SYSTEMS AND METHODS FOR MANAGING ELECTRIC VEHICLE FOLLOWING DISTANCE

Abstract

Disclosed herein are systems and methods, implementable in an electric vehicle equipped with adaptive cruise control, for maintaining in a subject vehicle substantially constant following distance relative to a preceding target vehicle where there has been a change in slope of a surface on which the subject vehicle is travelling and/or where pitch of the subject vehicle has changed. Systems and methods disclosed herein may maintain such substantially constant following distance by managing torque in the vehicle's electric motor. Such engine torque management effective for maintaining substantially constant following distance relative to a preceding target vehicle, notwithstanding change in driving surface slope and/or change in pitch of the subject vehicle, may be realized utilizing data received into the subject vehicle's vehicle control unit through sensors for detecting surface slope and sensors for detecting vehicle pitch, which may be located on the subject vehicle's frame.

Claims

1. A system, implementable in a subject vehicle equipped with adaptive cruise control technology, for maintaining a substantially constant following distance from a target vehicle comprising: (a) an electric motor comprising a rotor and a stator; (b) a vehicle control unit; (c) a first set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting following distance relative to the target vehicle and the speed of the target vehicle; (d) a second set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting slope of a surface on which the subject vehicle is travelling; wherein, when the subject vehicle encounters a change in slope of a surface on which it is travelling, the second set of sensors transmits a signal to the vehicle control unit communicating data concerning the change in slope of the surface; wherein the vehicle control unit, based on the data concerning change in slope received from the second set of sensors, calculates a new desired torque value necessary to maintain substantially constant following distance relative to a target vehicle; and wherein the vehicle control unit adjusts torque to match the new desired torque value.

2. The system of claim 1, wherein the second set of sensors are located on the frame of the subject vehicle.

3. The system of claim 1, wherein the electric motor is a DC electric motor.

4. The system of claim 1, wherein the electric motor is an AC electric motor and wherein the subject vehicle further comprises an inverter.

5. The system of claim 4 wherein the vehicle control unit adjusts torque by sending a command signal to the inverter requesting that torque be set to match the new desired torque value.

6. A system, implementable in a subject vehicle equipped with adaptive cruise control technology, for maintaining a substantially constant following distance from a target vehicle comprising: (a) an electric motor, wherein the electric motor comprises a rotor and a stator; (b) a vehicle control unit; (c) a first set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting following distance relative to the target vehicle and the speed of the target vehicle; (d) a second set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting pitch of the subject vehicle; wherein, when the pitch of the subject vehicle changes, the second set of sensors transmit a signal to the vehicle control unit communicating the change in vehicle pitch; wherein the vehicle control unit, based on the data concerning change in vehicle pitch received from the second set of sensors, calculates a new desired torque value necessary to maintain substantially constant following distance relative to the target vehicle; and wherein the vehicle control unit adjusts torque to match the new desired torque value.

7. The system of claim 6, wherein the second set of sensors are located on the frame of the subject vehicle.

8. The system of claim 6, wherein the electric motor is DC electric motor.

9. The system of claim 6, wherein the electric motor is an AC electric motor and wherein the subject vehicle further comprises an inverter.

10. The system of claim 9 wherein the vehicle control unit adjusts torque by sending a command signal to the inverter requesting that torque be set to match the new desired torque value.

11. A method, implementable in a subject vehicle equipped with adaptive cruise control technology, for maintaining a substantially constant following distance relative to a preceding target vehicle comprising: (a) providing an electric motor, wherein the electric motor comprises a rotor and a stator; (b) providing a vehicle control unit; (c) providing a first set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting following distance relative to the target vehicle and the speed of the target vehicle; (d) providing a second set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting slope of the surface on which the subject vehicle is travelling; and (e) activating adaptive cruise control in the subject vehicle; wherein, when the subject vehicle encounters a change in slope of the surface on which it is travelling, the second set of sensors transmits a signal to the vehicle control unit communicating data concerning the change in slope of the surface; wherein the vehicle control unit, based on the data concerning change in slope received from the second set of sensors, calculates a new desired torque value necessary to maintain substantially constant following distance relative to a target vehicle; and wherein the vehicle control unit adjusts torque to match the new desired torque value.

12. The method of claim 11, wherein the second set of sensors are located on the frame of the subject vehicle.

13. The method of claim 11, wherein the electric motor is a DC electric motor.

14. The method of claim 11, wherein the electric motor is an AC electric motor and wherein the subject vehicle further comprises an inverter.

15. The method of claim 14 wherein the vehicle control unit adjusts torque by sending a command signal to the inverter requesting that torque be set to match the new desired torque value.

16. A method, implementable in a subject vehicle equipped with adaptive cruise control technology, for maintaining a substantially constant following distance relative to a preceding target vehicle comprising: (a) providing an electric motor, wherein the electric motor comprises a rotor and a stator; (b) providing a vehicle control unit; (c) providing a first set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting following distance relative to the target vehicle and the speed of the target vehicle; (d) providing a second set of sensors communicatively and operatively connected to the vehicle control unit, wherein said sensors are capable of detecting pitch of the subject vehicle; and (e) activating adaptive cruise control in the subject vehicle; wherein, when the pitch of the subject vehicle changes, the second set of sensors transmit a signal to the vehicle control unit communicating the change in vehicle pitch; wherein the vehicle control unit, based on the data concerning change in vehicle pitch received from the second set of sensors, calculates a new desired torque value necessary to maintain substantially constant following distance relative to the target vehicle; and wherein the vehicle control unit adjusts torque to match the new desired torque value.

17. The method of claim 16, wherein the second set of sensors are located on the frame of the subject vehicle.

18. The method of claim 16, wherein the electric motor is a DC electric motor.

19. The method of claim 16, wherein the electric motor is an AC electric motor and wherein the subject vehicle further comprises an inverter.

20. The method of claim 19 wherein the vehicle control unit adjusts torque by sending a command signal to the inverter requesting that torque be set to match the new desired torque value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 depicts a left side view of a vehicle that is travelling on a substantially flat surface and is equipped with sensors for determining slope of the surface, as contemplated by systems and methods of the present invention.

[0022] FIG. 2 depicts a left side view of a vehicle that is travelling on an upward sloping surface and is equipped with sensors for determining slope of the surface, as contemplated by systems and methods of the present invention.

[0023] FIG. 3 depicts a left side view of a vehicle that is travelling on a downward sloping surface and is equipped with sensors for determining slope of the surface, as contemplated by systems and methods of the present invention.

[0024] FIG. 4 is a flow chart depicting steps of methods according to the present disclosure.

DETAILED DESCRIPTION

[0025] The following disclosure concerns systems and methods, implementable in electric vehicles equipped with ACC, where the ACC feature is activated, for managing vehicle following distance by managing torque and torque reduction in a subject vehicle. Skilled artisans will appreciate additional embodiments of systems and methods of the present disclosure that extend beyond the examples of this disclosure.

[0026] When reading this disclosure, singular forms should be read to contemplate and disclose plural alternatives. Similarly plural forms should be read to contemplate and disclose singular alternatives. Conjunctions should be read as inclusive unless stated otherwise.

[0027] Expressions such as at least one of A, B, and C should be read to permit any one of A, B, or C, alone or in combination with the remaining elements. Additionally, such groups may include multiple instances of one or more elements in that group, which may be included with other elements of that group. All numbers, measurements, and values are given as approximations unless expressly stated otherwise.

[0028] Terms and expressions used throughout this disclosure are to be interpreted broadly. Terms are intended to be understood respective to the definitions provided by this specification. Technical dictionaries and common meanings understood within the applicable art are intended to supplement these definitions. In instances where no suitable definition can be determined from the specification or from technical dictionaries, such terms should be understood according to their plain and common meaning. However, any definitions provided by the specification will govern above all other sources.

[0029] Various objects, features, aspects, and advantages described by this disclosure will become more apparent from the following detailed description, along with the accompanying drawings.

[0030] For purposes of clearly describing the components, features, and method steps discussed throughout this disclosure, some frequently used terms will now be defined. The term subject vehicle, as it is used throughout this disclosure, shall mean an electric vehicle, equipped with ACC and operating with ACC activated, comprising a system of the present disclosure and/or operating according to a method of the present disclosure. Such subject vehicles should be understood to include substantially all components that modern electric vehicles possess. Those skilled in the art will readily appreciate the identify of such components. Such components may include, without limitation, a battery pack, a battery management system, an electric motor, an inverter (where the motor is an AC motor), and a charging port. The term target vehicle, as it is used throughout this disclosure, shall mean a vehicle located some distance in front of a subject vehicle and with respect to which speed of the subject vehicle is calibrated so as to maintain substantially constant following distance. The term electric motor, as it is used throughout this disclosure, is intended to include both alternating current (AC) and direct current (DC) electric vehicle motors, unless otherwise indicated. The term electric motor should be understood to include all components typically found in modern electric vehicle AC or DC motors, as applicable. Those skilled in the art will readily appreciate the identify of such components. Such components may include, among others, a rotor, a shaft, and a stator.

[0031] Various aspects of the disclosure will now be described in detail, without limitation. In the following disclosure, systems and methods for controlling vehicle following distance by managing torque and torque reduction in a subject vehicle, will be discussed. Those of skill in the art will appreciate that alternative labeling of the components, features, and method steps may be provided, which is consistent with the scope and spirit of this disclosure. Skilled readers should not view inclusion of any alternative labels as limiting in any way.

[0032] ACC systems are commonly found in many different makes and models of vehicles today. ACC systems in a subject vehicle may be utilized to maintain a substantially constant following distance behind a preceding target vehicle located in front of the subject vehicle. When a vehicle with a conventional ACC system activated is travelling on a downward sloping surface, the ACC system may decrease the desired torque value to off-set acceleration due to gravity caused by the downward slope of the surface. Such off-set may be necessary to maintain a substantially constant following distance relative to a target vehicle given the increase in speed due to the downward sloping surface. Such decreased desired torque may be communicated to the VCU. The VCU may then, in an electric vehicle comprising an AC motor, communicate the new desired torque to the inverter. The inverter may then effectuate the new desired torque by modifying the frequency and amplitude of the alternating current applied to the rotor. In an electric vehicle comprising a DC motor, the VCU may effectuate the new desired torque by modifying the voltage of the direct current being applied to the rotor.

[0033] Conventional ACC systems, when there is a change in slope of the surface on which the subject vehicle is travelling, request a new desired torque that is calibrated to a downward slope. This new requested torque is, therefore, not optimal for upward sloping and substantially flat surfaces. Systems and methods of the present disclosure solve this problem by utilizing sensors that are communicatively and operatively connected to the VCU and transmit data to the VCU regarding slope of the surface on which the subject vehicle is travelling. With this information regarding slope of the surface, a more appropriate new desired torque may be identified by the VCU when there is a change in slope of the driving surface.

[0034] In an alternative embodiment, systems and methods of the present disclosure comprise a series of sensors that detect pitch of a subject vehicle. When vehicle pitch changes, a new desired torque will be identified to off-set forces causing the change in pitch. With this information regarding pitch of the subject vehicle, a more appropriate new desired torque may be identified by the VCU when there is a change in pitch than with conventional ACC systems.

[0035] Systems and methods of the present disclosure may be utilized in a subject vehicle. Systems and methods of the present disclosure may be utilized to maintain a substantially constant following distance behind a target vehicle.

[0036] Components of systems of the present disclosure may include, without limitation, an electric motor. Such electric motor may be an AC motor or a DC motor. Where the electric motor is an AC motor, the electric motor may further comprise an inverter.

[0037] Components of systems of the present disclosure may include, without limitation, a VCU.

[0038] Components of systems of the present disclosure may include, without limitation, radar sensors capable of detecting following distance relative to a target vehicle and capable of detecting speed of the target vehicle. Such sensors may be communicatively and operatively connected to the VCU. Those of skill in the art will readily appreciate suitable locations throughout the subject vehicle for placement of such radar sensors. Without limitation, such radar sensors may be located behind the grill of a subject vehicle.

[0039] Components of systems of the present disclosure may include, without limitation, sensors that are capable of detecting slope of the surface on which the subject vehicle is travelling. Such sensors may be communicatively and operatively connected to the VCU. Such sensors may be located throughout the subject vehicle at any position that is substantially stable when the subject vehicle is being driven. Without limitation, such sensors may be located on a vehicle's frame within approximately six inches from such vehicle's wheel well. Those of skill in the art will readily appreciate alternative suitable locations for placement of the slope-detecting sensors and pitch-detecting sensors discussed herein.

[0040] Systems of the present disclosure, as well as related methods of the present disclosure, are intended to operate in electric vehicles equipped with ACC when such ACC has been activated.

[0041] According to systems and methods of the present disclosure, and referring to FIGS. 1-3, when a subject vehicle encounters a change in slope of the surface on which it is travelling, sensors transmit a signal to the VCU communicating data regarding the change in slope of the surface. Based on the data concerning change in road slope received from such sensors, the VCU may calculate a new desired torque value necessary to maintain substantially constant following distance relative to a target vehicle.

[0042] Upon receipt by the VCU of such road slope data, in vehicles containing an AC electric motor, the VCU, according to systems and methods of the present disclosure, may calculate a new desired torque value and may output this new desired torque value to the inverter. Modifications to the frequency and/or amplitude of the AC current emitted by the inverter may be effectuated in order to achieve the new desired torque value. Such new torque value may be necessary in order to maintain a substantially constant following distance relative to a target vehicle where there has been a change in slope of the surface on which the subject vehicle is travelling. Where the subject vehicle comprises a DC electric motor, the VCU may transmit a command signal adjusting the voltage of the direct current to the rotor in order to modify torque to maintain a substantially constant following distance relative to a target vehicle where there has been a change in slope of the surface on which the subject vehicle is travelling.

[0043] In an alternative embodiment, systems of the present disclosure may comprise sensors capable of detecting pitch of the subject vehicle in lieu of or in addition to sensors for detecting slope of a surface on which the subject vehicle is travelling.

[0044] According to such embodiment, when pitch of the subject vehicle changes, sensors located on the subject vehicle transmit a signal to the VCU communicating data concerning the change in vehicle pitch. Such sensors may be located at any position on the subject vehicle that preserves effectiveness of the sensors. Without limitation, such sensors may be positioned as reflected in FIGS. 1-3. According to aspects of systems enabled by this disclosure, pitch-detecting sensors as discussed herein may be positioned, without limitation, on a vehicle's frame within approximately six inches from such vehicle's wheel well. Those of skill in the art will readily appreciate alternative suitable locations for placement of such sensors.

[0045] Based on the data concerning change in vehicle pitch, the VCU may calculate a new desired torque value necessary to maintain substantially constant following distance relative to a target vehicle.

[0046] Upon receipt by the VCU of such vehicle pitch data, in vehicles containing an AC electric motor, the VCU, according to systems and methods of the present disclosure, may calculate a new desired torque value and may output this new desired torque value to the inverter. Modifications to the frequency and/or amplitude of the AC current emitted by the inverter may be effectuated in order to achieve the new desired torque value. Such new torque value may be necessary in order to maintain a substantially constant following distance relative to a target vehicle where there has been a change in vehicle pitch. Where the subject vehicle comprises a DC electric motor, the VCU may transmit a command signal adjusting the voltage of the direct current to the rotor in order to modify torque to maintain a substantially constant following distance relative to a target vehicle where there has been a change in vehicle pitch.

[0047] While various aspects of systems and methods enabled by this disclosure have been described above, the description of this disclosure is intended to illustrate and not limit the scope of the invention. The invention is defined by the scope of the claims and not the illustrations and examples provided in the above disclosure. Skilled artisans will appreciate additional aspects of the systems and methods enabled by this disclosure, which may be realized in alternative embodiments, after having the benefit of the above disclosure. Other aspects, advantages, embodiments, and modifications are within the scope of the claims.