Claims:
1. A slip control system (101) comprising:
a slip ratio determination unit (202) configured to determine a current slip ratio associated with one or more driver wheels (102a, 102b) of a vehicle (100);
a data processing unit (206) that is coupled to the slip ratio determination unit (202), and configured to determine either a first factor or a second factor based on the current slip ratio; and
a torque regulating unit (210) that is coupled to the data processing unit (106), and configured to generate a torque regulating signal (210A) and a static signal (210B) based on the first factor and the second factor, respectively, wherein the torque regulating signal (210A) regulates a torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) and wherein the static signal (210B) keeps the torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) unchanged.

2. The slip control system (101) as claimed in claim 1, further comprising an input unit (208) that is communicatively coupled to an electronic control unit (ECU) (103) of the vehicle (100), wherein the input unit (208) is configured to provide an ECU signal received from the ECU (103) to the torque regulating unit (210) such that the torque regulating unit (210) processes the ECU signal to generate the torque regulating signal (210A) based on the first factor.

3. The slip control system (101) as claimed in claim 1, further comprising a pre-processing unit (203) that is coupled to the slip ratio determination unit (202), and configured to generate and provide a first signal to the data processing unit (206), when the current slip ratio is greater than a maximum allowable slip ratio.

4. The slip control system (101) as claimed in claim 1, wherein the pre-processing unit (203) is configured to generate and provide a second signal to the data processing unit (206), when the current slip ratio is less than or equal to the maximum allowable slip ratio.

5. The slip control system (101) as claimed in claim 3 and 4, wherein the data processing unit (206) is configured to determine the first factor and the second factor upon receipt of the first signal and the second signal from the pre-processing unit (203), respectively.

6. The slip control system (101) as claimed in claim 2, the torque regulating unit (210) is configured to reduce intensity of the ECU signal received from the input unit (208) based on the first factor determined by the data processing unit (206) to generate the torque regulating signal (210A).

7. The slip control system (101) as claimed in claim 2 and 6, the intensity of the ECU signal remains unaltered upon receipt of the second factor by the torque regulating unit (210) such that the torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) remains unchanged.

8. The slip control system (101) as claimed in claim 1, wherein to determine the current slip ratio associated with the one or more driver wheels (102) of the vehicle (100), the slip ratio determination unit (202) is configured to receive an angular speed value of the one or more driver wheels (102a, 102b) and one or more driven wheels (104a, 104b) of the vehicle (100) from a plurality of sensors (218A) associated with one or more driver wheels (102a, 102b) and the one or more driven wheels (104a, 104b) of the vehicle (100).

9. An electric vehicle (100) comprising;
one or more driver wheels (102a, 102b);
one or more electric motors (112) that are operatively coupled to each driver wheel (102) of the one or more driver wheels (102a, 102b); and
a slip control system (101) that is provided in the electric vehicle (100) such that the slip control system (101) comprising;
a slip ratio determination unit (202) configured to determine a current slip ratio associated with one or more driver wheels (102a, 102b) of a vehicle (100);
a data processing unit (106) that is coupled to the slip ratio determination unit (202), and configured to determine either a first factor or a second factor based on the current slip ratio; and
a torque regulating unit (210) that is coupled to the data processing unit (206), and configured to generate a torque regulating signal (210A) and a static signal (210B) based on the first factor and the second factor, respectively, wherein the torque regulating signal (210A) regulates a torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) and wherein the static signal (210B) keeps the torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) unchanged.

10. The electric vehicle (100) as claimed in claim 9, the slip control system (101) further comprising an input unit (208) that is communicatively coupled to an electronic control unit (ECU) (103) of the vehicle (100), wherein the input unit (208) is configured to provide an ECU signal received from the ECU (103) to the torque regulating unit (210) such that the torque regulating unit (210) processes the ECU signal to generate the torque regulating signal (210A) based on the first factor.

11. The electric vehicle (100) as claimed in claim 9, the slip control system (101) further comprising a pre-processing unit (203) that is coupled to the slip ratio determination unit (202), and configured to generate and provide a first signal to the data processing unit (206), when the current slip ratio is greater than a maximum allowable slip ratio.

12. The electric vehicle (100) as claimed in claim 11, the pre-processing unit (203) is configured to generate and provide a second signal to the data processing unit (206), when the current slip ratio is less than or equal to the maximum allowable slip ratio.

13. The electric vehicle (100) as claimed in claim 11 the data processing unit (206) is configured to determine the first factor and the second factor upon receipt of the first signal and the second signal from the pre-processing unit (203), respectively.

14. The electric vehicle (100) as claimed in claim 10, the torque regulating unit (210) is configured to reduce intensity of the ECU signal received from the input unit (208) based on the first factor determined by the data processing unit (206) to generate the torque regulating signal (210A).

15. The electric vehicle (100) as claimed in claim 10, the intensity of the ECU signal remains unaltered upon receipt of the second factor by the torque regulating unit (210) such that the torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) remains unchanged.

16. A method (300) comprising:
determining (302) a current slip ratio associated with one or more driver wheels (102a, 102b) of an electric vehicle (100) by way of a slip ratio determination unit (202);
determining (304) either a first factor or a second factor by way of a data processing unit (106) based on the current slip ratio;
generating (306) a torque regulating signal (210A) and a static signal (210B) based on the first factor and the second factor, respectively by way of a torque regulating unit (210);
regulating (308), a torque associated with the one or more driver wheels (102a, 102b) of the electric vehicle (100) by the torque regulating signal (210A); and
keeping (310), the torque associated with the one or more driver wheels (102a, 102b) of the electric vehicle (100) by the static signal (210B).

17. The method (300) as claimed in claim 16, further comprising receiving an ECU signal from an input unit (208) that is communicatively coupled to an electronic control unit (ECU) (103) of the vehicle (100); and
processing the ECU signal to generate the torque regulating signal (210A) by way of the torque regulating unit (210) based on the first factor.

18. The method (300) as claimed in claim 16, further comprising generating and providing a first signal to the data processing unit (206) by a pre-processing unit (203), when the current slip ratio is greater than a maximum allowable slip ratio.

19. The method (300) as claimed in claim 16, further comprising generating and providing a second signal to the data processing unit (206) by a pre-processing unit (203), when the current slip ratio is less than or equal to the maximum allowable slip ratio.

20. The method (300) as claimed in claim 16, further comprising determining the first factor and the second factor by the data processing unit (206) upon receipt of the first signal and the second signal from the pre-processing unit (203), respectively.

21. The method (300) as claimed in claim 16, further comprising reducing intensity of the ECU signal by the torque regulating unit (210) that is received from the input unit (208) based on the first factor determined by the data processing unit (206) to generate the torque regulating signal (210A).

22. The method (300) as claimed in claim 16, further comprising unaltering the intensity of the ECU signal upon receipt of the second factor by the torque regulating unit (210) such that the torque associated with the one or more driver wheels (102a, 102b) of the vehicle (100) remains unchanged. , Description:TECHNICAL FIELD
The present disclosure relates to electric vehicles and more particularly relates to a slip control system and method for electric vehicles.

BACKGROUND
Traction is defined as the frictional grip between the wheel and the road surface, which plays a major role in propelling the vehicle on the road. Traction of the wheel majorly depends on the continuous and reliable contact of the wheel against the road surface. While driving the vehicles there may be certain events of wheel slipping which can be caused due to improper traction between the wheel and the road surface. Variation in the road surface and driving characteristics i.e., application of irregular accelerative forces to the wheel, varies the tractive force associated with the wheel. This variation in traction force causes the excessive driving force to overcome the frictional grip or static friction between the road surface and the wheel and eventually causes wheel slipping. The excessive driving force (torque) causes rotation of the wheel at a higher surface speed than the forward travel velocity (translational velocity) of the vehicle.
During slippage condition of the wheels, the drivers have less control of the speed and direction associated with the vehicle. Before taking any corrective action with regards to slippage, the driver must be sure that the slippage condition has arrived and accordingly decide for corrective actions to control the slippage. While controlling the slippage, the drivers usually get limited time to take or decide on the corrective action, which causes inability for the drivers to act appropriately. For sake of controlling the slippage effect on the wheels, the drivers attempt to reduce the speed of the driving wheel to maintain appropriate traction between the wheels and the road. For this, the drivers either need to ease down the throttle or to apply brakes on the wheels. The choice for the control measures to control the slippage is based on the acceleration or other driving conditions and road surface. Majorly, the braking torque is applied on the motor in order to limit the driving torque of the motor, which leads to inefficient utilization of torque generated by the engine and making sometimes difficult to attain back the required amount of driving force for the wheels. For light electric vehicles that need less amount of torque to propel the vehicle, this effect of braking torque for controlling slippage becomes substantial.
In an attempt to yield the compatibility of driving and acceleration performance, regardless of driving loads on a vehicle, a system and method to control the wheel slippage is desired.

SUMMARY
In view of the foregoing, a slip control system is provided, the slip control system including a slip ratio determination unit configured to determine a current slip ratio associated with one or more driver wheels of a vehicle. A data processing unit that is coupled to the slip ratio determination unit, and configured to determine either a first factor or a second factor based on the current slip ratio and a torque regulating unit that is coupled to the data processing unit, and configured to generate a torque regulating signal and a static signal based on the first factor and the second factor, respectively, such that the torque regulating signal regulates a torque associated with the one or more driver wheels of the vehicle and the static signal keeps the torque associated with the one or more driver wheels of the vehicle unchanged. An input unit that is communicatively coupled to an electronic control unit (ECU) of the vehicle, such that the input unit is configured to provide a signal received from the ECU to the torque regulating unit such that the torque regulating unit processes the signal to generate the torque regulating signal based on the first factor.
In some aspects, the slip control system further includes a pre-processing unit that is coupled to the slip ratio determination unit, and configured to generate and provide a first signal to the data processing unit, when the current slip ratio is greater than a maximum allowable slip ratio. The pre-processing unit is configured to generate and provide a second signal to the data processing unit, when the current slip ratio is less than or equal to the maximum allowable slip ratio. The data processing unit is configured to determine the first factor and the second factor upon receipt of the first signal and the second signal from the pre-processing unit, respectively. The intensity of the ECU signal remains unaltered upon receipt of the second factor by the torque regulating unit such that the torque associated with the one or more driver wheels of the vehicle remains unchanged. To determine the current slip ratio associated with the one or more driver wheels of the vehicle, the slip ratio determination unit is configured to receive an angular speed value of the one or more driver wheels and one or more driven wheels of the vehicle from a plurality of sensors associated with one or more driver wheels and the one or more driven wheels of the vehicle.
Another aspect of the present disclosure provides an electric vehicle. The electric vehicle includes one or more driver wheels, one or more electric motors that are operatively coupled to each driver wheel of the one or more driver wheels and a slip control system that is provided in the electric vehicle such that the slip control system including. A slip ratio determination unit configured to determine a current slip ratio associated with one or more driver wheels of a vehicle. A data processing unit that is coupled to the slip ratio determination unit, and configured to determine either a first factor or a second factor based on the current slip ratio and a torque regulating unit that is coupled to the data processing unit, and configured to generate a torque regulating signal and a static signal based on the first factor and the second factor, respectively, such that the torque regulating signal regulates a torque associated with the one or more driver wheels of the vehicle and the static signal keeps the torque associated with the one or more driver wheels of the vehicle unchanged.
In another aspect, a method for controlling slip of the driver wheel of the vehicle is provided. The method including determining a current slip ratio associated with one or more driver wheels of an electric vehicle by way of a slip ratio determination unit, determining either a first factor or a second factor by way of a data processing unit based on the current slip ratio, generating a torque regulating signal and a static signal based on the first factor and the second factor, respectively by way of a torque regulating unit, regulating a torque associated with the one or more driver wheels of the electric vehicle by the torque regulating signal, and keeping the torque associated with the one or more driver wheels of the electric vehicle by the static signal.

BRIEF DESCRIPTION OF DRAWINGS
The above and still further features and advantages of embodiments of the present invention becomes apparent upon consideration of the following detailed description of embodiments thereof, especially when taken in conjunction with the accompanying drawings, and wherein:
FIG. 1 illustrates an electric vehicle incorporated with a slip control system, according to an embodiment herein;
FIG. 2A illustrates a block-diagram of the slip control system of FIG. 1, according to an embodiment herein;
FIG. 2B illustrates a block diagram of a slip ratio determination unit of FIG. 2A, according to an embodiment herein; and
FIG. 3 illustrates a method for reducing slip of a driver wheel of a vehicle, according to an embodiment herein.
To facilitate understanding, like reference numerals have been used, where possible, to designate like elements common to the figures.

DETAILED DESCRIPTION OF THE DRAWINGS
Various embodiment of the present invention provides a slip control system and method. The following description provides specific details of certain embodiments of the invention illustrated in the drawings to provide a thorough understanding of those embodiments. It should be recognized, however, that the present invention can be reflected in additional embodiments and the invention may be practiced without some of the details in the following description.
The various embodiments including the example embodiments are now described more fully with reference to the accompanying drawings, in which the various embodiments of the invention are shown. The invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete, and fully conveys the scope of the invention to those skilled in the art. In the drawings, the sizes of components may be exaggerated for clarity.
It is understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it can be directly on, connected to, or coupled to the other element or layer or intervening elements or layers that may be present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “top,” “bottom,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It is to be understood that the spatially relative terms are intended to encompass different orientations of the structure in use or operation in addition to the orientation depicted in the figures.
Embodiments described herein refer to plan views and/or cross-sectional views by way of ideal schematic views. Accordingly, the views may be modified depending on simplistic assembling or manufacturing technologies and/or tolerances. Therefore, example embodiments are not limited to those shown in the views but include modifications in configurations formed on basis of assembling process. Therefore, regions exemplified in the figures have schematic properties and shapes of regions shown in the figures exemplify specific shapes or regions of elements, and do not limit the various embodiments including the example embodiments.
The subject matter of example embodiments, as disclosed herein, is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different features or combinations of features similar to the ones described in this document, in conjunction with other technologies. Generally, the various embodiments including the example embodiments relate to slip control systems and methods.
As mentioned there remains a need for providing a slip control system and method for a vehicle that is capable to regulate a torque associated with a wheel of the vehicle without wasting the torque. Accordingly, the present disclosure provides a slip control system and method.
The term “driver wheel” as used herein the context of the present disclosure is a wheel of a vehicle that is equipped with an electric motor or any other driving means providing necessary torque to the wheel.
The term “driven wheel” as used herein the context of the present disclosure is a wheel of a vehicle that is not equipped with an electric motor or any other driving means and is rotated by being a part of the vehicle.
The term “slip ratio” as used herein the context of the present disclosure is a means of calculating and expressing the slipping behavior of an associated wheel of an automobile for which the term is used.
The term “predefined desired slip ratio” as used herein the present disclosure means is the slip ratio value that is desired to be exhibited by the driver wheel of the vehicle in order to have an appropriate traction between the road surface and the driver wheel. Further, the term “predefined desired slip ratio” is interchangeably used with the term “desired slip ratio” herein the context of the present disclosure.
The term “predefined maximum allowable slip ratio” as used herein the present disclosure is the maximum value of the slip ratio that can be achieved and beyond such value, the wheels of the vehicle may get slip with respect to the surface of the road. Further, the term “predefined maximum allowable slip ratio” is interchangeably used with the term “maximum allowable slip ratio” herein the context of the present disclosure.
The term “ECU signal” as used herein the present disclosure is the signal received from the electronic control unit (ECU) of the vehicle by the input unit of the slip control system.
The term “intensity” associated with any of the signal as used herein the present disclosure may be the magnitude of the signal, which may be measured in terms of amplitude or frequency of the signal. Upon varying the intensity of the signal, the signal gets manipulated and thereby varying the effect of the signal.
The terms “vehicle” and “electric vehicle” are interchangeably used herein the present disclosure.
FIG. 1 illustrates an electric vehicle (100), according to an embodiment of the present disclosure. The electric vehicle (100) may include a slip control system (101), a plurality of driver wheels (referred to as “driver wheel” for single component) (102a, 102b), a plurality of driven wheels (referred to as “driven wheel” for single component) (104a, 104b), an electronic control unit (ECU) (103), and an electric motor (112).
The slip control system (101) may be operatively coupled to the plurality of driver wheels (102a, 102b). The electric motor (112) may be internal to the plurality of the driver wheels (102a, 102b).
The electric motor (112) may be adapted to provide necessary torque to the plurality of the driver wheels (102a, 102b). The slip control system (101) may be adapted to control slippage associated with the plurality of the driver wheels (102a, 102b). The slip control system (101) may be adapted to control slippage of the plurality of driver wheels (102a, 102b) by regulating the torque produced by the electric motor (112) and consequently regulating the torque associated with the plurality of driver wheels (102a, 102b). The slip control system (101) therefore may be adapted to control traction (tractive force) between the plurality of driver wheels (102a, 102b) and a road surface (not shown) on which the vehicle (100) is moving.
In some embodiments, the electric motor (112) may be operatively coupled to the plurality of the driver wheels (102a, 102b).
In some embodiments, the driver wheel (102) may include more than one electric motor (112). In some embodiments, the slip control system (101) may be coupled with more than one driver wheels of the plurality of the driver wheels (102a, 102b) in order to control slippage associated with the driver wheel (102).
In some embodiments, the electric vehicle (100) may be a two-wheeler such that one wheel (e.g., rear wheel) of the two-wheeler may be the driver wheel and another wheel (e.g., front wheel) of the two-wheeler may be the driven wheel (104).
In another embodiment, the electric vehicle (100) may be provided with all of the wheels as the driver wheel (102).
FIG. 2A illustrates a block diagram of the slip control system (101). The slip control system (101) includes a slip ratio determination unit (202), a pre-processing unit (203), a computation unit (204), a data processing unit (206), an input unit (208), and a torque regulating unit (210).
The slip ratio determination unit (202) may be communicatively coupled to the pre-processing unit (203). The computation unit (204) may be communicatively coupled to the pre-processing unit (203). The pre-processing unit (203) may be communicatively coupled to the data processing unit (206). The ECU (103) of the vehicle (100) may be communicatively coupled to the input unit (208) and the input unit (208) may be communicatively coupled to the torque regulating unit (210). The data processing unit (206) may be communicatively coupled to the torque regulating unit (210). The torque regulating unit (210) may be communicatively coupled to the electric motor (112) of the driver wheel (102) of the electric vehicle (100).
In an embodiment, the data processing unit (206) may be any or a combination of microprocessor, microcontroller, Arduino Uno, At mega 328, Raspberry Pi or other similar processing unit, and the like. In yet another embodiment, the data processing unit (206) may include one or more processors coupled with a memory (not shown) such that the memory storing computer-readable instructions executable by the one or more processors.
In some embodiments, the data processing unit (206) may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions stored in a memory. The computer-readable instructions or routines stored in the memory may be fetched and executed to create or share the data units over a network service. The memory may include any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.
In some embodiments, the data processing unit (206) may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the data processing unit (106). In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the data processing unit (206) may be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the data processing unit (206) may include a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the data processing unit (206). In such examples, the data processing unit (206) may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the data processing unit (206) and the processing resource. In other examples, the data processing unit (206) may be implemented by an electronic circuitry.
The ECU (103) of the electric vehicle (100) may be adapted to transmit an ECU signal (not shown) to the input unit (208) of the slip control system (101). The input unit (208) may be adapted to transmit the ECU signal to the torque regulating unit (210).
In some embodiments, the ECU signal transmitted from the ECU (103) to the input unit (208) may include, but is not limited to, a pulse-width modulated (PWM) signal, an analog signal, a digital signal, and the like. Embodiments of the present disclosure are intended to include and/or otherwise cover any type of the ECU signal, known to a person of ordinary skill in the art.
In some embodiments, the vehicle (100) may be a two-wheeler such that a throttle input block of the two-wheeler may be adapted to transmit the ECU signal to the input unit (208) of the slip control system (101).
In operation, an appropriate circuitry of the slip ratio determination unit (202) may be adapted to perform one or more operations, for example to determine a current slip ratio associated with the driver wheel (102) of the vehicle (100). The current slip ratio associated with the driver wheel (102) of the vehicle (100) is the actual slip ratio associated with the driver wheel (102) of the electric vehicle (100). The current slip ratio for the driver wheel (102) depends on the torque produced by the electric motor (112) of the driver wheel (102), characteristics of road surface on which the vehicle (100) is moving and characteristics of the driver wheel (102) of the vehicle (100). In an embodiment, the characteristics of the driver wheel (102) of the electric vehicle may include a tire tread pattern, tire wear, duration of the tire being employed in the vehicle, and tire material.
An appropriate circuitry of the computation unit (204) may be adapted to perform one or more operations, for example to store a predefined maximum allowable slip ratio and a predefined desired slip ratio associated with the driver wheel (102) of the vehicle (100). The predefined maximum allowable slip ratio and the predefined desired slip ratio depends on the torque produced by the electric motor (112) of the driver wheel (102), characteristics of road surface on which the vehicle (100) is moving and characteristics of the driver wheel (102) of the vehicle (100). The computation unit (204) may further be adapted to compare the current slip ratio for the driver wheel (102) with the predefined maximum allowable slip ratio.
In some embodiments, the computation unit (204) may be adapted to dynamically compute the predefined maximum allowable slip ratio and the predefined desired slip ratio based on the road surface and characteristics of the driver wheel (102) of the vehicle (100).
An appropriate circuitry of the pre-processing unit (203) may be adapted to perform one or more operations, for example to generate a first signal and a second signal. The pre-processing unit (203) may be adapted to generate the first signal, when the current slip ratio may be greater than the maximum allowable slip ratio as compared by the computation unit (204). The pre-processing unit (203) may be adapted to generate the second signal, when the current slip ratio may be less than or equal to the maximum allowable slip ratio as compared by the computation unit (204). Upon generation of either the first signal or the second signal based on the comparison of the current slip ratio with the maximum allowable slip ratio, the pre-processing unit (203) may be adapted to transmit the first signal or the second signal to the data processing unit (206).
An appropriate circuitry of the data processing unit (206) may be adapted to perform one or more operations, for example to generate a first factor and a second factor. The data processing unit (206) may be adapted to generate the first factor upon receipt of the first signal transmitted by the pre-processing unit (203) and to generate the second factor upon receipt of the second signal transmitted by the pre-processing unit (203). The data processing unit (206) may be adapted to determine the first factor by using the following methodology: -
The current slip ratio may be subtracted from the predefined desired slip ratio to calculate an error value. Since, the first factor may only be determined, when the current slip ratio is greater than the maximum allowable slip ratio and the value of the desired slip ratio is less than the predefined maximum allowable slip ratio. Therefore, upon subtracting the determined current slip ratio from the predefined desirable slip ratio would give a negative error value. This negative error value may be then added to one “1” for computing an unsaturated scaling factor. The unsaturated scaling factor may be converted into the first factor. The value of the first factor may lie between 0 and 1 (including both “0” and “1”). This way the data processing unit (206) may be adapted to determine the first factor, when the determined current slip ratio is greater than the maximum allowable slip ratio.
The torque regulating unit (210) may be adapted to process the ECU signal received from the input unit (208) based on the first factor and the second factor as determined by the data processing unit (206). The torque regulating unit (210) may be adapted to generate a torque regulating signal (210A) by processing the ECU signal based on the first factor determined by the data processing unit (206). In order to generate the torque regulating signal (210A), the torque regulating unit (210) may be adapted to reduce intensity of the ECU signal received from the input unit (208). The torque regulating signal (210A) may be transmitted to the electric motor (212) of the plurality of driver wheels (102a, 102b). The torque regulating signal (210A) may be adapted to regulate the torque produced by the electric motor (112) and consequently regulating the torque associated with the driver wheel (102) of the vehicle (100). The torque regulating unit (210) may be adapted to generate a static signal (110B) by processing the ECU signal based on the second factor determined by the data processing unit (206). In order to generate the static signal (210B), the intensity of the ECU signal remains unaltered by the torque regulating unit (210). The static signal (210B) may be transmitted to the electric motor (112) of the plurality of the driver wheels (102a, 102b). The static signal (210B) may be adapted to keep the torque produced by the electric motor (112) unchanged and, therefore: the torque associated with the plurality of the driver wheels (102a, 102b) remains unaltered. In this scenario the vehicle (100) may be stable enough while traversing on the road and the static signal (210B) may directly pass through the electric motor (212) without affecting the torque produced by the electric motor (212).
In an embodiment, the slip control system (101) may be operatively coupled to each driver wheel of the plurality of driver wheels (102a, 102b) of the electric vehicle (100) for regulating the torque associated with each of the driver wheels (102).
In an embodiment, the determined current slip ratio is substantially larger than the maximum allowable slip ratio such that the value of the unsaturated scaling factor becomes negative. The first factor becomes “0” due to negative value of the unsaturated scaling factor. The “0” value of the first factor cuts off the torque of the electric motor (112) for a very short period of time and thereby regulating the torque of the electric motor (112). In an exemplary embodiment, the determined current slip ratio is 70% larger than the maximum allowable slip ratio such that the first factor becomes “0” due to negative value of the unsaturated scaling factor.
In an embodiment, the determined current slip ratio is slightly larger than the maximum allowable slip ratio such that the value of the unsaturated scaling factor lies between “0” and “1”. The value of the unsaturated scaling factor lying between “0” and “1” generates the torque regulating torque signal (210A) for regulating the torque of the electric motor (112) appropriately and thereby maintaining the determined current slip ratio under the maximum allowable slip ratio. In an exemplary embodiment, the determined current slip ratio is 30% to 70% larger than the maximum allowable slip ratio such that the first factor lies between “0” and “1”.
In some embodiments, the slip control system (101) may be operatively coupled to one of the driver wheels of the plurality of the driver wheels (102a, 102b).
FIG. 2B illustrates a block diagram of the slip ratio determination unit (202) of the slip control system (101) for determining current slip ratio associated with the driver wheel (102) of the vehicle (100). The slip ratio determination unit (202) may include a theoretical speed determination unit (114), an actual speed determination unit (216), a sensor transmitter unit (218), and a saturation unit (220).
The actual speed determination unit (216) further includes a micro-controller (216A).
The sensor transmitter unit (218) further includes a plurality of sensors (218A) and a transmitter (218B). The plurality of sensors (218A) may be deployed with the driver wheel (102) and the driven wheel (104) of the vehicle (100).
The theoretical speed determination unit (214) may be adapted to perform one or more than one functions such as determining a theoretical speed value of the vehicle (100). The theoretical speed value of the vehicle (100) may be determined by the theoretical speed determination unit (214) by determining an angular speed of a rim of the driver wheel (102) or the driven wheel (104) and rolling radius of the driver wheel (102) or the driven wheel (104). Since, determining the actual speed value of the vehicle (100) is difficult, therefore: it is assumed that a driven wheel (104) of the vehicle (100) exhibit zero slippage and is perfectly rolling on the road. The plurality of sensors (218A) of the sensor transmitter unit (218) may be adapted to measure the angular speed value of the driver wheel (102) and the driven wheel (104) of the vehicle (100). The angular speed value associated with the driver wheel (102) and the driven wheel (104) may be transmitted to the actual speed determination unit (216) by the transmitter (218B). The micro-controller (216A) of the actual speed determination unit (216) receives the measured angular speed values of the driver wheel (102) and the driven wheel (104) from the transmitter (218B) to determine an actual speed value of the vehicle (100). The current slip ratio associated with the driver wheel (102) of the vehicle (100) may be determined by expressing the difference between the theoretical speed value of the vehicle (100) and the actual speed value of the vehicle (100) as the percentage of the actual speed value of the vehicle (100). The saturation unit (220) may be adapted to prevent division of the difference value of the theoretical speed value of the vehicle (100) and the actual speed value of the vehicle (100) by zero, while determining the current slip ratio associated with the driver wheel (102) of the vehicle (100).
FIG. 3 illustrates a flowchart of a method (300) for reducing slip of the driver wheel (102) of the electric vehicle (100).
At step (302), the slip control system (101) determines the current slip ratio associated with the driver wheel (102) of the electric vehicle (100) by the slip ratio determination unit (202). Since, the current slip ratio associated with the driver wheel (102) may be expressed as the different between the theoretical speed value of the vehicle (100) and the actual speed value of the vehicle (100) as the percentage of the actual speed value of the vehicle (100), therefore: the slip ratio determination unit (202) may be adapted to determine the theoretical speed value and the actual speed value of the vehicle (100) in a manner as explained in detail hereinabove.
At step (303), the slip control system (101) compares the current slip ratio for the driver wheel (102) with the predefined maximum allowable slip ratio by way of the computation unit (204).
At step (304), the slip control system (101) determines either the first factor, when the current slip ratio is greater than the maximum allowable slip ratio or the second factor, when the current slip ratio is lesser than or equal to the maximum allowable slip ratio by way of the data processing unit (206) that is communicatively coupled to the slip ratio determination unit (202). The first factor may be determined by the data processing unit (206) The data processing unit (206) may be adapted to determine the first factor by using the following methodology: -
The determined current slip ratio may be subtracted from the predefined desired slip ratio to calculate an error value. Since, the slip control system (101) may only be activated when the determined current slip ratio is greater than the maximum allowable slip ratio and the value of the desired slip ratio is less than the predefined maximum allowable slip ratio. Therefore, upon subtracting the determined current slip ratio from the predefined desirable slip ratio would give a negative error value. This negative error value may be then added to one “1” for computing an unsaturated scaling factor. The unsaturated scaling factor may be converted into the first factor. The value of the first factor may lie between 0 and 1 (including both “0” and “1”). This way the data processing unit (206) may be adapted to determine the first factor, when the determined current slip ratio is greater than the maximum allowable slip ratio.
At step (306), the slip control system (101) generates the torque regulating signal (210A) and the static signal (210B) by way of the torque regulating unit (210) that may be coupled to the data processing unit (206) such that the torque regulating signal (210A) may be generated based on the first factor and the static signal (210B) may be generated based on the second factor. The input unit (208) may be adapted to transmit the ECU signal received from the ECU (103) of the electric vehicle (100) to the torque regulating unit (210). In order to generate the torque regulating signal (110A), the torque regulating unit (210) may be adapted to reduce intensity of the ECU signal received from the input unit (208). In order to generate the static signal (210B), the intensity of the ECU signal remains unaltered by the torque regulating unit (210).
At step (308), the slip control system (101) regulates the torque associated with the driver wheel (102) of the electric vehicle (100) by supplying the torque regulating signal (210A) generated by the torque regulating unit (210) at the step 306, to the electric motor (112) coupled to the driver wheel (102) of the electric vehicle (100).
At step (310), the slip control system (101) keeps the torque produced by the electric motor (112) unchanged by supplying the static signal (210B) generated by the torque regulating unit (210) at the step 306, to the electric motor (112) of driver wheel (102) of the vehicle (100). By virtue of the static signal (210B) the torque associated with the plurality of the driver wheels (102a, 102b) remains unaltered. In this scenario the vehicle (100) may be stable enough while traversing on the road and the static signal (210B) may directly pass through the electric motor (112) without affecting the torque produced by the electric motor (112).
Certain advantages of the slip control system (101) of the present disclosure are listed hereinbelow: -
- The slip control system (101) facilitates better handling characteristics for the vehicle (100).
- The slip control system (101) enables optimized utilization of the torque produced by the electric motor (112) of the vehicle (100).
- The slip control system (101) makes riding of electric bikes easier and safer by preventing slippage of the plurality of driver wheels (102a, 102b) and the plurality of driven wheels (104a, 104b) and hence aiding the driver to manoeuvre the electric bike or the vehicle (100) in slippery conditions.
- The slip control system (101) mitigates the slip of the plurality of the driver wheels (102a, 102b), therefore: the slip control system (101) enables faster acceleration for the vehicle (100) and eventually reduces the energy consumption while driving the vehicle (100).
The foregoing discussion of the present disclosure has been presented for purposes of illustration and description. It is not intended to limit the present invention to the form or forms disclosed herein. In the foregoing Detailed Description, for example, various features of the present invention are grouped together in one or more embodiments, configurations, or aspects for the purpose of streamlining the disclosure. The features of the embodiments, configurations, or aspects may be combined in alternate embodiments, configurations, or aspects other than those discussed above. This method of disclosure is not to be interpreted as reflecting an intention the present invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment, configuration, or aspect. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of the present invention.
Moreover, though the description of the present disclosure has included description of one or more embodiments, configurations, or aspects and certain variations and modifications, other variations, combinations, and modifications are within the scope of the present invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments, configurations, or aspects to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.