Patent Application
20230202439
The present disclosure relates to braking systems and methods, and, more particularly, to systems and methods for braking vehicles and coupled trailers.
Vehicle-trailer assemblies include vehicles, such as tractors, used for moving commerce, also simply referred to as tractor trailers, and vehicles used in connection with the agricultural industry, such as a tractor coupled to a trailer via a trailer hitch, tow bar, or other coupling devices, to enable the tractor to tow the trailer. Typically, the vehicle has a braking system that produces braking pressure to activate brakes of the vehicle and may also be coupled to one or more brakes of the trailer to cause braking of the trailer as well. The delivery of braking pressure from the vehicle to the trailer brakes may be controlled by a trailer brake valve of the vehicle. While such assemblies are effective, there are certain situations when the braking pressure delivered to the trailer brake(s) from the trailer brake valve may be too high or too low.
What is needed in the art is a way to deliver braking pressure to one or more trailer brakes of a trailer in an improved manner.
Exemplary embodiments provided according to the present disclosure provide a vehicle with an electronic control unit that is configured to adjust a trailer brake valve to output variable trailer brake pressures, which are a function of a vehicle brake pressure, according to different vehicle brake pressure curves.
In some embodiments provided according to the present disclosure, a vehicle includes: a brake pedal configured to produce vehicle brake pressure; a vehicle brake configured to receive the vehicle brake pressure; a final drive coupled to the vehicle brake; a vehicle wheel coupled to the final drive; a trailer brake valve configured to output a variable trailer brake pressure to a trailer brake of a trailer coupled to the vehicle, the trailer brake valve being configured to output the variable trailer brake pressure as a function of the vehicle brake pressure; and an electronic control unit (ECU) operably coupled to the trailer brake valve and configured to: output a first valve signal to the trailer brake valve to cause the trailer brake valve to output the variable trailer brake pressure according to a first vehicle brake pressure curve; determine a curve adjustment condition exists; and output a second valve signal to the trailer brake valve to cause the trailer brake valve to output the variable trailer brake pressure according to a second vehicle brake pressure curve that differs from the first vehicle brake pressure curve responsively to determining the curve adjustment condition exists. At least one of the first vehicle brake pressure curve or the second vehicle brake pressure curve is not a single straight line curve.
In some embodiments provided according to the present disclosure, a vehicle system includes: a vehicle including: a brake pedal configured to produce vehicle brake pressure; a vehicle brake configured to receive the vehicle brake pressure; a final drive coupled to the vehicle brake; a vehicle wheel coupled to the final drive; and a trailer brake valve configured to output a variable trailer brake pressure, the trailer brake valve being configured to output the variable trailer brake pressure as a function of the vehicle brake pressure; a trailer coupled to the vehicle, the trailer including at least one trailer brake coupled to the trailer brake valve so as to receive the output variable trailer brake pressure from the trailer brake valve; and an electronic control unit (ECU) operably coupled to the trailer brake valve and configured to: output a first valve signal to the trailer brake valve to cause the trailer brake valve to output the variable trailer brake pressure according to a first vehicle brake pressure curve; determine a curve adjustment condition exists; and output a second valve signal to the trailer brake valve to cause the trailer brake valve to output the variable trailer brake pressure according to a second vehicle brake pressure curve that differs from the first vehicle brake pressure curve responsively to determining the curve adjustment condition exists. At least one of the first vehicle brake pressure curve or the second vehicle brake pressure curve is not a single straight line curve.
In some embodiments provided according to the present disclosure, a method of adjusting braking performance of a trailer coupled to a vehicle includes: producing vehicle brake pressure by the vehicle; outputting a first trailer brake pressure from a trailer brake valve of the vehicle to at least one trailer brake of the trailer, the output first trailer brake pressure is a function of the vehicle brake pressure that is output according to a first vehicle brake pressure curve; determining a curve adjustment condition exists; and adjusting the trailer brake valve so the trailer brake valve is configured to output a second trailer brake pressure to the at least one trailer brake, the second trailer brake pressure is a function of the vehicle brake pressure and is output according to a second vehicle brake pressure curve that differs from the first vehicle brake pressure curve. At least one of the first vehicle brake pressure curve or the second vehicle brake pressure curve is not a single straight line curve.
A possible advantage that may be realized by embodiments provided according to the present disclosure is that the first vehicle brake pressure curve and the second vehicle brake pressure curve can each be tailored to different conditions, such as differing loads of the trailer, so braking performance can be improved in the different conditions.
Another possible advantage that may be realized by embodiments provided according to the present disclosure is that the trailer brake valve can be conveniently controlled by the ECU to alter braking performance, allowing adjustment of the trailer brake valve without prolonged stoppage of the vehicle.
Yet another possible advantage that may be realized by embodiments provided according to the present disclosure is that the ECU can be configured to allow a user to define when one or more of the vehicle brake pressure curves is used, which may improve user comfort and satisfaction with the braking performance.
For the purpose of illustration, there are shown in the drawings certain embodiments of the present invention. It should be understood, however, that the invention is not limited to the precise arrangements, dimensions, and instruments shown. Like numerals indicate like elements throughout the drawings. In the drawings:
The terms “fore”, “aft”, “left” and “right”, when used in connection with a vehicle assembly and/or components thereof are usually determined with reference to the direction of forward operative travel of the vehicle assembly, but they should not be construed as limiting. The terms “longitudinal” and “transverse” are determined with reference to the fore-and-aft direction of the vehicle assembly and are equally not to be construed as limiting.
Referring now to the drawings, and more particularly to
The brake pedal 110, when depressed, actuates the master cylinder 206 to produce a vehicle brake pressure (e.g., a hydraulic vehicle brake pressure) in the brake line 212 for activating the vehicle brake 210. The vehicle brake 210 brakes the rear axle 237, and the final drive 214 couples the braking action on the rear axle 237 to a braking action on the vehicle wheel 216 (e.g., on the rear wheels 106B, 106D). Braking assemblies including final drives and wheels are well known and will not be described in further detail. It should be appreciated that while the brake pedal 110 appears in the form of a foot-operated pedal that is mounted to the floor of the vehicle 102, in some embodiments the brake pedal 110 is hand-operated, e.g., a joystick, and may be part of an assembly that controls both propulsion and braking of the vehicle 102. Thus, the brake pedal 110 provided according to the present disclosure may be any element that, when activated, produces vehicle brake pressure that may be used to brake the vehicle 102 and the trailer 104.
The vehicle braking section 202 also includes a trailer brake valve 218 coupled to the master cylinder 206 via a pilot brake line 213 for piloting the vehicle brake pressure to the trailer brake valve 218 and the ECU 107 may be configured to receive a brake signal from the brake pedal 110 of the vehicle 102 that is representative of the vehicle brake pressure applied to the vehicle brake 210 for braking the vehicle wheel 216. In some embodiments, the brake signal is an electrical signal generated by a transducer (not shown), such as an electromechanical sensor coupled between the mechanical linkage 208 of the brake pedal 110 and the ECU 107, as is known in the art.
The trailer braking section 204 includes at least one trailer brake 220 and a trailer wheel 224 (e.g., one of the trailer wheels 108 of
In some embodiments, upon activation of the vehicle brake 210, the vehicle brake pressure is piloted to the trailer brake valve 218 via the pilot brake line 213. The trailer brake valve 218 also receives the trailer brake valve control signal from the ECU 107 for controlling application of the piloted vehicle brake pressure to the trailer brake valve 218 for adjusting (or setting) the trailer brake pressure in the trailer brake line 222 to the defined pressure for activating the one or more trailer brakes 220. In some embodiments, the trailer braking section 204 includes a source of trailer brake pressure 228 (e.g., a trailer brake pump) configured to receive the trailer brake valve control signal from the ECU 107 for adjusting (or setting) the trailer brake pressure in the trailer brake line 222 to the defined pressure for activating the one or more trailer brakes 220. In some embodiments, the source of trailer brake pressure 228 can maintain a pressure in the trailer brake line 222.
In known braking assemblies, the trailer brake valve may be configured to output trailer brake pressure to the trailer brake(s) as a function of the vehicle brake pressure. For example, the trailer brake valve may be configured to output trailer brake pressure in a 1.5:1 relationship with the vehicle brake pressure so the trailer brake pressure output to the trailer brake(s) is equal to two-thirds the vehicle brake pressure supplied to the vehicle brake(s). While such assemblies are effective to stop the vehicle and trailer, there have been issues identified with such an arrangement.
One particular issue that has been found is that the set function for the trailer brake pressure from the vehicle brake pressure may not always be ideal for the operating conditions. For example, if the trailer is heavily loaded, the trailer brake pressure output by the trailer brake valve may not be as high as the user desires even if the set function was acceptable when the trailer was less loaded. The user may thus believe that the braking performance is not “aggressive” enough when the trailer is loaded. On the other hand, if the trailer brake valve were configured to have a set function that were more aggressive, i.e., the trailer brake pressure was closer to equal to or even greater than the vehicle brake pressure, the user may believe that the braking performance is too aggressive when the trailer is less loaded or even empty.
To address some of the previously described issues, and referring now to
In some embodiments, the ECU 107 is configured to determine the curve adjustment condition exists based on a weight of the trailer 104. For example, the ECU 107 may be configured to receive a trailer weight signal corresponding to a trailer weight of the coupler trailer 104 and determine the curve adjustment condition exists based at least partially on the trailer weight being greater than a defined weight. The ECU 107 may initially output the first valve signal to the trailer brake valve 218 so the trailer brake valve 218 is configured to output the trailer brake pressure according to the first vehicle brake pressure curve 301 when the trailer 104 is not heavily loaded, which is when the user may desire less aggressive braking of the trailer 104. When the trailer 104 becomes more heavily loaded, such as loaded to the point where the trailer 104 exceeds the defined weight, the ECU 107 may receive the trailer weight signal, determine the trailer weight exceeds the defined weight, and output the second valve signal to the trailer brake valve 218 so the trailer brake valve 218 is configured to output the trailer brake pressure according to the second vehicle brake pressure curve 302, which has a steeper curve portion 302B than a corresponding curve portion 301A of the first vehicle brake pressure curve 301 and thus provides more aggressive braking. Since the trailer 104 is generally more difficult to brake when more heavily loaded due to inertia, the more aggressive braking performance of the second vehicle brake pressure curve 302 can allow the user to brake the vehicle 102 and the trailer 104 more quickly than if the trailer brake valve 218 was outputting trailer brake pressure according to the first vehicle brake pressure curve 301.
The ECU 107 may determine the weight of the trailer 104 in a variety of ways. In some embodiments, the trailer 104 includes one or more trailer weight sensors 201 that are configured to output the trailer weight signal. The ECU 107 may be operably coupled to the trailer weight sensor(s) 201 and determine the curve adjustment condition exists based on the trailer weight signal received from the trailer weight sensor(s) 201.
In some embodiments, and referring now to
In some embodiments, the ECU 107 is configured to determine a second curve adjustment condition exists and output a third valve signal to the trailer brake valve 218 to cause the trailer brake valve 218 to output the variable trailer brake pressure according to a third vehicle brake pressure curve 303 that differs from the first vehicle brake pressure curve 301 and the second vehicle brake pressure curve 302 responsively to determining the second curve adjustment condition exists. The ECU 107 may determine the second curve adjustment condition exists, for example, when a user selects the icon 413 in the GUI 410, prompting the display 400 to output a second curve adjustment signal to the ECU 107. As previously described, the icon 413 may be presented to the user as corresponding to a braking performance setting that is suited for use when the trailer 104 is heavily/fully loaded and/or the user desires even more aggressive braking performance. It should be appreciated that while the icons 411, 412, 413 are illustrated and described as presenting descriptions about the load level of the trailer 104, in some embodiments the icons 411, 412, 413 present descriptions about other driving characteristics and/or user preference, e.g., road conditions, desired braking performance, etc. The user may thus select one of the icons 411, 412, 413 to alter the vehicle brake pressure curve followed by the trailer brake valve 218 and adjust the braking performance of the system 100 in a convenient manner.
In some embodiments, the ECU 107 is configured to receive a defined weight adjustment signal and adjust the defined weight that is used to determine when a curve adjustment condition exists. Referring still to
The trailer 104 may be coupled to a draw bar 120 of the vehicle 102 and a draw bar load sensor 121 may be coupled to the draw bar 120 and operably coupled to the ECU 107. The draw bar load sensor 121 may be configured to output a draw bar load signal to the ECU 107 that corresponds to a draw bar load exerted on the draw bar 120. The ECU 107 may be configured to determine the curve adjustment condition exists when the draw bar load is greater than a defined draw bar load. The load experienced at the draw bar 120 may be due to a mismatch in deceleration of the vehicle 102 and the trailer 104; if the vehicle 102 and the trailer 104 decelerate at the same rate, there may be little load experienced by the draw bar 120. By having the ECU 107 configured to determine the curve adjustment condition exists when the draw bar load on the draw bar 120 exceeds the defined draw bar load, the ECU 107 can output a respective valve signal to the trailer brake valve 218 in order to adjust braking performance so the vehicle 102 and the trailer 104 decelerate more similarly. In such embodiments, a user may accelerate the vehicle 102 to a test speed and activate the brake pedal 110 to stop the vehicle 102 and the trailer 104. Based on the load experienced in the draw bar 120 as the vehicle 102 and the trailer 104 decelerate to a stop, the ECU 107 may determine if a valve signal should be output to the trailer brake valve 218 in order to adjust the braking performance. It should thus be appreciated that the ECU 107 may be configured to determine the curve adjustment condition exists in a variety of ways in addition, or alternatively, to determining the weight of the trailer 104.
From the foregoing, it should be appreciated that the system 100 provided according to the present disclosure has an ECU 107 that can output on or more valve signals to control the trailer brake valve 218 and adjust the braking performance of the trailer 104 in response to various conditions. Controlling the trailer brake valve 218 in this manner can allow a user to choose the aggressiveness of the braking and, in some embodiments, may be performed by the ECU 107 without user input so the system 100 operates according to manufacturer settings. The system 100 can thus improve user comfort and perception with the braking performance due to the trailer brake valve 218 being adjustable to different conditions.
In some embodiments provided according to the present disclosure, and referring now to
It is to be understood that some or all of the steps of the methods 500 may be performed by the ECU 107 upon loading and executing software code or instructions which are tangibly stored on a tangible computer readable medium, such as on a magnetic medium, e.g., a computer hard drive, an optical medium, e.g., an optical disc, solid-state memory, e.g., flash memory, or other storage media known in the art. Thus, any of the functionality performed by the ECU 107 described herein, such as some or all steps of the method 500, is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. The ECU 107 loads the software code or instructions via a direct interface with the computer readable medium or via a wired and/or wireless network. Upon loading and executing such software code or instructions by the ECU 107, the ECU 107 may perform any of the functionality of the ECU 107 described herein, including some or all steps of the method 500 described herein.
The term “software code” or “code” used herein refers to any instructions or set of instructions that influence the operation of a computer or controller. They may exist in a computer-executable form, such as machine code, which is the set of instructions and data directly executed by a computer’s central processing unit or by a controller, a human-understandable form, such as source code, which may be compiled in order to be executed by a computer’s central processing unit or by a controller, or an intermediate form, such as object code, which is produced by a compiler. As used herein, the term “software code” or “code” also includes any human-understandable computer instructions or set of instructions, e.g., a script, that may be executed on the fly with the aid of an interpreter executed by a computer’s central processing unit or by a controller.
These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it is to be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It is to be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention.
