing sensors damping elements, such as engine / transmission bearings in which the internal combustion engine is housed in the vehicle and the body of the vehicle itself.

On an automated transmission such as a dual-clutch transmission, a shift operation, following the solution proposed by the invention, proceeds as follows: A triggering signal on the automated transmission is sent to the clutch control, which is part of the transmission control. There is a detection of the vehicle acceleration and a control of the at least one clutch on the automated transmission, so that the fastest possible switching operation can be performed. A tilting movement occurring during the switching process is detected with regard to the occurring acceleration or the occurring change of the rotation angle, and there is a calculation of the effects caused by the tilting effects on the driver of the vehicle. A correction of the generated by the clutch control signals for the Umkuppelvorgang is such that the most constant acceleration acts on the driver or a targeted pulse is emitted such that a desired by the driver subjective switching strategy or switching dynamics is generated. A counter-check for the acceleration sensation acting on the driver can be achieved by means of an acceleration measurement which can be carried out on the seat rail of the driver's seat or, alternatively, can be achieved via a force measurement on the vehicle seat.

The solution proposed according to the invention can be used on automatically shifting transmissions, such as automatic torque converters, automated manual transmissions or dual clutch transmissions and the like, and includes a software function, optionally the use of at least one additional rotational speed sensor and / or acceleration sensor to be installed in the vehicle. Furthermore, by the solution proposed according to the invention a multiple use already in the vehicle in the context of ESP, ABS or ASR systems built sensors can be achieved, so that the Verschaltungsaufwand or the requirement of further to be installed in the vehicle, the acceleration detecting or rate of rotation detecting sensors can be significantly reduced.

Brief description of the drawings

With reference to the drawings, the invention will be described in more detail below. It shows:

FIG. 1 shows a comparison of a desired course of the vehicle acceleration, which is compared with an uncorrected acceleration course and a corrected course of acceleration,

FIG. 2 shows a system diagram of a transmission control proposed according to the invention, and FIG. 3 shows an acceleration sensor associated with a motor / gearbox unit. embodiments

The illustration according to FIG. 1 shows the desired course of a vehicle acceleration, which is compared with an uncorrected acceleration course and a corrected course of acceleration in the sense of the present invention.

FIG. 1 shows that a desired course 10 of a vehicle acceleration is plotted over the time axis, and the set course 10 of the vehicle acceleration, viewed from an initial level 11 over the time, remains constant over time.

Reference numeral 20 characterizes an acceleration course to be observed in a poorly performed circuit operation. In such a switching operation of an automated transmission 42, there is a shift shock, which is perceived by the driver of the vehicle by an acceleration change. In the illustration according to FIG. 1, this change in acceleration is represented as break-in 21, since a shift to be maintained continuously in the automated transmission 42 can not be realized, but a collapse of the acceleration according to the maximum 21 shown in FIG.

When implementing the solution proposed by the invention in a transmission control 58 of a motor vehicle with an automatic transmission 42, which is connected downstream of an internal combustion engine 40, the aim is to maintain the acceleration curve 30 shown in FIG. 1 with correction, with the acceleration curve 30 shown in FIG Acceleration collapse at position 31 is minimized. In the ideal case, no acceleration collapse should occur, which in practice, however, can only be achieved with great difficulty. With the solution proposed according to the invention, the corrected acceleration profile 30 is achieved, the break-in of which with respect to the minimum 31 is optimized.

As can be seen from a comparison of the uncorrected acceleration curve 20 and the corrected acceleration curve 30, the maximum break 21 occurs during the uncorrected acceleration curve 20 over a first time span 22. In contrast, In the corrected, post-adapted acceleration curve 30 according to the dashed curve in the comparison in Figure 1, a much shorter second period 32, within which the actual acceleration curve, ie the optimized actual course of the desired desired course 10 (compare straight line with initial level 11 in Figure 1) deviates.

So that the driver during the switching process, be it a downshift, be it an upshift, in an automatic transmission 42 associated with the internal combustion engine 40 undergoes no change in acceleration, the illustrated in Figure 1 optimized minimum 31 of the corrected acceleration curve 30 as possible to the desired course of acceleration (compare reference numeral 10 and output level 11 in the illustration of Figure 1) approximate. By the proposed solution according to the invention, the comfort, d. H. the perceptibility by the driver to improve decisively in a to be performed by the automated transmission 42 switching operation. In addition, the comfort quality can be seen seen over the life of the vehicle. Furthermore, can be adjusted by the proposed solution according to the invention in terms of their implementation to a transmission control 38 and a targeted strategy that takes into account targeted wishes of the driver through a targeted subjective dynamics.

Following the solution proposed according to the invention, acceleration sensors already present in the vehicle are used for carrying out the switching operations by the automated transmission 42 (cf. illustration according to FIG. 2), the comfort improvement being achieved by a deviation of the desired course 10 of the acceleration occurring on the vehicle Driver of the vehicle acts, is reduced by the actual course (see reference numeral 30 in the illustration of Figure 1) to a minimum. So that the driver, for example, does not feel a jolt during an upshift of the automated transmission 42, the acceleration should be kept as constant as possible. In contrast to the known adaptation of switching processes due to speed curves, the measurement of acceleration profiles by acceleration sensors or yaw rate sensors, as will be described further below, is more meaningful. FIG. 2 shows a schematic diagram of the system diagram of the transmission control proposed according to the invention.

It can be seen from the illustration according to FIG. 2 that the automatic transmission 42, which comprises at least one controllable clutch 44, is assigned the internal combustion engine 40 of the motor vehicle. The drive of the at least one driven axle, not shown, via a transmission output shaft 46, which is shown broken off in the illustration of Figure 2. The automated transmission 42, which contains at least one controllable clutch 44, is controlled via the transmission control 58, which contains a clutch actuation mimic. The internal combustion engine 40 includes an engine block 48 which is mounted with the body of the vehicle via bearings 50 on both sides of the engine block 48.

The illustration according to FIG. 2 shows that the transmission control 58 is supplied with different input variables. Reference numeral 54 denotes an acceleration which is transmitted via an acceleration sensor as an angle change, whether detected on the automated transmission 42 or on the engine-transmission unit 40, 42. Furthermore, the speed of the transmission output shaft 46 is transmitted as an input signal to the transmission control 58 shown here only schematically. In response, the transmission controller 58 transmits a clutch signal 52 for actuating the at least one clutch 44 to the automated transmission 42, which is connected downstream of the internal combustion engine 40.

Furthermore, the transmission control 58 is supplied as input variables with a vehicle acceleration 60 and an acceleration 68 recorded on at least one seat rail 62 of the driver's seat 66. For example, while the vehicle acceleration 60 may be detected by an acceleration sensor of an automatic driving stability program (ESP, ASR, or ABS system), an acceleration value acting on the driver is detected on at least one seat rail 62. The at least one seat rail 62 is connected to the body of the vehicle, not shown in Figure 2 and on the other hand connected via one or more force measuring devices 64 to the driver's seat 66. In the case of the at least one force-measuring device 64, with which the at least one seat rail 62 and the driver's seat 66 are connected to one another, it is for example se to a force measuring bolt, via which the force acting on the driver's seat 66 acceleration can be transmitted as an input signal 68 to the transmission control 58.

The illustration according to FIG. 3 shows an acceleration sensor which is assigned to a motor / gearbox unit.

The illustration according to FIG. 3 shows that the internal combustion engine 40 is mounted on its bearings 50 in a first engine / transmission bearing 70 and optionally in a second engine / transmission bearing 72. The engine / transmission bearings 70 and 72 rest on not shown in Figure 3 receiving surfaces in the engine compartment of the motor vehicle. The illustration in accordance with FIG. 3 shows, in a schematic manner, that the internal combustion engine 40 comprises at least one cylinder 58, in which a piston 80 delimiting the combustion chamber moves up and down. The piston 80 is connected via a connecting rod 82 with the crankshaft 84 only indicated here. The radius R also extends between the crankshaft 84, which represents a pole of rotation, and the outer circumference of a flywheel. Furthermore, the illustration according to FIG. 3 shows that a rotation rate sensor 74 is assigned to the engine block 48 in the region of the crankshaft 84. Instead of the rotation rate sensor 74, the engine block 48 may also be assigned an acceleration sensor.

The sensors 74 shown in FIGS. 2 and 3, be it a rotation rate sensor, be it an acceleration sensor, or force measuring devices 64 are all connected to the transmission control 58 shown schematically in FIG. 2 and deliver input quantities to them. Advantageously, the aforementioned acceleration or rotation rate sensors are already installed in the motor vehicle, so that the use of additional acceleration sensors to be installed in the vehicle is obsolete. Alternatively, it goes without saying that additional sensors which absorb acceleration values can be used in the motor vehicle.

For example, an acceleration of the vehicle can be calculated via the knock sensor 76 shown in FIG. 3, likewise from the sensor 74, be it a rotation rate sensor or an acceleration sensor which is assigned to the flywheel of the crankshaft 84 of the internal combustion engine 40 as shown in FIG is. If the sensor 74 is used as a procure, the angular acceleration can be measured with this and be transmitted as angular acceleration signal 54 of Figure 2 to the transmission control 58 for the automated transmission 42. On the other hand, if the sensor 74 is a rotation rate sensor associated with the automated transmission 42, the angle about the axis of rotation of the automated transmission 42 or the motor-gear unit 40, 42 can be measured via this. If a poorly performed switching operation, ie a non-jerk-free circuit on the automated transmission 42, then there is a shift shock. This has a perceptible by the driver acceleration change (see breaks 21 and 31 in Figure 1) result. As a result of the shift operation carried out in the case of the unclean load change, a reaction torque is generated in the automated transmission 42 which causes a tilting movement of either the automated transmission 42 as such or the drive unit, internal combustion engine 40 and automated transmission 42. This tilting movement can be intercepted by the at least one engine / transmission bearing 50, 72 on the bearing 50 of the internal combustion engine 40 in the motor vehicle. In addition, the tilting movement can be detected either by carrying out an acceleration measurement at a radius R about a rotation pole of the movement, or by detecting the acceleration by means of a sensor 74, which in this case is to be designed as a rotation rate sensor.

Decisive for the comfort of a switching process, however, is the acceleration, which is perceived by the driver of the motor vehicle. This acceleration can be performed, for example, by an acceleration measurement on at least one seat rail 62 of the driver's seat 66 as shown in FIG. The acceleration signal obtained is also, as shown in FIG. 2, superimposed on the transmission control 58. The measurement of the effects of the acceleration on the driver can be obtained in several ways. On the one hand, it is possible to carry out an acceleration measurement with a separate acceleration sensor. For this purpose, for example, acceleration sensors built into the vehicle, which are already present in the context of ESP, ASR or ABS sensors, can be connected to the transmission control 58 so that it receives a representative acceleration value corresponding to the acceleration of the vehicle. In addition to the acceleration sensors already installed in the vehicle, additional sensors can also be used in the vehicle. Furthermore, it is possible to use the acceleration sensor, for example, the ESP system for detecting the acceleration of the motor vehicle acting on the driver.

Finally, it is possible to detect the force acting through the acceleration force measuring bolt of a force detecting device 64 which connect the driver's seat 66 with at least one seat rail 62, which in turn is connected to the body of the motor vehicle. Between the sensors on the drive unit are damping elements, such as engine / transmission bearings 70 and 72. If a switching operation is performed, issued via the clutch control of the transmission control 58, a clutch signal 52 to the automated transmission 42 for controlling the contained therein at least one clutch 44. The vehicle acceleration 60 is detected continuously, which can be achieved by the acceleration sensors mentioned, for example, the ESP, the ASR or the ABS system or via a separate installed in the vehicle acceleration sensor 74. The at least one clutch 44th is controlled such that the fastest possible switching operation is achieved. The tilting movement occurring in the switching operation on the automated transmission 42 in response to the load change is detected by the sensor 74, according to the invention, by means of the sensor 74, be it an acceleration sensor or a yaw rate sensor. Based on the detected signals relating to the tilting movement, the effects on the driver are calculated, i. H. the effect on the vehicle acceleration 60 acting on the driver.

The correction of the clutch signal 52 actuating the at least one clutch 44 of the automated transmission 42 is effected by the transmission control 58 in such a manner that the driver learns the desired course of acceleration 60 or via the transmission control 58 by means of a modified individualized clutch signal 52 according to a preselectable shift program Pulse is transmitted to the automated transmission 42 with at least one clutch 44 to produce a subjective dynamic. The subjective dynamics can take account of sporty or comfortable driver types and be set automatically on the automated transmission 42. A check of the vehicle acceleration 60 perceived by the driver can take place via an acceleration measurement on at least one of the Seat rails 62, to which the driver's seat 66 is attached, are verified. Alternatively, a force measurement, for example via the force measuring pins 64 (i-Bolts) on the driver's seat 66 can be performed.

The inventively proposed method for carrying out switching operations on automated transmissions 42 can be performed, for example, on automated transmissions 42, which are designed as automatic shifting transmissions, as automatic torque converters, as automated manual transmissions ASG or as dual-clutch transmissions DCT. The implementation of the optimized shifting processes while minimizing the deviation from the acceleration of the acceleration during the shifting operations on the automated transmission 42 includes a software function and, if appropriate, the use of at least one rotational rate or acceleration sensor to be additionally installed in the vehicle. The solution proposed according to the invention makes it possible in a particularly advantageous manner to use multiple acceleration sensors already installed in the vehicle or acceleration sensors which are present in the context of ESP, ASR or ABS systems, or sensors or yaw rate sensors which detect torque curves and which are already connected with navigation systems or other vehicle systems on vehicles.

Claims

claims

1. A method for carrying out switching operations on an automated transmission (42) with at least one clutch (44) for motor vehicles, wherein the switching operations are triggered by a transmission control (58), comprising the following method steps: a) an acceleration value corresponding to the acceleration of the vehicle ( 54

68) is detected, b) the deviation of a desired course (10) of the acceleration of the vehicle from the actual course (20, 30) of the acceleration of the vehicle is reduced to a minimum (31) during the switching operation, and c) subsequent switching operations are performed with regard to method step b) adapted and d) during running switching / Umkuppelvorgänge the at least one clutch (44) is readjusted.

2. The method according to claim 1, characterized in that as the acceleration of the vehicle corresponding acceleration value (54, 68) an angular acceleration by means of an acceleration sensor or an angle change about an axis of rotation of the automated transmission (42) or a motor-gear unit ( 40, 42) or at the automated transmission (42) applied output torque is measured.

3. The method according to claim 2, characterized in that in an associated with the switching process load change on the automated transmission (42) occurring tilting movement of the automated transmission (42) or the motor-gear unit (40, 42) either by a Acceleration measurement at a radius R about a pivot pole (84) of the movement or by detection with a rotation rate sensor (74) is determined.

4. The method according to claim 1, characterized in that acting on the driver of the vehicle acceleration at the driver's seat (66), in particular at least one of the

Driver's seat (66) fixing seat rail (62) is detected.

5. The method according to claim 1, characterized in that the force acting on the driver of the vehicle acceleration by at least one acceleration sensor (74) of an ESP / ASR / ABS system or by a force measuring device (64) to the transmission control (58) transmitted becomes.

6. The method according to claim 3, characterized in that the tilting movement of the automated transmission (42) or the engine-transmission unit (40, 42) via a bearing (50; 70, 72) of the internal combustion engine (40) is intercepted.

7. The method according to claim 1, characterized in that the transmission control (58) a clutch signal (52) depending on the input variables: vehicle acceleration (60),

Acceleration (68) on at least one seat rail (62), rotational speed (56) of a transmission output shaft (46), angular acceleration (54),

Output torque generated at transmission output shaft (46).

8. The method according to claim 3, characterized in that from the tilting movement of the automated transmission (42) or the motor-gear unit (40, 42) with respect to acceleration and rotation angle effects on the driver are calculated and a clutch signal (52) for driving the at least one clutch (44) of the automated transmission (42) is corrected such that the driver is exposed to a constant acceleration or a targeted impulse is generated for generating a subjective driving dynamics.

9. A device for carrying out the method according to claim 1 with a the automatic transmission (42) associated with the transmission control (58) via which at least one clutch (44) of the automated transmission (42) is actuated, characterized in that the transmission control (58) the acceleration value (54, 68) corresponding to the acceleration of the vehicle via at least one acceleration sensor (76) or yaw rate sensor (74) associated with the engine / transmission unit (40, 42) or via at least one force measuring device associated with the driver's seat (66) (64).

10. The device according to claim 9, characterized in that the sensor is a motor block (48) of the internal combustion engine (40) associated sensor or an acceleration sensor (74) of an ESP / ASR / ABS system with the transmission control (58 ) connected is.

11. The device according to claim 9, characterized in that the rotation rate sensor (74) of the crankshaft (84) of the internal combustion engine (40) or at least one bearing (50; 70, 72) of the internal combustion engine (40) is associated.