Claims:We claim:
1. A controller (110) to provide braking assistance in a vehicle (100) with an Automated Manual Transmission (AMT) (114), characterized in that, said controller (110) configured to:
monitor occurrence of triggering condition for braking assistance, and while occurrence of said triggering condition remains true;
calculate a target engine speed for a lower gear position from a current gear position, and
control and shift said AMT (114) to said lower gear position when said calculated target engine speed is lower than a threshold limit.

2. The controller (110) as claimed in claim 1, wherein said triggering condition comprises at least one of a vehicle deceleration above a threshold rate, and a fully pressed brake pedal.

3. The controller (110) as claimed in claim 2, wherein said vehicle deceleration is determined using at least one of a speed sensor (102, 108), an accelerometer, and an Inertial Measurement Unit (IMU) (118), and said fully pressed brake pedal is detected using a brake pedal sensor (104).

4. The controller (110) as claimed in claim 1, wherein said threshold limit for said target engine speed is any one of same and different for different gear positions.

5. The controller (110) as claimed in claim 1 is at least one selected from a group comprising an Engine Control Unit (ECU) and a Transmission Control Unit (TCU).

6. A method for providing braking assistance to a vehicle (100) with an Automated Manual Transmission (AMT) (114), characterized by, said method comprising the steps of:
monitoring occurrence of triggering condition for braking assistance, and while occurrence of said triggering condition remains true;
calculating, through a controller (110), a target engine speed for a lower gear position from a current gear position, and
controlling and shifting, by said controller (110), said AMT (114) to said lower gear position when said calculated target engine speed is lower than a threshold limit.

7. The method as claimed in claim 6, wherein set condition comprises vehicle deceleration above a threshold rate, and a fully pressed brake pedal.

8. The method as claimed in claim 7, wherein said vehicle deceleration is determined using at least one of a speed sensor (102, 108), an accelerometer, and an Inertial Measurement Unit (IMU) (118), and said fully pressed brake pedal is detected using a brake pedal sensor (104).

9. The method as claimed in claim 6, wherein said threshold limit for said target engine speed is any one of same and different for different gear positions.

10. The method as claimed in claim 6, wherein said controller (110) is at least one selected from a group comprising an Engine Control Unit (ECU) and a Transmission Control Unit (TCU).
, Description: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:
The present invention relates to a controller and method to provide braking assistance to a vehicle with an Automated Manual Transmission (AMT).

Background of the invention:
An Automated Manual Transmission (AMT) vehicle is calibrated to provide a comfortable driving experience to the user which comes from the virtue of gearshift points selection based on various vehicle performance parameters. However, this approach penalizes the braking effect of vehicle coming from engine braking which is crucial especially in case of an emergency braking scenario. Typically, AMT vehicles downshift if the driver demands higher torque or the engine rpm drops below a certain value which might not be suitable for the current gear. Consequently, if driver slams the brake in panic while encountering an emergency situation or desires to stop quickly, the system will downshift based on stall rpm values and the effect of engine braking is almost negligible hence the full effect of vehicle braking capability isn’t utilized.

A patent literature US4933850 discloses a control and method for controlling AMT system including manually operated engine compression brake. A method and control for controlling an AMT system having an operator actuated engine compression brake is provided including sensing vehicle deceleration and monitoring throttle position (THL), vehicle brake actuation (BRK) and engine compression brake (ECB) actuation to select one of three mutually exclusive vehicle deceleration downshift shift profiles.

Brief description of the accompanying drawings:
An embodiment of the disclosure is described with reference to the following accompanying drawing,
Fig. 1 illustrates a block diagram of a controller to provide braking assistance to a vehicle with Automated Manual Transmission (AMT), according to an embodiment of the present invention, and
Fig. 2 illustrates a method for providing braking assistance to the vehicle with the AMT, according to the present invention.

Detailed description of the embodiments:
Fig. 1 illustrates a block diagram of a controller to provide braking assistance to a vehicle with Automated Manual Transmission (AMT), according to an embodiment of the present invention. The vehicle 100 shown is a two wheeler having an engine 116, the AMT 114 and the controller 110. The controller 110, characterized in that, configured to monitor occurrence of triggering condition for braking assistance, and while the occurrence of the triggering condition remains true, the controller 110 configured to calculate a target engine speed for a lower gear position from a current gear position. The controller 110 then controls and shifts the AMT 114 to the lower gear position when the calculated target engine speed is lower than a threshold limit.

The AMT 114 comprises the manual transmission with actuators and sensors to automate the operation of clutch and shifting of gears. The actuator is selected from a group comprising an electro-mechanical, hydraulic, pneumatic, vacuum, or electric. At least one actuator is coupled with the clutch and gearbox to automate the operation based on request from the user/driver. The controller 110 transmits the signal to the actuator for the shifting operation.

The controller 110 contains computing devices/units comprising components such as memory element 112 such as Random Access Memory (RAM) and/or Read Only Memory (ROM), Analog-to-Digital Converter (ADC), Digital-to-Analog Convertor (DAC), clocks, timers and a processor 120 (may also be capable of implementing machine learning) connected with the each other and to other components through communication bus channels. The components mentioned are just for understanding and the controller 110 may have more or less components as per requirement. The memory element 112 is pre-stored with logics or instructions or programs or applications or threshold values/limits/rate which is accessed by the processor 120 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 is capable to communicate through wired and wireless means such as but not limited to Global System for Mobile Communications (GSM), 3G, 4G, 5G, Wi-Fi, Bluetooth, Ethernet, serial networks, Universal Serial Bus (USB) cable, micro-USB, and the like. In accordance to an embodiment, the controller 110 is at least one selected from a group comprising an Engine Control Unit (ECU) and a Transmission Control Unit (TCU).

In accordance to an embodiment of the present invention, the triggering condition comprises at least one of a vehicle deceleration above a threshold rate, and a fully pressed brake pedal. The vehicle deceleration is determined using at least one of wheel speed sensor 102 for vehicle speed or engine speed sensor 108 for engine speed, an accelerometer, and an Inertial Measurement Unit (IMU) 118. The fully pressed brake pedal is detected using a brake pedal sensor 104. The accelerometer and/or the IMU 118 is either part of the vehicle 100 or external to the vehicle 100 such as in an electronic device 106 of the user, for example, smartphone, smartwatch, other wearables electronics, tablets, laptop, etc. The IMU 118 shown in the vehicle 100 is not mandatory and is just for explanation.

In accordance to an embodiment of the present invention, the threshold limit for the target engine speed is any one of same and different for different gear positions. For example, a common threshold limit is set as thcommon rpm for all the gears in the vehicle 100. Alternatively, fourth gear has th4, third gear has th3, second gear has th2 and the like. Thus, a different threshold limit (in rpm) is set for each gear in the vehicle 100.

According to the present invention, a working of the controller 110 is envisaged without any limitation to the same. Consider the vehicle 100 where engine and vehicle performance parameters (engine rpm, vehicle speed, wheel speed, current gear, gear ratios, throttle position, brake position, etc.) are measured using respective sensors comprising an engine speed sensor 108, a wheel speed sensor 102, a gear position sensor, a throttle position sensor, etc., (or estimated with basic sensors such as gear ratio is estimated using vehicle speed and engine speed without using gear position sensor) and recorded in the memory element 112. Additionally, triggering condition in the vehicle 100 is monitored in case of a braking or slowing down scenario using either wheel speeds, vehicle velocity or using an additional sensor (accelerometer or IMU 118). The triggering condition is at least one of the deceleration rate or fully pressed brake pedal. If the deceleration rate is used as the triggering condition, the triggering condition is constantly measured by the controller 110 and updated in the memory element 112. The deceleration rate is compared against a calibratable threshold rate already stored in the memory element 112 and exceeding that value, the controller 110 turns ON the braking assistance functionality.

The current engine speed translates to the upcoming engine speed for the next lower gear in the controller 110 based on below formula.
G_C/G_L =N_C/N_L

Where,
GC = Current gear ratio (including final drive ratio)
GL = Next lower gear ratio (including final drive ratio)
NC = Current engine speed
NL = Calculated engine speed for next lower gear

The above-mentioned formula is valid considering instantaneous vehicle speed remains constant. The formula is adaptable for dynamic vehicle/engine speed fluctuations as well.

For example, if engine braking assistance is enabled (during emergency braking) and the vehicle 100 is at fourth gear, the calculated engine speed (NL) for next lower gear, i.e. third gear, is determined. The engine speed NL is compared against the threshold limit, i.e. th3, which is the engine speed limiter value. If the NL is lower than threshold limit or threshold limit minus a calibration value, the controller 110 sends a downshift request to the AMT 114. The controller 110 again checks the presence of the triggering condition and the cycle continues if the triggering condition remains true, otherwise the controller 110 exists the functionality of braking assistance.

Fig. 2 illustrates a method for assisting braking in a vehicle with an AMT, according to the present invention. The method is characterized by, plurality of steps of which a step 202 comprises monitoring occurrence of triggering conditions for braking assistance, and while the occurrence of the triggering condition is detected and remains true, a step 204 followed by a step 206 are executed. The step 204 comprises calculating, through the controller 110, a target engine speed for a lower gear position from a current gear position. The step 206 comprises controlling and shifting, by the controller 110, the AMT 114 to the lower gear position when the calculated target engine speed is lower than the threshold limit. The set condition comprises vehicle deceleration above the threshold rate, and the fully pressed brake pedal.

According to the present invention, the vehicle deceleration is determined using at least one of a speed sensor 102, 108, either for vehicle speed or engine speed, the accelerometer, and the Inertial Measurement Unit (IMU) 118. The fully pressed brake pedal is detected using brake pedal sensor 104. The accelerometer and/or the IMU 118 is either part of the vehicle 100 or external to the vehicle 100 such as in the electronic device 106 of the user, for example, smartphone, smartwatch, other wearables electronics, tablets, laptop, etc. The threshold limit for the target engine speed is any one of same and different for different gear positions. Further, the controller 110 is at least one selected from a group comprising the Engine Control Unit (ECU) and the Transmission Control Unit (TCU) or other control unit interfaced with the controller 110.

According to the present invention, a detailed working of the steps 202 through 206 is envisaged for clarity and the same must not be understood in limiting manner. The method is executed by the controller 110. In step 202, the method comprises receiving signals from the sensors to detect the triggering condition. For example, the method comprises reading signal from IMU sensor 118 or wheel speed sensors 102 or vehicle speed for detecting occurrence of the deceleration rate as one of the triggering condition. Further conditions to enable assist functionality may comprise, brake input, throttle condition to be zero or below a calibration threshold, gear position to be on the higher to shift towards lower gear (gear position should be at least greater than first gear, etc. If the triggering condition is detected to have occurred, i.e. deceleration rate exists and is higher than the threshold value/rate, the method proceeds with the next steps, else the method repeatedly monitors for the occurrence of the triggering condition based input signals like vehicle speed, deceleration rate brake input and other trigger conditions, i.e. the step 202 is repeated. If the triggering condition is determined to be true, and while the triggering condition is true, the step 204 comprises reading the current gear ratio (or position), current engine speed (RPM), current vehicle speed, and determining the next lower gear ratio (position). The method comprises computing a new engine speed (RPM) based on the next determined lower gear. The step 206 comprises deciding whether the computed engine speed is below the threshold limit. If No, then the method keeps calculating the engine speed for lower gear, i.e. repeats step 204. If yes, then the method comprises downshifting the AMT 114 to the lower gear. After downshifting, the method checks for the presence of the triggering condition as done in the beginning, i.e. step 202. If yes, then the repeats the steps from the beginning, i.e. from the step 202 through to step 206. If No, then the method is complete and comes out of braking assistance functionality.

According to the present invention, the controller 110 and method provides a solution to improve braking efficiency in an Automated Mechanical Transmission (AMT) 114 based vehicle 100. The controller 110 and the method maximizes braking efficiency of the vehicle 100 by implementing a braking assistance functionality (a software logic) for utilizing maximum potential of engine braking while the vehicle 100 decelerates under heavy braking. Based on various inputs and entry conditions, the controller 110 identifies the use case and turns on software functionality which controllably downshifts the gear to stay at maximum possible engine rpm and lowest possible gear without damaging the powertrain. The vehicle 100 is provided with added deceleration rate over the achieved effect from mechanical brakes, shorter stopping distance and improved safety.

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.