DE102018104008A1 - Method for detecting a gear in a manual transmission in vehicles with a friction clutch - Google Patents

Abstract

The invention relates to a method for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch (4) is automatically operated by means of an electric motor (8). In order to prevent damage to gear teeth in the transmission, a shift force (F_x) is estimated from a differential travel of a shift lever travel (x-SH) and a transmission travel (xG), with the estimated shift force (Fx) elasticities (c_IS) an internal circuit of the manual transmission (3) are corrected and with the corrected elasticities (c_IS) of the internal circuit (17) a shift position (x) of a transmission travel sensor (23) used for gear recognition is adjusted.

Description

The invention relates to a method for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch is automatically operated by means of a mechatronic actuator.

In transmissions with an electronic clutch management (EKM), a motor intervention is carried out for the automated control of the clutch. This allows the driver to perform a gear shift on the shift lever, without first to make the drive train of the vehicle by removing the accelerator pedal torque-free.

From the still unpublished German patent application of the applicant with the file number DE 10 2016 209 196.4 For example, there is known a method of detecting a gear in a manual transmission in vehicles having a friction clutch. In this method, in a starting operation of the vehicle, a map consisting of clutch torque of the friction clutch and Fahrzeugbeschleunigungswerten the vehicle divided into at least two areas by a limit function, wherein the first area is associated with a first gear and the second area a second gear and the of the starting operation measured value pairs are assigned to the first gear, if they are within the first range and assigned to the second gear, if they are within the second range. Due to this comparison method, faulty, in particular premature, gear recognition can occur, which can lead to the misrecognition of gear teeth in the transmission. For such damage may be the cause that due to high switching forces and unavoidable elasticities in the internal circuit of the transmission a gear is incorrectly recognized as engaged, although the synchronization is not completed or the gear has not been fully inserted. As a result, the clutch is closed again before the end of the shift and the gear is then loaded under load after completion of the synchronization process.

The invention has for its object to provide a method for gear detection in a manual transmission in vehicles with a friction clutch in which the damage to the gear teeth in the transmission is prevented by a correct gear detection.

According to the invention the object is achieved in that the gear recognition is determined by evaluating an input speed and an output speed of the transmission. Thus, existing speed sensors can be used in a particularly cost-effective manner for a simple gear recognition in the transmission. Alternatively, the wheel speed can be determined via wheel speed sensors for the transmission output speed. Thus, a simple safeguard of the gear recognition.

A development of the invention relates to a method for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch is automatically operated by means of an electric motor. To prevent the damage of the gear teeth in the transmission, a shift force is estimated from a differential path of a shift lever and a transmission path, which are corrected with the estimated shift elasticities of an internal circuit of the manual transmission and adjusted with the corrected elasticities of the inner circuit used for gear detection shift position of a transmission sensor. Due to this compensation of the elasticities of the internal circuit, high forces that lead to increased shift positions on the transmission sensor, can be corrected so that before a complete meshing of the new gear, a gear detection threshold can be reliably evaluated. As a result, damage to the gear teeth of the transmission are reliably prevented.

In one embodiment, a shift lever sensor and / or a transmission sensor for determining the gear path are used to determine the shift lever. By means of such simple sensors reduces the computational effort to evaluate the gear detection A reliable gear detection is still guaranteed. As a transmission sensor advantageously two sensors can be used, namely a transmission sensor-selecting and a transmission sensor switching, which determine the movement of a shift finger in the inner circuit, consisting of shift rail, shift finger and shift fork exactly.

In one embodiment, the shift force is estimated using a rigidity of an external circuit of the manual transmission from the shift lever and the transmission path. By including the rigidity of the external circuit of the manual transmission for determining the switching force, a reliable compensation of the elasticities of the internal circuit of the transmission is made possible.

In one embodiment, a position of a gear end position of the gearbox is determined from the corrected shift position of the transmission sensor regardless of the applied shift force. Thus, manufacturing tolerances and wear of the transmission can be at least partially eliminated from the determination of the speed detection thresholds. This procedure can be used both at commissioning of the vehicle in the production or in a workshop to be executed.

In one embodiment, the determined gear end position of the gearbox is adapted during its operation, wherein at least one gear detection threshold is adapted relative to the gear end position. Thus, at any time can determine a precise Gangendlage and adjust the Gangerkennungsschwelle to this.

Advantageously, at least one gear detection threshold, which exceeds the transmission path determined by the transmission sensor for reliable gear recognition, is raised by the elasticity of the inner circuit and compared to an unchanged shift position of the transmission sensor. By such a comparison also takes place a reliable Gangerkennung.

Advantageously, after the gear detection by the transmission sensor from the transmission output speed and a predetermined gear ratio, the transmission input speed is determined, wherein a measured from the measured transmission input speed and the specific transmission input speed differential speed is proportional to a differential speed at a gearing of the shifted gear, being closed to a transmission synchronization, if the differential speed is approximately zero. By such an evaluation of the input and output speed of the transmission, the determined by the difference of the Schalthebelweges and the transmission path gear recognition can be plausibility.

In one variant, a gear is considered to be fully engaged when the differential speed of transmission input and transmission output speed is sufficiently small over a predetermined period of time. Only when the engagement of the gear on this speed condition is confirmed, the clutch can be closed. Thus, an early closing of the clutch can be prevented before engaging the gear, which is why damage to the gear teeth are prevented in the transmission.

A further development of the invention relates to an arrangement for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch is connected to the automatic control with a clutch actuator having an electric motor, which is coupled to a control unit which is arranged with a transmission path sensor arranged in the transmission is connected and a manually operable lever is coupled via an external circuit to the transmission. In order to prevent damage to the transmission by a misrecognition of the gear, a shift path sensor is positioned on the shift lever, which leads to the control unit, which in dependence on the determined by the shift travel sensor and the transmission path sensor a switching force for correcting an elasticity of an internal circuit of the transmission determines and adapts with the corrected elasticities of the internal circuit used for gear detection shift position of the transmission sensor. With this arrangement, a very simple way is provided to prevent damage to the gearing by a faulty premature gear recognition.

Advantageously, with respect to a transmission input shaft, a transmission input speed sensor and a transmission output shaft, a transmission output speed sensor positioned leading to the control unit, which determines the gear recognition by evaluating an input speed and an output speed of the transmission. Thus, a very simple way to determine a gear detection at the right time is established.

The invention allows numerous embodiments. One of them will be explained in more detail with reference to the figures shown in the drawing.

• 1 eine Prinzipdarstellung eines elektronischen Kupplungsmanagementsystems,
• 2 eine vereinfachte Darstellung der erfindungsgemäßen Anordnung zur Gangerkennung,
• 3 ein Ersatzmodell der erfindungsgemäßen Anordnung gemäß 2.

Show it:

• 1 a schematic diagram of an electronic clutch management system,
• 2 a simplified representation of the arrangement according to the invention for gear recognition,
• 3 a replacement model of the inventive arrangement according to 2 ,

In 1 is a schematic diagram of an electronic clutch management system 1 shown in which between a motor 2 and a gearbox 3 a self-adjusting coupling 4 is arranged. The gear 3 is with the clutch 4 via a transmission input shaft 5 connected while the transmission output via a transmission output shaft 6 to the vehicle wheels 7 leads. The coupling 4 is powered by one, by an electric motor 8th comprehensive actor 9 operated, the electric motor 8th a piston in a master cylinder 10 operated, by means of which a hydraulic fluid to a slave cylinder 11 is promoted, causing the piston 12 the slave cylinder 11 the coupling 4 actuated. The actor 9 is doing by a control unit 13 driven.

How out 2 shows, in which a Ausgangsführungsbeispiel the inventive arrangement 14 is shown, is the control unit 13 with a shift lever sensor 15 connected, which towards a driver-operated shift lever 16 is arranged. The shifter 16 is with an internal circuit 17 of the transmission 3 , consisting of a shift rail 18 and a switching element 19 , connected. In this case, a connection of the shift lever takes place 16 via an external circuit 20 that a train 21 for the switching movement and a train 22 for the selection movement to the transmission 3 transfers. The control unit 13 is with two gearpath sensors, which are on the gearbox 3 are positioned, wherein a transmission sensor switching 23 and a transmission sensor select 24 exists to accurately track the movement of the switching element 19 , which by a corresponding movement of the shift rail 18 and the shift fork is caused to detect.

This in 2 illustrated arrangement 14 is in 3 represented by a replacement model to those at the operation of the shift lever 16 to be able to clarify occurring shift forces or shift travel closer. The shift lever sensor 15 It has the task to recognize the driver's intention to shift by finding a way x_SH the shift lever 16 detected and sent to the control unit 13 forwards. From the through the transmission sensor switching 23 determined traveled transmission path x_G of the switching element 19 as well as the known stiffness c_AS of the external circuit 20 between these sensors, the current switching force F_x is estimated. For a linear analysis: $$\text{f\_x}=\left(\text{x\_SH}-\text{x}\_\text{G}\right)*\text{c\_AS}\text{,}$$

Generally speaking, therefore, the switching force f_x a function of the travel x_SH of the shift lever sensor 16 , the way x_G of the transmission 3 and the stiffness c_AS of the external circuit 20 ,

Allgemein gilt: $$\text{x}=\text{f}\left(\text{x\_G},\text{ F\_x},\text{ c\_IS}\right).$$

With this estimated switching force f_x can a compensation of the elasticities c_IS of the internal circuit 17 be performed. There are two possibilities for this: In a first case, the shift position of the transmission sensor switch 23 with the estimated elasticity of the internal circuit becomes the gear recognition 17 corrected and uses this position x for the gear recognition. In the considered simple linear relationship: $$\text{x}=\text{x}\_\text{G}-\left(\text{F}\_\text{x / c\_IS}\right)$$

In general: $$\text{x}=\text{f}\left(\text{x\_G}.\text{f\_x}.\text{c\_IS}\right),$$

In a second case, the gear detection thresholds become the estimated elasticity c_IS of the internal circuit 17 raised and in the gear recognition with the unchanged position of the gearbox sensor switching 23 compared. If the unchanged position of the gearbox sensor exceeds switching 23 the speed detection thresholds, it is concluded that the gear is reliably engaged.

With one in the case 1 corrected sensor position can also determine a position of the gear end position in independence of an applied switching force. The gear end position is thereby during operation of the electronic clutch management system 1 adapted, wherein the gear detection thresholds are defined relative to the adapted end position.

As an alternative solution or supplement to the previously explained gear recognition, the gear recognition is also carried out by evaluating an input and output speed of the transmission 3 , In particular, this can be done a plausibility of the described method of gait recognition. Once the gear on the transmission sensor switching 23 is recognized, from the transmission output speed and the known gear ratio, an input speed of the transmission 3 certainly. Subsequently, a difference is formed from the measured input speed and the speed determined by the gear ratio. If the difference is approximately zero over an observation period, then it can be assumed that the gear recognition is correct.

This is z. As is the case when the absolute differential speed of input and output speed of the transmission 3 is less than 50 revolutions / minute for at least 30 ms. The through the clutch actuator 4 to be controlled clutch 4 is thus closed only when it is confirmed on the basis of this speed condition that the gear is actually engaged.

LIST OF REFERENCE NUMBERS

1

electronic clutch management system

2

engine

3

transmission

4

clutch

5

Transmission input shaft

6

Transmission output shaft

7

vehicle wheels

8th

electric motor

9

actuator

10

Master cylinder

11

slave cylinder

12

piston

13

control unit

14

arrangement

15

lever sensor

16

gear lever

17

indoor circuit

18

shift rail

19

switching element

20

external circuit

21

Pull for switching movement

22

Train for dial motion

23

Transmission sensor switching

24

Transmission sensor- Select

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102016209196 [0003]

Claims (10)

Method for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch (4) automatically by means of an electric motor (8) is operated, characterized in that the gear recognition by evaluating an input speed and an output speed of a transmission (3) is determined. Method for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch (4) is automatically operated by means of an electric motor (8), characterized in that from a differential travel of a shift lever path (x-SH) and a transmission path (x_G) a Switching force (F_x) is estimated, with the estimated switching force (F_x) elasticities (c_IS) of an internal circuit of the manual transmission (3) are corrected and with the corrected elasticities (c_IS) of the internal circuit (17) used for gear recognition switching position (x) of Gearbox sensor (23) is adjusted. Method according to Claim 2 , characterized in that the switching force (F_x) is estimated by taking into account a rigidity of an external circuit (20) of the manual transmission (3) from the shift lever (x_SH) and the transmission path (x_G). Method according to Claim 3 , characterized in that from the corrected shift position (x) regardless of the applied switching force (F_x) a position of a gear end position of the gearbox (3) is determined. Method according to Claim 4 , characterized in that the determined gear end position of the gearbox (3) is adapted during its operation, wherein at least one gear detection threshold is adapted relative to the gear end position. Method according to Claim 1 or 2 , characterized in that at least one gear detection threshold, which exceeds the transmission path (x_G) determined by the transmission sensor (23) for safety, to the elasticity (c_IS) of the inner circuit (17) is raised and with an unchanged shift position (x) of the transmission sensor (23) is compared. Method according to at least one of the preceding claims, characterized in that after the gear recognition by the transmission sensor (23) from the transmission output speed and a predetermined gear ratio determines the transmission input speed, wherein a measured from the measured transmission input speed and the specific transmission input speed differential speed to a differential speed at a gearing of the gear ratio is proportional, wherein a gear synchronization is concluded when the differential speed is approximately zero. Method according to at least one of the preceding claims, characterized in that a gear is considered to be completely engaged when the differential rotational speed from the transmission input and transmission output rotational speed over a predetermined period is sufficiently small. Arrangement for gear recognition in a manual transmission in vehicles with a friction clutch, in which the friction clutch (4) for automatic control with an electric motor (8) having clutch actuator (4) is connected, which is coupled to a control unit (13), which with a in the transmission (3) arranged transmission path sensor (23) is connected and a manually operable shift lever (16) via an external circuit (20) with the transmission (3) is coupled, characterized in that on the shift lever (16) a shift travel sensor (15 ) which leads to the control unit (13) which, depending on the differential path determined by the shift travel sensor (15) and the transmission travel sensor (23), has a shift force (F_x) for correcting an elasticity (c_IS) of an internal circuit (17) of the Gear (3) determines and with the corrected elasticities (c_IS) of the internal circuit (17) used for gear detection switching position (x) of the gear ebesensors (23). Arrangement according to Claim 9 characterized in that opposite to a transmission input shaft (5) a transmission input speed sensor and a transmission output shaft (6) a transmission output speed sensor are positioned, leading to the control unit (13), which determine the gear recognition by evaluating an input speed and an output speed of the transmission (3) ,

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