TRANSMISSION CONTROLLER

FIELD OF THE INVENTION

The present invention relates to continuous position sensing of gear and clutch position for an automatic manual transmission (AMT) engine equipped vehicle.

BACKGROUND

Generally in an automated manual transmission (AMT) vehicle gear and clutch actuation is controlled by an electric control unit (ECU). The gear and clutch actuation is performed by two independent electric actuators. The electric actuators work based on the position of the gear and clutch. The position of gear and clutch is controlled in a closed loop manner. Typically, the current position of the clutch and gear is sensed by two independent position sensors. The said sensors are mechanically connected to the gear lever and clutch actuation system respectively. The desired position of the clutch and gear is independently calculated by the ECU based on information available from different input sensors. The ECU controls the input power to both the shift actuators based on error between desired position and actual position. The accurate position sensing for gear and clutch is very significant for the calculating the power input to the actuators. If this sensing is not correct, the gear may over shift or it may never shift to the next desired gear position. In case of incorrect sensing of clutch position, clutch may not be disengaged or engaged properly. The above mentioned facts can lead to bad drivability for an AMT based vehicle.

In existing AMT system, the position sensing is realized by two position sensors which are mounted on the clutch actuation system and gear shift cam shaft respectively. Under certain conditions, there is a likely chance of sensor malfunctioning. In such condition when the sensor malfunctions, the whole automatic manual transmission system based on sensor input collapses. There is need to develop an automatic manual transmission system which can function without sensor technology and gives the desired results.

SUMMARY

An object of the present invention is to provide a method for continuous sensing of gear and clutch position without a sensor (s) in an automatic manual transmission equipped engine.

Another object of the present invention is to provide a system which simultaneously senses the position of gear and clutch and diagnoses the clutch health.

Yet another object of the present invention is to provide a cost effective method for continuous sensing of gear and clutch position.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein

Figure 1 shows a conventional scooter type vehicle.

Figure 2 shows an automatic manual transmission equipped engine according to the present invention.

Figure 3 shows a gear shift mechanism and clutch shift mechanism according to the present invention.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter with different embodiments. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather those embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the invention to those skilled in the art.

The present invention is illustrated with a scooter type vehicle. The illustrated scooter type vehicle comprises a so called low floor board type vehicle and the term scooter as used herein should not be inferred to restrict the maximum speed, the displacement amount or the like of the vehicle. Moreover the present invention is not limited to a scoter type vehicle and certain features, aspects and advantages of embodiments of the present invention can be used with other types of two wheelers such as motorcycle, step thru and the like.

With reference to Figure 1,1 denotes a front wheel, 2 denotes a front fork, 3 denotes a front fender, 4 denotes a front cover, 5 denotes a leg shield made of resin or metal, 6 denotes a handle bar cover, 7 denotes a headlight, 8 denotes a handle bar ,17 denotes a rear fender and 18 denotes tail lamp.

The centre of the body forms a low floor board 9 for functioning as a part for putting feet and a under cowl 10 which is located below the rider's seat and covers at least a part of the engine, The under cowl is made up of metal or resin. The under cowl is hinged to the seat 11. A utility box 12 opens from the rear end to hinged portion. The utility box 12 is provided under the seat extending longitudinally of a vehicle body and the inside of the utility box has a large capacity so that a large article can be housed. A main frame 14 extended along the center of the body before and behind and made of a metallic pipe and is provided under the floor board 9. A swing type power unit 13 is coupled to the rear end of the main frame 14.

A rear wheel 15 is supported on one side of the rear end of the swing type power unit 13. The swing type power unit 13 is suspended in the rear of a body frame.

The side covers 16 both on left and right sides, covers the utility box 12 and other parts of the vehicle, thereby providing a good appearance to the vehicle.

According to one embodiment of the present invention and referring to Figure 2 and Figure 3, a system is provided for continuous position sensing of gear shift lever and clutch shift lever comprises an automatic manual transmission equipped engine 301 having a clutch actuator 201 configured to actuate clutch 201 and shift actuator 202 configured to shift the change gears. A controller 203 for activating the shift actuator 202 and clutch actuator 201. One motor input current sensing means for shift actuator 204 and another motor input current sensing means 205 for clutch actuator 201. The controller calculates input power to shift actuator 206 and clutch actuator 207 respectively based on motor input current for shift actuator and clutch actuator respectively.

The controller or ECU 203 reads input current OR input current and voltage (i.e power) from respective sensing system. The samplings of the parameters are performed at considerably high frequency so that the dynamics of actuation system is predicted perfectly. The sensing system can be placed inside the ECU 203 or it can be placed in a separate unit. If the sensing unit is designed as a separate unit, this unit shares the information with the ECU 203 unit via a data communication or by means of an analogue output. The ECU 203 segregates the data in small clusters for further processing. The length of the data clusters and number of total data cluster is determined with respect to the actuation mechanism. The clustering of these data reduces the calculation load on the ECU 203. The value of the input current or input power reflects the load on the actuation shaft.

Clutch actuation system can be expressed as below:
d2 X K I =K X +M Spri"g Clutch _ actuator Clutch _ actuator Actuation _ Spring Spring Actuation _ Spring j 2 where is ciutch_actuator js tne torque constant of the clutch shift actuator. dutch_actuator js the instantaneous input current of the clutch shift actuator. Tf Actuationtipnng js a constant which is a function of clutch spring and actuation mechanism.

spring js the ciutch position.

Actuation_sPring js a constant which is function of mass of the actuation system.
The aforementioned model shows a dynamic relation between input current or input power of the clutch actuator to the clutch position.

Gear actuation system can be expressed as below:
„ T * _ f ""Gearshift_Cam „ " "Gearfnift Cam Gearshift actuator Gearshift _ actuator ~ Actuation _ system , Actuation _ system , 2 n " "Gearshift Cam rActuation svstem 7j at Where is Gearshift_actuator js the torque constant of the gear shift actuator Gearshift_actuator jg tne instantaneous input current of the gear shift actuator

Actuation_System jg the jnertja 0f the actuation system Gearshift_cam js fne angu|ar position of the gear shift cam Actuation_syStem js tne gtjffness of the gear shift cam Aff Gearshift_cam jg tne angliar difference of the gear shift cam PActuation_system jg the damping of the gear shift cam

The above mentioned model shows a dynamic relation between input current or input power of the gearshift actuator to the gearshift cam position.

The above two models are realised through experimental results in the ECU 203. The results of input current or input voltage and current are stored with respect to the position in a look up table. The instantaneous values of the input current or power are compared with the lookup table to determine the position value.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the claims.

WE CLAIM

1. A system for continuous position sensing of gear shift lever and clutch shift lever comprising:

an automatic manual transmission equipped engine having a clutch actuator configured to actuate clutch and shift actuator configured to shift the change gears;

a controller for activating the shift actuator and clutch actuator; and atleast one motor input current sensing means for shift actuator and clutch actuator;

wherein said controller based on motor input current for shift actuator and clutch actuator provides input power to shift actuator and clutch actuator respectively.

2. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 1, wherein the said automatic manual transmission equipped engine is preferably for a scooter type vehicle.

3. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 1, wherein the said automatic manual transmission equipped engine is preferably for a step thru vehicle.

4. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 1, wherein the said automatic manual transmission equipped engine is preferably for a motorcycle vehicle.

5. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 1, wherein the said controller can be fed with motor input power to shift actuator and motor input power to clutch actuator.

6. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 1, wherein the said motor input current sensing means is preferably placed inside the controller.

7. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 1, wherein the said motor input current sensing means is preferably placed in a separate unit outside the controller.

8. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 7, wherein separate unit shares the information with the controller preferably by data communication means.

9. The system for continuous position sensing of gear shift lever and clutch shift lever as claimed in claim 7, wherein separate unit shares the information with the controller preferably by analogue output.

10. A method of continuous position sensing of gear shift lever and clutch shift lever for automatic manual transmission comprising: sensing motor input current for shift actuator;

sensing motor input current for clutch actuator;

sampling of the shift actuator motor input current and clutch

actuator motor input current at high frequency;

segregating and clustering of data received after sampling; and

modulating the motor input current(s) for shift actuator and clutch
actuator.

11. A system and method for continuous position sensing of gear shift lever and clutch shift lever as substantially shown and described.