APPARATUS AND METHOD FOR AN AUTOMATIC TRACTION SYSTEM

Abstract

An automatic traction system adapted for use on a paving machine having a steering cylinder, one or more wheels, and a joystick. The preferred automatic traction system has a joystick sensor adapted to determine a joystick position, a steering sensor adapted to determine a steering cylinder position, a speed sensor adapted to determine an actual speed of one or more of the one or more wheels, a valve adapted to be moved between an open position and a closed position and is in fluid communication with one or more of the one or more wheels, and a controller adapted to communicate with the joystick sensor, the steering sensor, the speed sensor, and the valve. The preferred automatic traction system automatically controls the rotational speed of the one or more wheels of the paving machine in the event that one or more of the one or more wheels lose traction.

Claims

1. An automatic traction system adapted for use on a paving machine having a steering cylinder, one or more wheels, and a joystick, said automatic traction system comprising: (a) a joystick sensor, said joystick sensor being adapted to determine a joystick position; (b) a steering sensor, said steering sensor being adapted to determine a steering cylinder position; (c) a speed sensor, said speed sensor being adapted to determine an actual speed of one or more of the one or more wheels; (d) a valve, said valve being adapted to be moved between an open position and a closed position and being in fluid communication with one or more of the one or more wheels; (e) a controller, said controller being adapted to communicate with the joystick sensor, the steering sensor, the speed sensor, and the valve; wherein the automatic traction system automatically controls the rotational speed of the one or more wheels of the paving machine in the event that one or more of the one or more wheels lose traction.

2. The automatic traction system of claim 1 wherein the controller is adapted to determine a target speed based on the joystick position and the steering cylinder position.

3. The automatic traction system of claim 2 wherein the controller is adapted to determine whether the actual speed is within a tolerance of the target speed.

4. The automatic traction system of claim 3 wherein the tolerance is approximately 25% of the target speed.

5. The automatic traction system of claim 3 wherein the tolerance is approximately 10% of the target speed.

6. The automatic traction system of claim 5 wherein the valve comprises a Front-Wheel-Assist valve.

7. The automatic traction system of claim 6 wherein the Front-Wheel-Assist valve has a paving machine speed threshold.

8. The automatic traction system of claim 7 wherein the valve comprises a Posi-Lock valve.

9. The automatic traction system of claim 8 wherein the Posi-Lock valve and the Front-Wheel-Assist valve are moved to the open position for a period of time in the event the actual speed is not within the tolerance of the target speed and the paving machine speed threshold is not exceeded.

10. The automatic traction system of claim 9 wherein the period of time is predetermined.

11. The automatic traction system of claim 9 wherein the period of time is approximately 2 seconds.

12. The automatic traction system of claim 9 wherein the period of time is approximately 1 second.

13. The automatic traction system of claim 9 wherein the Posi-Lock valve and the Front-Wheel-Assist valve move to the closed position after the period of time.

14. The automatic traction system of claim 1 wherein the paving machine has an automatic traction mode.

15. The automatic traction system of claim 1 wherein the valve may be manually moved between the open position and the closed position.

16. An automatic traction system adapted for use on a paving machine having a steering cylinder, one or more wheels, and a joystick, said automatic traction system comprising: (a) a joystick sensor, said joystick sensor being adapted to determine a joystick position; (b) a steering sensor, said steering sensor being adapted to determine a steering cylinder position; (c) a speed sensor, said speed sensor being adapted to determine an actual speed of one or more of the one or more wheels; (d) a Posi-Lock valve, said Posi-Lock valve being adapted to be moved between an open position and a closed position and being in fluid communication with one or more of the one or more wheels; (e) a Front-Wheel-Assist valve, said Front-Wheel-Assist valve being adapted to be moved between an open position and a closed position and being in fluid communication with one or more of the one or more wheels; (f) a controller, said controller being adapted to communicate with the joystick sensor, the steering sensor, the speed sensor, the Posi-Lock valve, and the Front-Wheel-Assist valve; wherein the automatic traction system automatically controls the rotational speed of the one or more wheels of the paving machine in the event that one or more of the one or more wheels lose traction.

17. A method for controlling the movement of a paving machine having a steering cylinder, one or more wheels, and a joystick, said method comprising: (a) providing an automatic traction system, said automatic traction system comprising: (i) a joystick sensor, said joystick sensor being adapted to determine a joystick position; (ii) a steering sensor, said steering sensor being adapted to determine a steering cylinder position; (iii) a speed sensor, said speed sensor being adapted to determine an actual speed of one or more of the one or more wheels; (iv) a valve, said valve being adapted to be moved between an open position and a closed position and being in fluid communication with one or more of the one or more wheels; (v) a controller, said controller being adapted to communicate with the joystick sensor, the steering sensor, the speed sensor, and the valve; wherein the automatic traction system automatically controls the rotational speed of the one or more wheels of the paving machine in the event that one or more of the one or more wheels lose traction; (b) moving the valve between the open position and the closed position.

18. The method of claim 17 further comprising: (c) determining a target speed.

19. The method of claim 18 further comprising: (d) comparing the actual speed with the target speed.

20. The method of claim 19 further comprising: (e) determining if the actual speed is within a tolerance of the target speed.

21. The method of claim 20 further comprising: comparing the actual speed with a paving machine speed threshold.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The presently preferred embodiments of the invention are illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout, and in which:

[0018] FIG. 1 is a perspective view of the cockpit of an exemplary paving machine illustrating the preferred embodiment of the joystick sensor in accordance with the present invention.

[0019] FIG. 2 is a bottom view of the exemplary paving machine illustrated in FIG. 1 showing the preferred embodiment of the steering sensor.

[0020] FIG. 3 is a perspective view of a wheel of the exemplary paving machine illustrated in FIGS. 1-2 showing the preferred embodiment of the speed sensor.

[0021] FIG. 4 is a perspective view of a front wheel well of the exemplary paving machine illustrated in FIGS. 1-3 showing the preferred embodiment of the valve.

[0022] FIG. 5 is a partial sectional top view of the engine compartment of the exemplary paving machine illustrated in FIGS. 1-4 showing the preferred embodiment of the controller.

[0023] FIG. 6 is a flow chart illustrating the preferred method for an automatic traction system.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

[0024] Referring now to the drawings, the preferred embodiment of the automatic traction system in accordance with the present invention is illustrated by FIGS. 1 through 6. Referring now to FIG. 1, a perspective view of the cockpit of an exemplary paving machine illustrating the preferred embodiment of the joystick sensor in accordance with the present invention is illustrated. As shown in FIG. 1, the exemplary paving machine is designated generally by reference numeral 20 and the preferred embodiment of the joystick sensor is designated generally by reference numeral 30. Exemplary paving machine 20 preferably has an automatic traction mode in which the automatic traction system operates without any user input or manual interaction. Preferred joystick sensor 30 is adapted to determine the position of preferred joystick 32 and communicate the joystick position to a controller.

[0025] Referring now to FIG. 2, a bottom view of exemplary paving machine 20 is illustrated. As shown in FIG. 2, the preferred embodiment of the steering sensor is designated generally by reference numeral 40. Preferred steering sensor 40 is adapted to determine the position of preferred steering cylinder 42 and communicate the steering cylinder position to the controller.

[0026] Referring now to FIG. 3, a perspective view of a wheel of exemplary paving machine 20 is illustrated. As shown in FIG. 3, the preferred embodiment of the speed sensor is designated generally by reference numeral 50. Preferred speed sensor 50 is adapted to determine the actual speed of one or more of the one or more wheels 52 of exemplary paving machine 20 and communicate the actual speed of the one or more wheels to the controller. The preferred automatic traction system automatically controls the rotational speed of the one or more wheels 52 of exemplary paving machine 20 in the event that one or more of the one or more wheels lose traction.

[0027] Referring now to FIG. 4, a perspective view of a front wheel well of exemplary paving machine 20 is illustrated. As shown in FIG. 4, the preferred automatic traction system comprises a valve such as Front-Wheel-Assist (FWA) valve 60. Preferred FWA valve 60 is adapted to be moved between an open position and a closed position and is in fluid communication with one or more of the one or more wheels 52. Preferred FWA valve 60 may be either manually or automatically moved between the open position and the closed position. In certain preferred embodiments of the automatic traction system, preferred FWA valve 60 has a paving machine speed threshold. In other preferred embodiments of the automatic traction system, the preferred valve comprises flow sharing or Posi-Lock valve 62 (see FIG. 5). In still other preferred embodiments, Posi-Lock valve 62 and Front-Wheel-Assist valve 60 are moved to the open position for a period of time in the event the actual speed is not within a tolerance of the target speed and the paving machine speed threshold is not exceeded. In the preferred embodiments of the automatic traction system, the period of time may be predetermined. Preferably, the period of time is approximately two (2) seconds. More preferably, the period of time is approximately one (1) second. In other preferred embodiments of the automatic traction system, Posi-Lock valve 62 and FWA valve 60 move to the closed position after the period of time. It is contemplated within the scope of the invention that the period of time and the tolerance may be pre-determined.

[0028] Referring now to FIG. 5, a partial sectional top view of the engine compartment of exemplary paving machine 20 is illustrated. As shown in FIG. 5, the preferred automatic traction system comprises a Posi-Lock valve and a controller. The preferred Posi-Lock valve is designated generally by reference numeral 62, and the preferred controller is designated generally by reference numeral 70. Preferred controller 70 is adapted to communicate with the joystick sensor, the steering sensor, the speed sensor, and the valve. Preferred controller 70 is also adapted to determine a target speed based on the joystick position and the steering cylinder position and determine whether the actual speed is within the tolerance of the target speed. In certain preferred embodiments of the automatic traction system, the tolerance is within approximately twenty-five percent (25%) of the target speed. In other preferred embodiments of the automatic traction system, the tolerance is within approximately ten (10%) of the target speed.

[0029] The invention also comprises a method for controlling the movement of a paving machine having a steering cylinder, one or more wheels, and a joystick. The preferred method comprises providing an automatic traction system as described and claimed herein. The preferred method also comprises moving the valve between the open position and the closed position. In other preferred embodiments, the method further comprises determining a target speed, comparing the actual speed with the target speed, determining if the actual speed is within a tolerance of the target speed, and comparing the actual speed with a paving machine speed threshold.

[0030] Referring now to FIG. 6, a flow chart of another preferred method for controlling the movement of a paving machine having a steering cylinder, one or more wheels, and a joystick is illustrated. As shown in FIG. 6, the joystick position is determined by the joystick sensor and communicated to the controller, and the steering cylinder position is determined by the steering sensor and communicated to the controlled. Based on the joystick position and steering cylinder position inputs, the controller calculates the target speed. The actual speed of the one or more wheels is then determined by the speed sensor and communicated to the controller. The controller then determines if the actual speed of the one or more wheels is within the tolerance of the calculated target speed. If the actual speed of the one or more wheels is within the tolerance of the calculated target speed, the preferred automatic traction system takes no action. If, on the other hand, the actual speed of the one or more wheels is not within the tolerance of the calculated target speed, then the controller determines whether the paving machine speed is below the threshold to allow front wheel assist. If the machine speed is not below the threshold to allow front wheel assist, then the preferred automatic traction system takes no action. If, on the other hand, the machine speed is below the threshold to allow FWA, then the preferred automatic traction system engages the Posi-Lock and the FWA valves for a period of time.

[0031] In operation, several advantages of the preferred embodiments of the automatic traction system are achieved. For example, the preferred embodiments of the invention claimed herein provide an apparatus and method for an automatic traction system that automatically controls the movement of a paving machine in the event one or more wheels lose traction. The preferred embodiments of the invention claimed herein also provide an apparatus and method for an automatic traction system that automatically engages and/or disengages a Posi-Lock valve in the event one or more wheels lose traction. The preferred embodiments of the invention claimed herein further provide an apparatus and method for an automatic traction system that automatically engages and/or disengages a Front-Wheel-Assist (FWA) valve in the event one or more wheels lose traction. The preferred embodiments of the invention claimed herein still further provide an apparatus and method for an automatic traction system that automatically determines when one or more wheels lose traction. In addition, the preferred embodiments of the invention claimed herein provide an apparatus and method for an automatic traction system that automatically compares the actual rotational speed of a wheel against a calculated target rotational wheel speed. Further, the preferred embodiments of the invention claimed herein provide an apparatus and method for an automatic traction system that is not undesirably labor-intensive and subject to human error and delays. Still further, the preferred embodiments of the invention claimed herein provide an apparatus and method for an automatic traction system that minimizes or eliminates human error. The preferred embodiments of the invention claimed herein also provide an apparatus and method for an automatic traction system that does not result in undesirable holes or ruts in the event one or more wheels lose traction. The preferred embodiments of the invention claimed herein further provide an apparatus and method for an automatic traction system that does not result in excessive tire wear. The preferred embodiments of the invention claimed herein still further provide an apparatus and method for an automatic traction system that is not undesirably unsafe, i.e. the operator does not need to remove his hands from the paving machine's motion controls such as the steering wheel or directional joystick in the event one or more wheels lose traction.

[0032] Although this description contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments thereof, as well as the best mode contemplated by the inventors of carrying out the invention. The invention, as described herein, is susceptible to various modifications and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.