SYSTEMS AND METHODS FOR MANAGING VEHICLE FOLLOWING DISTANCE USING ENGINE BRAKING

Abstract

Disclosed herein are systems and methods, implementable in a 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 degree of engine braking. Such engine braking 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 based on data received into the subject vehicle's electronic control unit through sensors for detecting surface slope and sensors for detecting vehicle pitch, which may be located on the subject vehicle.

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) a diesel engine; (b) an electronic control unit; (c) a first set of sensors located throughout the subject vehicle, which are communicatively and operatively connected to the electronic 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 located throughout the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting slope of a surface on which the subject vehicle is travelling; (e) a third set of sensors located throughout the engine of the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting degree of engine exhaust valve opening in the subject vehicle; and, (f) an engine brake; 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 electronic control unit communicating data concerning the change in slope of the surface; wherein the electronic control unit, based on the data concerning change in slope received from the second set of sensors, calculates a new desired degree of engine braking necessary to maintain substantially constant following distance relative to a target vehicle; and wherein the electronic control unit outputs to the engine brake a command signal to adjust engine exhaust valve position to one that corresponds to the new desired degree of engine braking.

2. The system of claim 1, wherein the engine brake comprises a compression brake.

3. The system of claim 1, wherein the engine brake comprises an exhaust brake.

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

5. The system of claim 4, wherein the second set of sensors are located on the transmission of the subject vehicle.

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) a diesel engine; (b) an electronic control unit; (c) a first set of sensors located throughout the subject vehicle, which are communicatively and operatively connected to the electronic 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 located throughout the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting pitch of the subject vehicle; (e) a third set of sensors located throughout the engine of the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting degree of engine exhaust valve opening in the subject vehicle; and (f) an engine brake; wherein, when the pitch of the subject vehicle changes, the second set of sensors transmit a signal to the electronic control unit communicating the change in vehicle pitch; wherein the electronic control unit, based on the data concerning change in vehicle pitch received from the second set of sensors, calculates a new desired degree of engine braking necessary to maintain substantially constant following distance relative to the target vehicle; and wherein the electronic control unit outputs to the engine brake a command signal to adjust engine exhaust valve position to one that corresponds to the new desired degree of engine braking.

7. The system of claim 6, wherein the engine brake comprises a compression brake.

8. The system of claim 6, wherein the engine brake comprises an exhaust brake.

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

10. The system of claim 9, wherein the second set of sensors are located on the transmission of the subject vehicle.

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 a diesel engine; (b) providing an electronic control unit; (c) providing a first set of sensors located throughout the subject vehicle, which are communicatively and operatively connected to the electronic 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 located throughout the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting slope of the surface on which the subject vehicle is travelling; (e) providing a third set of sensors located throughout the engine of the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting degree of engine exhaust valve opening in the subject vehicle; (f) providing an engine brake; and (g) 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 electronic control unit communicating data concerning the change in slope of the surface; wherein the electronic control unit, based on the data concerning change in slope received from the second set of sensors, calculates a new desired degree of engine braking necessary to maintain substantially constant following distance relative to a target vehicle; and wherein the electronic control unit outputs to the engine brake a command signal to adjust engine exhaust valve position to one that corresponds to the new desired degree of engine braking.

12. The method of claim 11, wherein the engine brake comprises a compression brake.

13. The method of claim 11, wherein the engine brake comprises an exhaust brake.

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

15. The method of claim 14, wherein the second set of sensors are located on the transmission of the subject vehicle.

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 a diesel engine; (b) providing an electronic control unit; (c) providing a first set of sensors located throughout the subject vehicle, which are communicatively and operatively connected to the electronic 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 located throughout the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting pitch of the subject vehicle; (e) providing a third set of sensors located throughout the engine of the subject vehicle, which are communicatively and operatively connected to the electronic control unit, wherein said sensors are capable of detecting degree of engine exhaust valve opening in the subject vehicle; (f) providing an engine brake; and (g) 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 electronic control unit communicating the change in vehicle pitch; wherein the electronic control unit, based on the data concerning change in vehicle pitch received from the second set of sensors, calculates a new desired degree of engine braking necessary to maintain substantially constant following distance relative to the target vehicle; and wherein the electronic control unit outputs to the engine brake a command signal to adjust engine exhaust valve position to one that corresponds to the new desired degree of engine braking.

17. The method of claim 16, wherein the engine brake comprises a compression brake.

18. The method of claim 16, wherein the engine brake comprises an exhaust brake.

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

20. The method of claim 19, wherein the second set of sensors are located on the transmission of the subject vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 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.

[0016] 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.

[0017] 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.

[0018] FIG. 4 is a flow chart depicting steps of methods according to the present disclosure.

DETAILED DESCRIPTION

[0019] The following disclosure concerns systems and methods, implementable in vehicles equipped with ACC, where the ACC feature is activated, for managing vehicle following distance by managing degree of engine braking 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] Various objects, features, aspects, and advantages described by this disclosure will become more apparent from the following detailed description, along with the accompanying drawings.

[0024] 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 a vehicle containing a diesel engine, 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. 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 engine braking, as it is used throughout this disclosure, shall mean a process involving decreasing the speed at which a subject vehicle's engine is operating through methods other than wheel braking. The term engine braking, as it is used throughout this disclosure, should be understood as encompassing both compression brakes (also referred to by those skilled in the art as compression release brakes or Jake brakes) and exhaust brakes. Consistent with the foregoing, the term engine brake(s), as it is used throughout this disclosure, should be understood as encompassing both compression brakes as well as exhaust brakes.

[0025] 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 degree of engine braking 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.

[0026] 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 subject vehicle equipped with an engine brake and a conventional ACC system that is activated is travelling on a downward sloping surface, the ACC system may increase the desired degree of engine braking 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 increased desired engine braking may be communicated to the ECU.

[0027] Conventional ACC systems, when there is a change in slope of the surface on which the subject vehicle is travelling, request a new desired degree of engine braking that is calibrated to a downward slope. This new requested engine braking 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 ECU and transmit data to the ECU 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 degree of engine braking may be identified by the ECU when there is a change in slope of the driving surface.

[0028] 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 degree of engine braking 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 degree of engine braking may be identified by the ECU when there is a change in pitch than with conventional ACC systems.

[0029] 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.

[0030] Components of systems of the present disclosure may include, without limitation, an ECU.

[0031] 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 ECU. 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.

[0032] 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 ECU. 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 transmission and/or within approximately six inches from such vehicle's wheel well. In instances where systems and methods of the present disclosure are deployed in a truck weighing more than approximately 10,000 pounds (referred to at times by those skilled in the art as a heavy truck), slope-detecting sensors as discussed herein may be located on the vehicle's transmission and/or elsewhere on such vehicle's powertrain. 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.

[0033] Components of systems of the present disclosure may include, without limitation, sensors that are capable of detecting degree of exhaust valve opening in the engine of a subject vehicle. Such sensors may be communicatively and operatively connected to the ECU. Those of skill in the art will readily appreciate suitable locations for placement of such sensors.

[0034] Components of systems of the present disclosure may include, without limitation, engine brakes. Those of skill in the art will readily appreciate suitable locations for placement of such engine brakes.

[0035] Systems of the present disclosure, as well as related methods of the present disclosure, are intended to operate in vehicles containing a diesel engine, equipped with an engine brake, and equipped with ACC, when such ACC has been activated.

[0036] 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 ECU communicating data regarding the change in slope of the surface. Based on the data concerning change in road slope received from such sensors, the ECU may calculate a new desired degree of engine braking necessary to maintain substantially constant following distance relative to a target vehicle.

[0037] Upon receipt by the ECU of data indicating a change in road slope, the ECU may calculate a new desired degree of engine braking and may output a command signal to the subject vehicle's engine brake to modify positioning of engine exhaust valves to allow for the desired degree of engine braking. Without limitation, such command signals from the ECU to the engine brake in a subject vehicle may correlate to low, medium, or high degrees of engine braking.

[0038] Such modifications in engine exhaust valve position may be effectuated in order to achieve a new desired degree of engine braking. Such new desired degree of engine braking 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.

[0039] 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.

[0040] According to such embodiment, when pitch of the subject vehicle changes, sensors located on the subject vehicle transmit a signal to the ECU 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 transmission and/or within approximately six inches from such vehicle's wheel well. In instances where systems and methods of the present disclosure are deployed in a heavy truck, pitch-detecting sensors as discussed herein may be located on the vehicle's transmission and/or elsewhere on such vehicle's powertrain. Those of skill in the art will readily appreciate alternative suitable locations for placement of such sensors.

[0041] Based on the data concerning change in vehicle pitch, the ECU may calculate a new desired degree of engine braking necessary to maintain substantially constant following distance relative to a target vehicle.

[0042] Upon receipt by the ECU of such vehicle pitch data, the ECU may calculate a new desired degree of engine braking and may output a command signal to the subject vehicle's engine brake to modify positioning of engine exhaust valves to allow for the desired degree of engine braking. Without limitation, such command signals from the ECU to the engine brake in a subject vehicle may correlate to low, medium, or high degrees of engine braking.

[0043] Such modifications in engine exhaust valve position may be effectuated in order to realize a new desired degree of engine braking. Such new degree of engine braking may be necessary in order to maintain a substantially constant following distance relative to a target vehicle where there has been a change pitch of the subject vehicle.

[0044] 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.