A CONTROLLER AND METHOD TO ENABLE GEARSHIFT IN A

VEHICLE WITHOUT DISENGAGEMENT OF CLUTCH

2. Applicants: a. Name: Bosch Limited

Nationality: INDIA

Address: Post Box No 3000, Hosur Road, Adugodi, Bangalore

- 560030, Karnataka, India b. Name: Robert Bosch GmbH

Nationality: GERMANY

Address: Stuttgart, Feuerbach, Germany

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 enable gearshift in a vehicle without disengagement of clutch.

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 GB2504835 discloses a motorcycle gearshift assembly having a gearshift assistant for changing gear without actuation of the clutch, and method therefor. The motorcycle gearshift assembly has a gearshift assistant comprising a translation device for transforming a rotational movement performed by means of a gearshift lever, and facilitates a method of changing gear on a motorcycle gearshift assembly without actuation of the clutch, comprising the steps of moving a gearshift lever, causing springs to compress. A sensor detects movement of the lever above a predefined amount and causes the engine to be speeded up or the ignition to be interrupted, as appropriate, thereby allowing the gearshift shaft to be rotated by the relief of springs, changing gear without requiring operation of the clutch.

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 enable gearshift in a vehicle without disengagement of clutch, according to an embodiment of the present invention, and

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

Detailed description of the embodiments:

[0007] Fig. 1 illustrates a block diagram of the controller to enable gearshift in a vehicle without disengagement of clutch, according to an embodiment of the present invention. The vehicle 100 comprises an engine 104, 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 of 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 and operating conditions, and adjust engine operation to obtain the target engine output and to allow smooth gearshift without disengagement of the clutch, characterized in that, the adjustment in engine operation is effected over at least two engine working cycles in a sequential manner. The operating conditions which are used to determine the target engine output comprises engine speed, engine temperature, ambient conditions, rider demand, present engine torque, engine torque after gear shift, vehicle speed, inclination of a road and other known variables of the engine, which are used based the requirement and/or their availability in the vehicle 100. 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. These operating conditions are known in the art and hence not explained to keep the description simple. The smooth gearshift functionality without clutch disengagement/manipulation is also referred to as quick shift.

[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. The adjustment in engine operation comprises change , i.e. increase or decrease of output of the engine 104 using at least one parameter 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 air 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.

[0009] 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.

[0010] 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).

[0011] 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.

[0012] In accordance to an embodiment of the present invention, the adjustment in engine operation is effected by distribution of the adjustment over the at least two engine working/operation cycles in the sequential manner from an instant of determination of target engine output. The sequential manner is selected from at least one of consecutive sequence, alternate sequence, staggered sequence, and a configurable sequence, where each of the at least two engine working cycle comprises intake stroke through exhaust stroke. The configurable sequence denotes that a custom sequence is possible based on specific requirements. The engine operation is adjusted within a shifting phase corresponding to the determined target engine output. The shifting phase is the predetermined time interval starting from the detection of shift intention till the time the shift must get completed. The shifting phase is either same or different for different gears.

[0013] 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 control through bypass path are applicable for the MTB system, and control of the fuel injection, ignition time and intake air through both intake conduit 102 and the bypass path are applicable for the ETC system.

[0014] 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 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 torque is 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. In 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 torque change. The torque reduction is applicable for both MTB system and ETC system.

[0015] Similar to the torque reduction as described above, an increase on torque is explained below. In the vehicle 100 with by-pass air feature, the bypass path is openable in a complete or sequential manner during clutch-less gearshift to meet the additional torque request. 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.

[0016] According to the present invention, a working of the controller 110 is explained to elaborate the sequential control using waveforms 120. The waveforms 120 are just for representational purposes and should not be understood in limiting manner. The X-axis is number of engine working cycles and Y-axis represents output control in terms of torque change request in percentage. In sequential control, the parameters i.e. air quantity, fuel injection and ignition timing are used. The enleanment/enrichment or cut-off of fuel or retardation/advancement or cut-off of the ignition time or increase/decrease of air quantity is executed in phased/sequential manner over a period of engine working cycles till the torque is matched as per the gear shift and driver demand. For example, if the driver changes a gear position from 3 ^rd to 2 ^nd , the controller 110 first detects the shift intention before the gear position is changed. The controller 110 determines the target engine torque based on the detected gear change and other operating conditions, which suppose translates to 50% torque reduction. The controller 110 performs the injection cut-off/reduction and/or ignition retar d/cut-off and/or air quantity is reduced once in every five engine working cycles rather than continuously, till the target engine torque is achieved. If the torque reduction is 10 % or 90 %, the injection cut-off and/or ignition retard/cut-off and/or air quantity reduction is performed once in every nine cycles or every alternate engine working cycle respectively. The similar steps are adopted for air quantity increase, fuel enrichment and ignition advance by the controller 110. The engine working cycles in which the torque reduction or increase is achieved is changeable based on engine speed, load, and drivability. A first waveform 122 shows manipulation of air quantity or fuel injection or ignition in every ten engine working cycles. A waveform 124 shows the manipulation of air quantity or fuel injection or ignition in a sequence of pattern comprising at fourth cycle, and twice in alternate two cycles. The pattern of the sequence then continues. A waveform 126 shows that the air quantity/fuel injection/ignition is increased/decreased or advanced/retarded at every alternate engine working cycle. A waveform 128 shows that air quantity/fuel injection/ignition is manipulated after every two alternate engine working cycles followed by no manipulation for continues two engine working cycles. A waveform 130 shows manipulation of air quantity/fuel injection/ignition once in five engine working cycles. Thus, the manipulation is done by changing the percentage of duty cycle of the air control/fuel injection/ignition to adjust the engine operation in sequential manner.

[0017] Fig. 2 illustrates a method for enabling gearshifts in the vehicle without disengaging clutch, according to an embodiment of the present invention. The vehicle 100 comprises the engine 104, 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. A step 204 comprises adjusting engine operation for obtaining the target engine output and for allowing smooth gearshift without disengagement of the clutch. The step 204 of the method is characterized by the adjustment in engine operation is effected over the at least two engine working cycles in the sequential manner. The transmission 118 remains engaged with the engine 104 through the clutch.

[0018] 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.

[0019] According to the present invention, adjustment in engine operation is effected by distributing the adjustment over the at least two engine working cycles in the sequential manner from the instant of determination of target engine output. The sequential manner is selected from at least one of consecutive sequence, alternate sequence, staggered sequence, and the configurable sequence, where each of the at least two engine working cycle comprises intake stroke through exhaust stroke. The configurable sequence denotes that a custom sequence is possible based on specific requirements. The engine operation is adjusted within the shifting phase corresponding to the determined target engine output. 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 through bypass path, fuel injection and ignition time are applicable parameters for the MTB system, whereas the fuel injection, ignition time and intake air through intake conduit 102 and the bypass path are applicable parameters for the ETC system.

[0020] 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. The sequential manner of control provides additional level of control to provide smooth gear shifting experience to the driver.

[0021] 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.