A CONTROLLER AND METHOD TO ASSIST GEARSHIFT

WITHOUT DISENGAGEMENT OF CLUTCH IN A VEHICLE

Complete Specification:

The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed: Field of the invention:

[0001] The present disclosure relates to a controller and method to assist gearshift without disengagement of clutch in a vehicle.

Background of the invention:

[0002] An Engine management system (EMS) intended to assist the gear shift upon recognition of the shift intent from rider without pressing of clutch lever. The gear shift is recognized by gear position sensor, or a separate shift assist sensor. Based on the shift direction and current engine torque, either an increase or decrease in torque is to be realized and accordingly controlled by the EMS. The torque change is realized through change in ignition, air or fuel or any combination of them. In a system with Mechanical Throttle Body (MTB) as compared to an Electronic Throttle Control (ETC) system/ drive by wire, the EMS has very less control over air which in turn would have very less effect on torque change which is to be effected. Further, the control using change in ignition, air or fuel is done instantly which affects the drivability of the vehicle. There is a need to improve the drivability of the vehicle while changing engine output.

[0003] A patent literature US2021101581 discloses a quickshifter-equipped vehicle control unit and quickshifter-equipped motorcycle. A quickshifter-equipped vehicle control unit includes an engine speed calculator configured to calculate an engine speed and a shift controller configured to operate in a quick shift mode and in a normal shift mode. The quick shift mode is a mode in which upon detection of the shift operation, the shift controller adjusts an output of an engine while keeping a main clutch in an engaged state, and the normal shift mode is a mode in which upon detection of the shift operation, the shift controller controls a clutch actuator to bring the main clutch into a disengaged state. The shift controller selects the quick shift mode when the engine speed is higher than a predetermined rotational speed threshold, and selects the normal shift mode when the engine speed is lower than the rotational speed threshold. Brief description of the accompanying drawings:

[0004] An embodiment of the disclosure is described with reference to the following accompanying drawing,

[0005] Fig. 1 illustrates a block diagram of the controller to assist gearshift without disengagement of clutch in a vehicle, according to an embodiment of the present invention, and

[0006] Fig. 2 illustrates a method for assisting gearshifts without disengaging clutch in the vehicle, according to an embodiment of the present invention.

Detailed description of the embodiments:

[0007] Fig. 1 illustrates a block diagram of the controller to assist gearshift without disengagement of clutch in a vehicle, according to an embodiment of the present invention. The vehicle 100 comprises an engine 104, and an electric machine 120 coupled with a crankshaft of the engine 104. Further, an intake conduit 102 connected between an inlet of the engine 104 and a throttle body 112. The engine 104 operatively engageable with a transmission 118 through the clutch (not shown). The operatively engageable corresponds to engaging and disengaging clutch, between the engine 104 and the transmission 118, for shifting gears as per the requirement of a driver/rider. The controller 110 configured to detect shift intention, based on at least one of a gear position sensor and a shift assist sensor 106, and determine a target engine output corresponding to the detected shift intention, characterized in that, operate the electric machine 120 to assist the engine 104 in achieving the target engine output and enable/allow gearshift without clutch disengagement. The gearshift without clutch disengagement, i.e., an action by the driver, is provided/facilitated after the target engine output is obtained/reached/realized. The electric machine 120 is operated together with the engine 104 to achieve the target engine output. The driver is able to change gears without disengagement of the clutch if the target engine output after gear shift can be achieved. The target engine output is reached in very short span of time, right after the shift intention is detected. It is to be noted that, engine speed sensor and other sensor required to compute the engine output is not explained, but are used in the implementation of the present invention. The operating conditions comprises variables generally used for determining the target engine output, such as but not limited to current engine speed, engine temperature, ambient conditions, rider demand, present engine torque, engine torque after gear shift, vehicle speed etc. These are known in the art and hence not explained to keep the description simple.

[0008] The detection of shift intention through the at least one of the gear position sensor or the shift assist sensor 106, comprises detection of threshold value 1082, ..., 1084 from the respective sensor. The threshold value 1082, 1084 is different for each gear present in a gearbox of the vehicle 100, i.e., different for different gears.

[0009] According to an embodiment of the present invention, the operation of the electric machine 120 is combined with adjustment of engine operation using at least one parameter selected from a group comprising fuel injection, ignition time, and intake air. Specifically, the use of at least one parameter comprises an increase or decrease of a quantity of the fuel injection, an advancement or retardation of the ignition time, and control of a quantity of the intake air through an electronic actuator (such as electronic throttle valve or an idle control valve) positioned in the intake conduit 102 or a bypass path. The bypass path is a diversion from the intake conduit 102 for idling or other purposes. The adjustment in engine operation comprises use of the controller 110 to control the intake air by controlling the electronic actuator, control fuel injection quantity by controlling a fuel injector 114, control ignition pattern by controlling an ignition system 116, and the like. The air quantity change, fuel injection and the ignition timing are possible to be manipulated over a sequence of engine working cycle rather than performing in once engine working cycle.

[0010] The controller 110 comprises input/output interfaces having pins or ports, memory element 108 such as Random Access Memory (RAM) and/or Read Only Memory (ROM), Analog-to-Digital Converter (ADC) and vice-versa Digital-to- Analog Convertor (DAC), clocks, timers and at least one processor (capable of implementing machine learning) connected with each other and to other components through communication bus channels. The memory element 108 is prestored with logics or instructions or programs or applications and/or threshold values 1082, 1084 or predetermined sequence, which is/are accessed by the at least one processor as per the defined routines. The internal components of the controller 110 are not explained for being state of the art, and the same must not be understood in a limiting manner. The controller 110 may also comprise communication units to communicate with a server or cloud through wireless or wired means such as Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, and the like.

[0011] According to an embodiment of the present invention, the controller 110 is any one of the Engine Management System (EMS) controller 110, a Transmission Control Unit (TCU), or other internal control unit capable of executing the instructions, or an external control unit which is interfaced with the controller 110 such as over Controller Area Network (CAN).

[0012] In accordance to an embodiment of the present invention, the controller 110 is implementable in vehicle 100 comprising a two-wheeler such as a motorcycle, a moped, etc. In general, the controller 110 is usable in those vehicles 100 which involves manual change in gears such as quad bikes, snow mobiles, water sports or power sports vehicles 100 and other vehicles 100.

[0013] In accordance to an embodiment of the present invention, the assistance comprises distribution(or split) of the target engine output between the electric machine 120 and the engine 104 based on respective capacity after the detection of shift intention. Specifically, the target engine output is in terms of torque which is split into two parts, one each for the electric machine 120 and the engine 104. Alternatively, the engine 104 provides the maximum torque and any surplus torque demand, not able to be supplied from the engine 104, is supplemented by the electric machine 120. The electric machine 120 is used as a motor when assisting the engine 104. The electric machine 120 assists as the motor when an increase in engine output (or increase in torque or during downshift) is required. In an embodiment, the electric machine 120 is an Integrated Starter Generator (ISG) or a starter generator.

[0014] In accordance to an embodiment of the present invention, the throttle body 112 is any one of a Manual Throttle Body (MTB) system and an Electronic Throttle Control (ETC) system. The control of fuel injection, ignition time and intake air through bypass path are applicable for the MTB system, and control of the fuel injection, ignition time and intake air through intake conduit 102 and bypass path are applicable for the ETC system. In short, the control of air quantity, fuel injection and ignition time are applicable for both MTB system and ETC system.

[0015] According to an embodiment of the present invention, the engine output corresponds to engine torque which is either increased or decreased based on the upshift or downshift request and other operation conditions as detected by the controller 110. Now, to aid seamless clutch-less (without manipulation or disengagement of the clutch) gearshift in the vehicle 100, the torque change request is realizable in the following ways. A reduction in engine torque is also possible through fuel cut-off or enleanment which is either completed in an instant or spread over a sequence of the engine working cycles. In an alternative, the ignition timing is retarded or cut-off completely or in a sequential manner. As yet another alternative, the by-pass air path is closed completely or in a sequential manner. Based on configuration and operating point, any combination of intake air control, fuel injection and ignition timing is adopted for achieving the engine torque change. The torque reduction is applicable for both MTB system and ETC system. The sequential manner corresponds to adjustment of engine output/torque in at least two engine working cycle in predetermined or configurable pattern, where each engine working cycle comprises intake stroke through exhaust stroke. [0016] Similar to the torque reduction as described above, an increase on torque is explained below. In the vehicle 100 with the electric machine 120, the electric machine 120 has the ability to produce certain torque independent of operation state of the engine 104. This ability is used to provide additional short duration torque to aid during clutch-less gearshift. When the shift intention is detected, and the controller 110 determines a requirement of increased in torque, the delta torque is communicated the electric machine 120 (through respective Motor Control Unit (MCU)) for realization and relevant feedback. In the vehicle 100 with by-pass air feature, the bypass path is openable during clutch-less gearshift to meet the additional torque request, either completely or in sequential manner. Alternatively, provide additional fuel / enrichment during gearshift in a complete or sequential manner. In yet another alternative, ignition timing is advanced which is again in complete or a sequential manner. Further, based on the controller 110, any combination of bypass-air, fuel enrichment or ignition advancement is adopted for achieving the torque change.

[0017] According to the present invention, a working of the controller 110 is explained to elaborate the operation/control of the electric machine 120. Consider the ISG as the electric machine 120, is available in the vehicle 100 and the vehicle 100 is driven at 3 ^rd gear. The driver intends to downshift, and therefore start moving the gear lever in corresponding direction, which is detected before the complete movement of the gear lever. The controller 110 computes the torque needed and distributes the target engine output/torque between the engine 104 and the ISG. The MCU receives the input from the controller 110 and controls the ISG, and assists the engine 104 in realizing the target engine torque. Alternatively, the controller 110 directly controls the ISG. The completion of the torque change to the target engine output enables the driver to change the gear lever to 2 ^nd gear position without disengaging the clutch, and provides smooth gearshift experience. Thus, existing electric machine 120 is used to provide smooth gearshift functionality. The smooth gearshift functionality without clutch disengagement/ manipulation is also referred to as quick shift. [0018] According to an embodiment of the present invention, the vehicle 100 comprises the engine 104, and the ISG coupled with the crankshaft of the engine 104. The vehicle 100 also comprises the intake conduit 102 connected between the inlet of the engine 104 and the throttle body 112. The engine 104 operatively engageable with the transmission 118 through the clutch (not shown). The operatively engageable corresponds to engaging and disengaging clutch, between the engine 104 and the transmission 118, for shifting gears as per the requirement of a driver/rider. The controller 110 configured to detect shift intention, based on at least one of the gear position sensor and the shift assist sensor 106, and determine the target engine output corresponding to the detected shift intention, characterized in that, operate the ISG to assist the engine 104 in achieving the target engine output. The gearshift without clutch disengagement, i.e., the gear lever shifting action by the driver, is provided/facilitated/enabled after the target engine output is obtained/reached/realized. The ISG is operated together with the engine 104 to achieve the target engine output. The driver is able to change gears without disengagement of the clutch if the target engine output after gear shift can be achieved.

[0019] Fig. 2 illustrates a method for assisting gearshifts without disengaging clutch in the vehicle, according to an embodiment of the present invention. The vehicle 100 comprises the engine 104, and the electric machine 120 coupled with the crankshaft of the engine 104. The vehicle 100 also comprises the intake conduit 102 connected between the inlet of the engine 104 and the throttle body 112. The engine is operatively engageable with the transmission 118 by the clutch. The method comprises plurality of steps of which a step 202 comprises detecting shift intention, based on at least one of the gear position sensor and the shift assist sensor, and determining the target engine output corresponding to the detected shift intention and other operating conditions. The operating conditions are explained above. A step 204 comprises operating the electric machine 120 to assist the engine 104 in achieving/realizing the target engine output and enabling/allowing gearshift without clutch disengagement. The gearshift without clutch disengagement, i.e. an action by the driver, is facilitated/provided after obtaining/realizing the target engine output.

[0020] According to the method, operating the electric machine 120 is combined with adjustment of engine operation using at least one parameter comprising fuel injection, ignition time, and intake air. The adjustment in engine operation comprises changing, i.e., increasing or decreasing, of output of the engine 104 using at least one parameter comprising fuel injection, ignition time, and intake air. Further, the use of the at least one parameter comprises, increasing or decreasing quantity of the fuel injection, advancing, or retarding the ignition time, and controlling the quantity of the intake air through the electronic actuator positioned in the intake conduit 102 or the bypass path.

[0021] According to the present invention, the assistance comprises distributing (or splitting) the target engine output between the electric machine 120 and the engine 104 based on respective capacity at the instant of the detection of shift intention. Further, the electric machine 120 is operated for assisting the engine 104 when an increase in target engine output is requested. The electric machine 120 is an Integrated Starter Generator (ISG). Further, the throttle body 112 is any one of the Manual Throttle Body (MTB) system and the Electronic Throttle Control (ETC) system. The intake air quantity through bypass path, fuel injection and ignition time are applicable parameters for both MTB system and ETC system.

[0022] According to the present invention, the controller 110 and methodology for enabling clutch less gearshift in the Engine Management System (EMS) in the vehicle 100. The present invention is retrofittable to existing vehicles 100, thereby providing low cost solutions and economical solutions. The use of ISG for providing quick/instant quick shift functionality increases the drivability and the driving experience. [0023] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.