WO2025201749A1

WO2025201749A1 - A controller and method for a cooperative regenerative braking system (crbs) for a two-wheeler vehicle

Info

Publication number: WO2025201749A1
Application number: PCT/EP2025/054468
Authority: WO
Inventors: Ajay SHETTY; Balakrishna DEEPAK VENKATESH; Badanidiyoor SUBRAMANYA
Original assignee: Robert Bosch GmbH; Bosch Ltd
Current assignee: Robert Bosch GmbH; Bosch Ltd
Priority date: 2024-03-29
Filing date: 2025-02-19
Publication date: 2025-10-02
Anticipated expiration: 2026-09-29

Abstract

The vehicle (100) comprises a drive motor (118), to impart driving force to the vehicle (100), which is controlled by a drive controller. The cooperative regenerative braking system (CRBS) comprises use of the drive motor (118) operable as a generator for regenerative braking, and use of the Antilock Braking System (ABS) for friction braking through friction brakes (114, 116). The device (120) comprises a controller configured to determine a required braking torque based on input from a brake pedal and vehicle speed. The controller, continuously receives, a current recuperation capacity of the drive motor (118) from the drive controller, based on the vehicle speed, characterized in that, the controller is configured to distribute the required braking torque to a first braking torque, to be applied by the friction brakes (114, 116), and a second braking torque, to be applied by the drive motor (118) through regenerative braking based on the current recuperation capacity.

Description

Title of the Invention: A CONTROLLER AND METHOD FOR A COOPERATIVE REGENERATIVE BRAKING SYSTEM (CRBS) FOR A TWOWHEELER VEHICLE

Field of the invention:

[0001] The present invention relates to a controller and method for a Cooperative Regenerative Braking System (CRBS) for a two-wheeler vehicle.

Background of the invention:

[0002] In Electric Vehicle (EV) and Hybrid Vehicle (HV) two wheelers, range anxiety with customers is a major problem, which the Original Equipment Manufacturers (OEMs) are trying to tackle. These are addressed by bigger batteries and charging infrastructure development currently. The vehicles can use motor as a generator while deceleration, to send energy back to the battery. This is called Regenerative braking. It is not exploited fully as in the case of the four wheeler counterparts, where the amount of braking can be controlled using i-Booster, Integrated Park Brake (IPB) etc.

[0003] A patent 410319 discloses a brake system for a motorcycle, method for installing a brake system on a motorcycle, and method for braking a motorcycle. The invention relates to a brake system for a motorcycle, comprising a hydraulic braking device having at least one first master brake cylinder and at least one first wheel brake cylinder, which is or can be hydraulically connected to the first master brake cylinder at least by means of a first brake circuit and can be associated with at least one first wheel in such a way that the at least one first wheel can be braked by means of the at least one first wheel brake cylinder, and an electric motor, which can be associated with at least one second wheel in such a way that at least the second wheel can be braked by means of the electric motor, wherein the electric motor can be associated with at least one wheel free of a wheel brake cylinder as the at least one second wheel. The invention further relates to a method for installing a brake system on a motorcycle. The invention further relates to a method for braking a motorcycle.

[0004] In addition to above, most of the existing cooperative braking systems or similar technologies in both four wheeler vehicles and two wheeler vehicle market uses an active brake pressure building units for Brake By Wire controller.

Brief description of the accompanying drawings:

[0005] An embodiment of the disclosure is described with reference to the following accompanying drawing,

[0006] Fig. 1 illustrates a block diagram of a device for Cooperative Regenerative Braking System (CRBS) for a two-wheeler vehicle, according to an embodiment of the present invention;

[0007] Fig. 2 illustrates a method for Cooperative Regenerative Braking System (CRBS) for the two-wheeler vehicle, according to the present invention.

Detailed description of the embodiments:

[0008] Fig. 1 illustrates a block diagram of a device for Cooperative Regenerative Braking System (CRBS) for a two-wheeler vehicle, according to an embodiment of the present invention. The vehicle 100 comprises a drive motor 118, to impart driving force to the vehicle 100, which is controlled by a drive controller (not shown). The CRBS comprises use of the drive motor 118 operable as a generator for regenerative braking (recuperation mode), and use of the Anti-lock Braking System (ABS) for friction braking through friction brakes 114, 116. The friction brakes 114, 116 are connected to brake pedal through hydraulic circuits as known in the art. The device 120 comprises a controller configured to determine a required braking torque based on input from a brake pedal and vehicle speed. The controller, continuously receives, a current recuperation capacity/potential of the drive motor 118 from the drive controller, based on the vehicle speed, characterized in that, the controller configured to calculate the torque distribution/split and distribute the required braking torque to a first braking torque, to be applied by the friction brakes 114, 116, and a second braking torque, to be applied by the drive motor 118 through regenerative braking based on the current recuperation capacity. The friction brakes 114, 116 are provided for both of a front wheel and a rear wheel. The drive motor 118 coupled to the rear wheel for regenerative braking. The term regenerative braking, regeneration and recuperation are used interchangeably and have the same meaning. The recuperation is performed in close loop manner, so that the blending of the friction braking and the regenerative braking is controlled.

[0009] According to the present invention, the controller is an ABS control unit of the vehicle 100. The ABS control unit is used as Brake-by-Wire (BBW) controller. Thus, a separate control unit is not needed, thereby reducing cost and complexity and optimizes the usage of controller. The ABS is without active pressure building of the hydraulic fluid in the hydraulic circuits. In other words, the ABS uses a passive unit which is without a motor to build up pressure in hydraulic circuits for braking.

[0010] According to the present invention, a sensor 102 is positioned in the brake pedal to determine the required braking torque. The sensor 102 is either a pressure sensor, displacement sensor or similar transducer to detect the movement of the brake pedal. Further, throttle inputs 104 and drive torque 106 are used for calculation of distribution of the required braking torque. The drive torque 106 is either due to an engine, the drive motor 118 or combination of the engine and the drive motor 118. Furthermore, a limit of the recuperation capacity is modelled using battery limits and limits of the drive motor 118. The battery limits and the limits of the drive motor 118 are dependent on the capacity and operating condition of the battery and the size and operating condition of the drive motor 118, respectively, and are used to calculate the instantaneous maximum possible recuperation.

[0011] According to the present invention, the device 120 is at least one of an internal device and an external device. The internal device is at least one Electronic Control Unit (ECU) 110 selected from a group comprising is at least one of an Engine Management System (EMS) controller, a Tire Pressure Monitoring System (TPMS) controller, a Telematics Control Unit (TCU) controller, an Anti-lock Braking System (ABS) controller, an Electronic Stability Program (ESP) controller, a Vehicle Instrument Cluster (VIC) controller, and a combination thereof. The external device is at least one of a cloud based device 108 and a communication device 112. The external device is connected through a Telematic Control Unit (TCU) of the vehicle 100 through at least one a wired and wireless means known in the art. The communication device 112 corresponds to electronic computing devices which enable a rider or driver or a user to communicate with others such as smartphone, wearable electronics such as smart watch, etc. The cloud based device 108 corresponds to cloud computing architecture having network of servers, databases connected with each other and vehicle 100 for processing of inputs and providing outputs.

[0012] According to an embodiment of the present invention, the device 120 is implementable in different manners or scenarios. In a first scenario, the device 120 is just the ECU 110 of the vehicle 100. Thus, the brake distribution is directly done by the ECU 110 of the vehicle 100. In a second scenario, the device 120 is the external device, i.e. at least one of the cloud based device 108 and the communication device 112 of the driver who drives the vehicle 100. The input signals are transmitted to the cloud based device 108 and the communication device 112 through the TCU or VIC through wired or wireless means as known in the art. The input signals are the brake pedal signal and vehicle speed. In a third scenario, the device 120 is combination of the internal device and external device, i.e. the device 120 is combination of the ECU 110 and the cloud based device 108, or combination of the ECU 110 and the communication device 112 or combination of the cloud based device 108 and the communication device 112 or the combination of the ECU 110, the cloud based device 108 and the communication device 112. The second scenario and the third scenario are explained later. [0013] The device 120 which is at least one of the ECU 110 or controller, the cloud based device 108 and the communication device 112 refers to computing devices/units comprising components such as memory element 122 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 (such as Central Processing Unit (CPU)) (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 may have more or less components as per requirement. The memory element 122 of the device 120 is prestored with map, table. Model, modules, logics, instructions, programs, applications, thresholds, or values which is accessed by the at least one processor as per the defined routines. The internal components of the controller are not explained for being state of the art, and the same must not be understood in a limiting manner. The device 120 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.

[0014] In accordance to an embodiment of the present invention and as per the second scenario, the device 120 is the external device, i.e. any one of the cloud based device 108 and the communication device 112. For ease of understanding, the device 120 is now explained as the cloud based device 108, but the same explanation is applicable when the external device is the communication device 112. When the device 120 is the cloud based device 108, the cloud based device 108 receives the input comprising the brake pedal based sensor signal and vehicle speed along with the current recuperation capacity, directly from the ECU 110. The ECU 110 does not process the input signals and directly transmits the input signal to the cloud based device 108 through the TCU or through the communication device 112. The cloud based device 108 is configured to receive the input signals from the ECU 110, determines the required braking torque and also computes the torque distribution between the first braking torque and the second braking torque for friction brakes 114, 116 and the drive motor 118. The distribution is computed to maximize/optimize the recuperation based braking and as per the limitation/capacity. The cloud based device 108 then transmits the distribution torque back to the ECU 110 of the vehicle 100, where the first braking torque is achieved through the ABS and the second braking torque is achieved through the recuperation (drive motor 118).

[0015] Similarly, when the device 120 is the communication device 112, the communication device 112 is connected to the ECU 110 through suitable communication or networking means as described before, such as but not limited to Bluetooth™, Wi-Fi, Universal Serial Bus (USB) cables, etc. The application installed in the communication device 112 processes the input signals received from the ECU 110 and sends back the result after determination or computation. Also, the application stores the result internally for later reference.

[0016] In accordance to an embodiment of the present invention and as per the third scenario, the device 120 is combination of internal device (the ECU 110) and the external device. The processing of the input signals is shared among the internal device(s) and the external device(s), and the output (distribution of torque) is finally performed in the vehicle 100. For example, consider the device 120 as combination of the ECU 110 and the cloud based device 108. The ECU 110 pre-processes the input signals (determines the required braking torque and receives the current recuperation capacity) and sends only those inputs signals (datasets) to the cloud based device 108. Now, the cloud based device 108 processes on reduced and essential number of input signals and computes the torque distribution and provides faster results back to the vehicle 100. The ECU 110 then performs the torque distribution.

[0017] Further, the vehicle 100 is any one selected from a group comprising a twowheeler such as scooter, motorcycle, and a three-wheeler such as autorickshaw which comprises the drive motor 118 for electric drive or hybrid drive. Specifically, the vehicle 100 is either internal combustion engine based or electric vehicle or hybrid vehicle. The present invention is implementable for a four wheeler such as cars, and multi -wheel vehicles 100 as well.

[0018] According to the present invention, a working of the device 120 is explained. Consider a motorcycle is used as the vehicle 100. The motorcycle is fit with ABS unit comprising ABS control unit which receives the signals from wheel speed sensors of the front wheel and rear wheel to detect slip. Further, the ABS unit comprises hydraulic circuits connecting master cylinder to brake calipers of the friction brakes 114, 116. Further, the friction brakes 114, 116 are provided for both the front wheel and the rear wheel. There is return circuit for the hydraulic fluid as well. The ABS unit is a passive unit without the presence of motor specifically for active pressure buildup in the hydraulic circuits for braking. The passive unit uses the pressure applied by the driver through the brake pedal. Furthermore, the drive motor 118 is mounted to the rear wheel. Now, whenever there is a braking scenario, the driver/rider applies pressure to the brake pedal/lever and the same is detected by the sensor 102. The controller monitors the pressure signal and the vehicle speed. At the same time, the controller has been continuously receiving the current recuperation capacity/potential of the drive motor 118 through respective drive controller. The controller computes the torque distribution based on the required braking torque and the current recuperation capacity, and blends the braking using the friction brakes 114, 116 and the regenerative braking through the drive motor 118.

[0019] Fig. 2 illustrates a method for Cooperative Regenerative Braking System (CRBS) for the two-wheeler vehicle, according to the present invention. The vehicle 100 comprises the drive motor 118, to impart driving force, which is controlled by the drive controller. The CRBS comprises use of the drive motor 118 as the generator for regenerative braking (recuperation mode), and use of the Anti- lock Braking System (ABS) for friction braking through friction brakes 114, 116. The method comprises plurality of steps of which a step 202 comprises determining, by the controller, the required braking torque based on input from the brake pedal and vehicle speed. A step 204 comprises continuously receiving, by the controller, the current recuperation capacity of the drive motor 118 from the drive controller, based on the vehicle speed. The method is characterized by a step 206 which comprises calculating the torque distribution/split and distributing, by the controller, the required braking torque to the first braking torque, to be applied by the friction brakes 114, 116, and the second braking torque, to be applied by the drive motor 118 through regenerative braking (recuperation), based on the current recuperation capacity. The friction brakes 114, 116 are provided for both of the front wheel and the rear wheel, and the drive motor 118 is coupled to the rear wheel for recuperation. The recuperation is performed in close loop manner, so that the blending of the friction braking and the regenerative braking is controlled.

[0020] The method is executed by the controller of the device 120. The device 120 at least one of the internal device and the external device. The internal device is at least one Electronic Control Unit (ECU) 110 selected from the group comprising at least one of the Engine Management System (EMS) controller, the Tire Pressure Monitoring System (TPMS) controller, the Telematics Control Unit (TCU) controller, the Anti-lock Braking System (ABS) controller, the Electronic Stability Program (ESP) controller, the Vehicle Instrument Cluster (VIC) controller, and the combination thereof. The external device is at least one of the cloud based device 108 and the communication device 112. The external device is connected through any of the Telematic Control Unit (TCU) and the Vehicle Instrument Cluster (VIC) controller of the vehicle 100 through at least one the wired and wireless means as known in the art.

[0021] According to the method, the controller is the ABS control unit of the vehicle 100. The ABS control unit is used as Brake-by-Wire (BBW) controller. The ABS is without active pressure building of the hydraulic fluid in the hydraulic circuits, i.e. ABS is a passive system. In the step 202, the sensor 102 is positioned in the brake pedal to determine the required braking torque. Further, the throttle inputs 104 and drive torque 106 is used for distribution of the required braking torque. The drive torque 106 is either due to an engine, the drive motor 118 or combination of the engine and the drive motor 118. In the step 204, the limit of the recuperation capacity/potential of the drive motor 118 is modelled using battery limits and limits of the drive motor 118. The battery limits and the limits of the drive motor 118 are dependent on the capacity and operating condition of the battery and the size and operating condition of the drive motor 118, respectively, and are used to calculate the instantaneous maximum possible recuperation.

[0022] According to the present invention, the Cooperative Regenerative Braking System (CRBS) on Electric/Hybrid two-wheeler using ABS as Brake by Wire (BBW) controller 110 is disclosed. The present invention targets range improvement by efficient use of motor regeneration and brake force. The controller and method is for the vehicle 100 with the conventional/friction brakes 114, 116 in both the wheels, i.e., the front wheel 114, and the rear wheel 116 as the recuperation or regeneration braking works different at different State Of Charge (SOC) of the battery, limits of the drive motor 118 and battery limits (age, temperature, etc.). The limits of the drive motor 118 and the battery limits are used to calculate the instantaneous max possible recuperation, which are dependent on the size and operating condition of the drive motor 118 and the capacity and operating condition of the battery. Further, recuperation is not adequate during high braking force requirements (emergency), where the blending of braking is optimized in a manner that the friction brakes 114, 116 takes over where the regenerative braking is inadequate. Due to increased range in the drive cycle due to more regenerative braking, the size of the battery pack for the same total vehicle range can be reduced. Further, the brake size can also be reduced, thereby reducing the cost. The device 120 optimizes the application of recuperation to the maximum based on the capability and optimally blends the braking between the friction braking and the regenerative braking. [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.

Claims

We claim:

1. A device (120) for a Cooperative Regenerative Braking System (CRBS) for a two-wheeler vehicle (100), said vehicle (100) comprises a drive motor (118) to impart driving force, which is controlled by a drive controller, said CRBS comprises use of said drive motor (118) as a generator for regenerative braking and use of an Anti-lock Braking System (ABS) for friction braking through friction brakes (114, 116), said device (120) comprises a controller configured to, determine a required braking torque based on input from a brake pedal and vehicle speed; continuously receive, a current recuperation capacity of said drive motor (118) from said drive controller, based on said vehicle speed, characterized in that, distribute said required braking torque to a first braking torque, to be applied by said friction brakes (114, 116), and a second braking torque, to be applied by said drive motor (118) through regenerative braking, based on said current recuperation capacity, wherein said friction brakes (114, 116) are provided for both of said front wheel and a rear wheel, and said drive motor (118) coupled to said rear wheel for recuperation.

2. The device (120) as claimed in claim 1, wherein said controller is an ABS control unit of said vehicle (100), wherein said ABS control unit is used as Brake-by-Wire (BBW) controller.

3. The device (120) as claimed in claim 1, wherein said ABS is without active pressure building of the hydraulic fluid in the hydraulic circuits.

4. The device (120) as claimed in claim 1, wherein a sensor (102) is positioned in the brake pedal to determine said required braking torque, wherein throttle inputs (104) and drive torque (106) is used for distribution of said required braking torque.

5. The device (120) as claimed in claim 1, wherein a limit of said recuperation capacity is modelled using battery limits and limits of said drive motor (118).

6. A method for a Cooperative Regenerative Braking System (CRBS) for a two-wheeler vehicle (100), said vehicle (100) comprises a drive motor (118) to impart driving force, which is controlled by a drive controller, said CRBS comprises use of said drive motor (118) as a generator for regenerative braking and use of an Anti-lock Braking System (ABS) for friction braking through friction brakes (114, 116), said method comprising the steps of, determining a required braking torque based on input from a brake pedal and vehicle speed; continuously receiving, a current recuperation capacity of said drive motor (118) from said drive controller, based on said vehicle speed, characterized by, distributing said required braking torque to a first braking torque, to be applied by said friction brakes (114, 116), and a second braking torque, to be applied by said drive motor (118) through regenerative braking, based on said current recuperation capacity, wherein said friction brakes (114, 116) are provided for both of a front wheel and a rear wheel, and said drive motor (118) coupled to said rear wheel for recuperation.

7. The method as claimed in claim 6 is an ABS control unit of said vehicle (100), wherein said ABS control unit is used as Brake-by-Wire (BBW) controller.

8. The method as claimed in claim 6, wherein said ABS is without active pressure building of the hydraulic fluid in the hydraulic circuits.

9. The method as claimed in claim 6, wherein a sensor (102) is positioned in said brake pedal to determine said required braking torque, wherein throttle inputs (104) and drive torque (106) is used for distribution of said required braking torque.

10. The method as claimed in claim 6, wherein a limit of said recuperation capacity is modelled using battery limits and limits of said drive motor (118).

Dated 11 February 2025 (Digitally signed)

Siddharth Karkhanis (IN/PA- 1195)

On-behalf of the Applicants