GB2566507B

GB2566507B - Spin-control system and method of performing spin-control for electrical vehicles

Info

Publication number: GB2566507B
Application number: GB1714905.5A
Authority: GB
Inventors: lam Albert
Original assignee: Detroit Electric EV Technologies Zhejiang Ltd
Current assignee: Detroit Electric EV Technologies Zhejiang Ltd
Priority date: 2017-09-15
Filing date: 2017-09-15
Publication date: 2019-10-16
Anticipated expiration: 2037-09-15
Also published as: GB201714905D0; GB2566507A

Description

SPIN-CONTROL SYSTEM AND METHOD OF PERFORMING SPIN-CONTROL FOR ELECTRICAL VEHICLES

TECHNICAL FIELD

The present disclosure relates generally to traction control in electrical vehicles, and specifically to a spin-control system for an electrical vehicle. Moreover, the present disclosure is concerned with method of performing spin-control for an electrical vehicle.

BACKGROUND

In recent years, advances in batteries and energy management technologies, concerns about increasing oil prices, and a need to reduce greenhouse gas emissions, have led to an unprecedented boost in manufacture of electrical vehicles. Typically, such electrical vehicles include performance vehicles which support large motors and provide brisk accelerations when in operation, for example, an acceleration performance from 0 km/hour to 100 km/hour within 5 seconds. For several reasons, most performance vehicles rely on a rear wheel drive (RWD), because it is difficult to cope with transmitting large drive-train torque simultaneously with providing for steering. Rear wheel drive (RWD) offers a better initial acceleration, because weight is transferred to a rear portion of a given electrical vehicle upon accelerating, thus boosting traction. Additionally, by keeping a part of a drivetrain in a rear of a given electrical vehicle, such a rear wheel drive (RWD) usually results in an optimal weight distribution, improving the given vehicle's overall balance and handling.

However, a significant disadvantage of rear wheel drive (RWD) vehicles is that they are more susceptible to spinning due to loss of traction on slippery surfaces, such as wet or muddy roads, black ice or loose gravel. It is well known that while driving a rear wheel drive (RWD) vehicle, it is feasible to control and recover from a spin by applying breaks and steering the vehicle in the intended direction of the vehicle. Such manual means depend greatly on the driver's skill, experience, and perception. For these reasons, use of rear wheel drive (RWD) vehicles may not be preferred in unfavorable conditions, for example when driving in aforementioned slippery surfaces and at high speeds. Moreover, even with modern traction control capabilities, rear wheel drive (RWD) vehicles remain prone to spinning out of control due to loss of traction.

Therefore, in light of the foregoing discussion, there exist problems associated with spin-control of electrical vehicles.

SUMMARY

The present disclosure seeks to provide an improved spin-control system for an electrical vehicle.

The present disclosure also seeks to provide an improved method of spin-control for an electrical vehicle.

According to a first aspect, an embodiment of the present disclosure provides a spin-control system for an electrical vehicle, wherein the electrical vehicle comprises a vehicle frame, a battery arrangement for storing energy, a power control arrangement for controlling an electrical power flow between the battery arrangement and an electrical motor arrangement, wherein the electrical motor arrangement is operable to drive one or more rear wheels of the electrical vehicle, characterized in that: (i) the spin-control system comprises an angular sensor for sensing an angular orientation of the electrical vehicle about a vertical axis through a center of gravity of the electrical vehicle relative to an intended direction of the electrical vehicle, to provide an angle and/or angular turning rate signal (ii) the spin-control system comprises of at least one torque sensor which is operatively coupled to at least one of the rear wheels for determining torque associated with the at least one of the rear wheels for detecting loss of traction thereof, (iii) the spin-control system is operable to apply a retarding force and/or a reverse rotation to one or more of the rear wheels of the electrical vehicle when the angle and/or angular turning rate signal exceeds a threshold value wherein the threshold value is varied dynamically as the vehicle recovers from a given spin, and (iv) the spin control system operates iteratively to drive a rear wheel in reverse or to apply a rotation retarding force to the rear wheel, such operation being in respect of one or more of the rear wheels and being dependent upon the change in the angle and/or in the angular turning rate associated with the preceding iterative operation.

The improved spin-control system provides an efficient spin-control of electrical vehicles, especially on slippery (slick) surfaces, such as wet or muddy roads, black ice or loose gravel; the spin-control is performed efficiently based upon sensing of the angular sensor.

According to a second aspect, an embodiment of the present disclosure provides a method of performing spin-control for an electrical vehicle, wherein the electrical vehicle comprises a vehicle frame, a battery arrangement for storing energy, a power control arrangement for controlling an electrical power flow between the battery arrangement and an electrical motor arrangement, wherein the electrical motor arrangement is operable to drive one or more rear wheels of the electrical vehicle, characterized in that the method comprises: (i) using an angular sensor for sensing an angular orientation of the electrical vehicle about a vertical axis through a center of gravity of the electrical vehicle relative to an intended direction of the electrical vehicle, to provide an angle and/or angular turning rate signal; (ii) using at least one torque sensor which is operatively coupled to at least one of the rear wheels for determining torque associated with the at least one of the rear wheels for detecting loss of traction thereof, (iii) applying a retarding force and/or reverse rotation to one or more of the rear wheels of the electrical vehicle when the angle and/or angular turning rate signal exceeds a threshold value wherein the threshold value is varied dynamically as the vehicle recovers from a given spin, and (iv) operating the spin control system iteratively to drive a rear wheel in reverse or to apply a rotation retarding force to the rear wheel, such operation being in respect of one or more of the rear wheels and being dependent upon the change in the angle and/or in the angular turning rate associated with the preceding iterative operation.

It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.

The present invention is included in the general business context, which aims to substitute vehicles powered by traditional fuels, for example gasoline or diesel, by electric vehicles. In particular, the present invention is intended for use in electric vehicles used within cities, which can be highly beneficial to the local environment due to significant reduction of gaseous emissions as well as significant reduction of noise. Overall environmental benefits can also be significant when electric vehicles are charged from renewable energy sources.

DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.

Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein: FIG. 1 is a schematic illustration of an electrical vehicle having a spin-control system, in accordance with an embodiment of the present disclosure; and FIG. 2 is an illustration of steps for a method of performing spin-control for an electrical vehicle, in accordance with an embodiment of the present disclosure.

In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

DESCRIPTION OF EMBODIMENTS

In overview, embodiments of the present disclosure are concerned with a spin-control system for electrical vehicles, and specifically, for rear wheel driven electrical vehicles. The spin-control system operates by at least one of: (a) momentarily driving the rear wheels in reverse; and (b) applying a rotation retarding (drag) force to the rear wheels.

Optionally, the spin-control system employs (a) or (b), or a combination of (a) and (b); for example, the spin-control system switches temporally between (a) and (b) depending upon temporal properties of the angle and/or angular turning rate signal for the spin-control system. Optionally, in an event that the electrical vehicles have independently-controllable electrical motors for each of the rear wheels of the electrical vehicles, momentary reversing and/or retarding of the rear wheels are applied in a mutually different manner to each of the rear wheels.

Referring to FIG. 1, shown is a schematic illustration of an electrical vehicle 100 having a spin-control system 102, in accordance with an embodiment of the present disclosure. As shown, the electrical vehicle 100 comprises a vehicle frame 104, a battery arrangement 106 for storing energy, a power control arrangement 108 for controlling an electrical power flow between the battery arrangement 106 and an electrical motor arrangement 110. The electrical motor arrangement 110 is operable to drive one or more rear wheels 112 of the electrical vehicle 100. Optionally, the electrical motor arrangement 110 is implemented as a single electrical motor that is coupled via a differential gear to the one or more rear wheels 112. Alternatively, the electrical motor arrangement 110 is implemented as a plurality of electrical motors, for example two electrical motors, that is coupled to their respective rear wheels 112.

In an embodiment, the vehicle frame 104 may include a body frame, a chassis, doors and the like. In an embodiment, the battery arrangement 106 may be configured to provide electrical power to the electrical motor arrangement 110. Furthermore, the electrical motor arrangement 110 may be used to provide motive power to the electrical vehicle 100 through its rear wheels 112, as aforementioned.

According to an embodiment, the present disclosure applies to rear wheel driven (RWD) vehicles, such as the electrical vehicle 100 driven by the rear wheels 112 with the help of electrical motor arrangement 110. In an embodiment, as aforementioned, the electrical motor arrangement 110 includes a single electrical motor operable to drive the rear wheels 112 via a driveshaft 120 linked to a rear axle 122 by a rear differential 124. Alternatively, the electrical motor arrangement 110 may comprise multiple motors, i.e. individual motors operatively coupled each to the rear wheels 112. In one embodiment, the electrical motor arrangement 110 comprises one or more hub motors mounted into the rear wheels 112 of the electrical vehicle 100. In such an embodiment, the one or more rear wheels 112 mounted with hub motors may be controlled independently, and may be driven at mutually varying rates by the power control arrangement 108.

The spin-control system 102 includes an angular sensor 130 for sensing an angular orientation of the electrical vehicle 100 to provide an angle and/or angular turning rate signal for the spin-control system. The spin-control system 102 is operable to prevent the electrical vehicle 100 from going into spin due to loss of traction at high speeds and/or slippery (slick) surfaces, such as wet or muddy roads, black ice or loose gravel. The spin-control system 102 relies on the angular sensor 130 for sensing the angular orientation 0of the electrical vehicle 100 about a vertical axis through its center of gravity. Furthermore, based upon the sensed angular orientation Θ, the spin-control system 102 provides an angle and/or angular turning rate signal which represents the rate of angular rotation of the electrical vehicle 100 about the vertical axis. Additionally, the angle and/or angular turning rate signal, in reference to the speed of the vehicle, indicates whether or not the electrical vehicle 100 is in a condition of excessive spin.

Optionally, the angular sensor 130 is implemented using at least one of: a resonating Coriolis sensor, an optical gyroscopic sensor, a ring-laser gyro, a differential accelerometer arrangement. Generally, a gyroscopic sensor senses an angular orientation and/or changes in angular orientation and/or movement with respect to a fixed axis. For example, when the angular sensor 130 includes a resonating Coriolis sensor, the angle and/or angular turning rate is detected by a vibrating planar ring mounted on a flexible frame. The resonating Coriolis sensor vibrates in a particular direction according to Coriolis forces, and any deviations from the particular direction can be detected to measure the angle and/or angular turning rate. In another example, the angular sensor 130 includes an optical gyroscopic sensor, which senses the angle and/or angular turning rate of an object based on the interference of light which has passed through a very long coil of optical fibre. Similarly, in additional embodiments, the angular sensor 130 may be a ring-laser gyroscope, or a differential accelerometer operable to measure the angle and/or angular turning rate.

The spin-control system 102 is operable to apply a retarding force and/or a reverse rotation to one or more of the rear wheels 112 of the electrical vehicle 100 when the angle and/or angular turning rate signal, namely the angle Θ, exceeds a threshold value.

The retarding force or reverse rotation is applied to the rear wheels 112 of the electrical vehicle 100 by the interaction of the spin control system 102 with the power control arrangement 108. The power control arrangement 108, which controls the electric power flow between the battery arrangement 106 and the electrical motor arrangement 110, drives the electrical motor arrangement 110 in a reverse direction. Furthermore, the electrical motor arrangement 110, when driven in a reverse direction has the effect of retarding the forward rotation of one or more rear wheels 112. Additionally, the electrical motor arrangement 110 driven in a reverse direction also has the effect of rotating one or more rear wheels 112 in a reverse direction momentarily.

The spin-control system 102 is operable to apply iteratively the retarding force and/or reverse rotation to one or more of the rear wheels 112 of the electrical vehicle 100 when the angle and/or angular turning rate signal exceeds the threshold value, as a function of a change in turning rate associated with each iteration. In an embodiment, the application of a momentary retarding force and/or reverse rotation to one or more rear wheels 112 by the electrical motor arrangement 110 has the effect of counter-acting the spin of the electrical vehicle 100. In a scenario where the electrical vehicle 100 is in a state of spin, the spin-control system 102 operates to apply a retarding force and/or reverse rotation to one or more rear wheels 112. Furthermore, if the angular sensor 130 detects a reduction in the angle and/or angular turning rate of the electrical vehicle 100, the spin-control system 102 continues to operate iteratively in a temporal manner of retarding force and/or reverse rotation of the rear wheels 112. The temporal manner of retarding force and/or reverse rotation by the spin-control system 102 is dependent upon the change in the angle and/or angular turning rate associated with each preceding iteration. Therefore, the spin-control system 102 continues to operate until the spin of the vehicle 100 is controlled and recovered from. For example, the spin-control system 100 may continue to operate until the angle and/or angular turning rate signal from the angular sensor 130 falls below the threshold value. Optionally, the threshold value is varied dynamically as the vehicle recovers from a given spin.

In an embodiment, the threshold value is a calculated (or predetermined) value of the magnitude of an angle and/or angular turning rate, exceeding which, the electrical vehicle 100 is approaching a state of excessive spin. In one embodiment, the threshold value of the angle and/or angular turning rate is varied depending upon a velocity of travel of the electrical vehicle 100. For example, while making a turn, the electrical vehicle 100 may have an optimal angular turning rate in order to change the angular orientation of the electrical vehicle 100 in accordance to a radius of the turn. Furthermore, the angular turning rate may be greater when the vehicle 100 is moving at a higher velocity, and lesser when the vehicle 100 is moving at a lower velocity. In such an embodiment, a threshold value of the angle and/or angular turning rate may be calculated based on the optimal turning rate at a particular velocity of movement. In another embodiment, calculation of threshold value of the angle and/or angular turning rate may also consider the intended steering angle of the vehicle 100.

Optionally, the spin-control system 102 may further comprise an indicator for providing indication of the angle and/or angular turning rate exceeding the threshold value. In an embodiment, an indicator may be installed at the vehicle console so as to be easily visible to the driver. Furthermore, the aforementioned indicator may comprise an indicating light, and a sound alert audible to the driver. Additionally, the indicator may be configured to indicate whenever the angle and/or angular turning rate exceed the threshold value. Such an indication is necessary as a safety-critical feature to alert the driver of the spin situation. Optionally, the indication is provided to the driver as an audio warning signal, so as not to distract the driver visually when making a complex manoeuver.

The spin-control system 102 may comprise additional sensing equipment to aid the angular sensor 130 to determine the state of spin of the electrical vehicle 100. The system comprise at least one torque sensor operatively coupled to at least one the rear wheels 112 for determining torque associated therewith for detecting loss of traction thereof. Typically, the rear wheels 112 may be associated with a pre-determined value of torque, exceeding which may cause loss of traction for the rear wheels 112. Furthermore, the torque sensors are communicably linked with the power control arrangement 108. The torque sensors determine the torque transmitted to the rear wheels 112 as well as their individual rotational speeds. Using the data provided by the torque sensors, the spin-control system may more efficiently detect spinning of the vehicle 100 due to loss of traction at the rear wheels 112. Therefore, the action of the spin-control system 102 to apply a retarding force/and or reverse rotation to one or more rear wheels 112 may be correlated with the detection of loss of traction.

In one embodiment, the spin-control system also includes a data processor (not shown). The data processor receives the angle and/or angular turning rate of the vehicle 100 from the angular sensor 130. Additionally, the data processor compares the received angle and/or angular turning rate of the vehicle 100 to a calculated threshold value. Furthermore, the data processor is communicably linked to the power control arrangement 108. In such an embodiment, the data processor is operable to communicate the angle and/or angular turning rate signal to the power control arrangement 108 to apply a retarding force and/or reverse rotation to the rear wheels 112. Moreover, the data processor is operable to receive data provided by the torque sensors to enable the spin-control system to detect loss of traction at the rear wheels 112.

According to an embodiment, in use, the spin-control system 102 measures an angular orientation of the vehicle 100 in terms of an angle and/or angular turning rate. Furthermore, the spin-control system 102 compares the measured angular orientation of the vehicle 100 with a threshold value of angle and/or angular turning rate. The threshold value may be dependent upon the speed of the vehicle 100. If the aforementioned threshold value is exceeded, the spin-control system 102 communicates an angle and/or angular turning rate signal to the power control arrangement 108 indicating that the vehicle 100 is approaching a condition of excessive spin. In order to counter-act and prevent the aforesaid spin condition, the power control arrangement 108 operates to drive the electrical motor arrangement 110 in a reverse direction. The electrical motor arrangement 108 being driven in reverse has the effect of providing a retarding force and/or reverse rotation to the rear wheels 112 of the electrical vehicle 100. The aforesaid retarding force and/or reverse rotation of the rear wheels 112 may be applied in an iterative manner depending upon measured change in angle and/or angular turning rate of the vehicle 100 during the preceding iterations. Furthermore, the spin-control system 102 in conjunction with the power control arrangement 108 and the electrical motor arrangement 110 continues to operate till the spin of the vehicle 100 is controlled and/or recovered. For example, the spin-control system 100 may continue to operate till the angle and/or angular turning rate signal from the angular sensor 130 falls below the threshold value.

Referring to FIG. 2, illustrated are steps for a method 200 of performing spin-control for an electrical vehicle, in accordance with an embodiment of the present disclosure. The method 200 of spin-control may be performed on the electrical vehicle, such as electrical vehicle 100, as shown in FIG. 1. Accordingly, the electrical vehicle includes a vehicle frame, a battery arrangement for storing energy, a power control arrangement for controlling an electrical power flow between the battery arrangement and an electrical motor arrangement. The electrical motor arrangement is operable to drive one or more rear wheels of the electrical vehicle.

At a step 202, an angular sensor is used for sensing and angular orientation of the electrical vehicle to provide an angle and/or angular turning rate signal. At a step 204, there is applied a retarding force and/or reverse rotation to one or more of the rear wheels of the electrical vehicle when the angle and/or angular turning rate signal exceeds a threshold value.

The steps 202 to 204 are only illustrative and other alternatives can also be provided where one or more steps are added, one or more steps are removed, or one or more steps are provided in a different sequence without departing from the scope of the claims herein. For example, the method 200 may comprise indicating exceeding of the threshold value using an indicator. In another example, the retarding force and/or reverse rotation may be applied iteratively to one or more of the rear wheels of the electrical vehicle when the angle and/or angular turning rate signal exceeds the threshold value, as a function of a change in turning rate associated with each iteration.

The spin-control system and the method of performing spin-control for electrical vehicles as described in the present disclosure is a safety-critical feature aimed at improving road safety on wet and/or slippery road conditions, and enhancing steering performance. Beneficially, the system and method disclosed efficiently prevent loss of traction on slick surfaces, such as wet or muddy roads, black ice or loose gravel. Furthermore, the system and method disclosed are relatively simple to implement and do not depend on driver intervention to control and recover from a spin. Therefore, the disclosed spin-control system and method for spin-control provide several advantages and enhances the traction control of electrical vehicles in inclement weather conditions, unfavorable surface conditions and high speeds.

Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as "including", "comprising", "incorporating", "have", "is" used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.

Claims

1. A spin-control system (102) for an electrical vehicle (100), wherein the electrical vehicle (100) comprises a vehicle frame (104), a battery arrangement (106) for storing energy, a power control arrangement (108) for controlling an electrical power flow between the battery arrangement (106), and an electrical motor arrangement (110) , wherein the electrical motor arrangement (110) is operable to drive one or more rear wheels (112) of the electrical vehicle; characterized in that: (i) the spin-control system (102) comprises an angular sensor (130) for sensing an angular orientation of the electrical vehicle (100) about a vertical axis through a center of gravity of the electrical vehicle (100) relative to an intended direction of the electrical vehicle, to provide an angle and/or angular turning rate signal (ii) the spin-control system (102) comprises of at least one torque sensor which is operatively coupled to at least one of the rear wheels (112) for determining torque associated with the at least one of the rear wheels (112) for detecting loss of traction thereof; (111) the spin-control system (102) is operable to apply a retarding force or a reverse rotation to one or more of the rear wheels (112110) of the electrical vehicle (100) when the angle and/or angular turning rate signal exceeds a threshold value wherein the threshold value is varied dynamically as the vehicle recovers from a given spin; and (iv) the spin control system (102) operates iteratively to drive a rear wheel in reverse or to apply a rotation retarding force to the rear wheel, such operation being in respect of one or more of the rear wheels (112) and being dependent upon the change in the angle and/or in the angular turning rate associated with the preceding iterative operation.

2. A spin-control system (102) of claim 1, characterized in that the threshold value of the angle and/or angular turning rate is varied depending upon a velocity of travel of the electrical vehicle (100).

3. A spin-control system (102) of any of the preceding claims, characterized in that the electrical motor arrangement (110) includes one or more hub motors mounted into rear wheels (112) of the electrical vehicle (100).

4. A spin-control system (102) of any of the preceding claims, characterized in that the system further comprises an indicator for providing indication of the angle and/or angular turning rate exceeding the threshold value.

5. A method (200) of performing spin-control for an electrical vehicle (100), wherein the electrical vehicle (100) includes a vehicle frame (104), a battery arrangement (106) for storing energy, a power control arrangement (108) for controlling an electrical power flow between the battery arrangement (106) and an electrical motor arrangement (110), wherein the electrical motor arrangement (110) is operable to drive one or more rear wheels (112) of the electrical vehicle (100), characterized in that the method (200) comprises: (i) using an angular sensor (130) for sensing an angular orientation of the electrical vehicle (100) about a vertical axis through a center of gravity of the electrical vehicle (100) relative to an intended direction of the electrical vehicle, to provide an angle and/or angular turning rate signal; (ii) using at least one torque sensor which is operatively coupled to at least one of the rear wheels (112) for determining torque associated with the at least one of the rear wheels (112) for detecting loss of traction thereof; (iii) applying a retarding force or reverse rotation to one or more of the rear wheels (112) of the electrical vehicle (100) when the angle and/or angular turning rate signal exceeds an threshold value wherein the threshold value is varied dynamically as the vehicle recovers from a given spin; and (iv) operating the spin control system (102) iteratively to drive a rear wheel in reverse or to apply a rotation retarding force to the rear wheel, such operation being in respect of one or more of the rear wheels (112) and being dependent upon the change in the angle and/or in the angular turning rate associated with the preceding iterative operation.

6. A method (200) of claim 5, characterized in that the method (200) further comprises indicating exceeding of the threshold value using an indicator.