Patent Application
20080023250
An exemplary embodiment of a machine 10 is illustrated in
Both forward and rear traction devices 12, 14 may include one or more wheels located on each side of machine 10 (only one side shown). Alternatively, forward and/or rear traction devices 12, 14 may include tracks, belts, or other traction devices known in the art. Any of forward and rear traction devices 12, 14 may be driven and/or steerable. Frame 16 may connect forward traction device 12 to rear traction device 14 by way of, for example, an articulated joint 20. It is contemplated that machine 10 may be steered by causing forward traction devices 12 to rotate about a vertical axis 24, by driving the forward and/or rear traction devices 12 located on opposing sides of machine 10 at differing speeds and/or in different directions, and/or by causing a front portion of machine 10 to be rotated about articulated joint 20 relative to a rear portion. These steering actions may be affected hydraulically, electrically, pneumatically, mechanically, or in any other manner in response to a steering input.
Operator station 22 may house a control console 26. In particular, as illustrated in
Base member 30 may embody a generally rectangular housing configured to support operator interface device 38 on an upper portion thereof. Base member 30 may enclose and protect the internal mechanisms of operator interface device 38, as well as the electrical and/or hydraulic connections between operator interface device 38 and external motors or electronic control modules (not shown) located elsewhere on machine 10. As indicated above, base member 30 may mount to armrest 32 via fastening devices 34.
In one embodiment, operator interface device 38 may be a single axis lever (SAL). It is contemplated, however, that, instead of a SAL, operator interface device 38 may alternatively include a multi-axis lever, a full or partial steering wheel, or other operator interface devices that require at least a generally transverse movement input from the operator for steering actuation. For the purposes of this disclosure, the transverse direction and a forward direction may be related and defined with respect to seat 28 and/or the location and movement of an operator's forearm. For example, seat 28 may include a substantially vertical plane of symmetry 33, about which seat 28 is generally horizontally symmetric. The forward direction, in this example, may be substantially parallel with plane 33 and substantially parallel with un upper surface of armrest 32 upon which an operator's fore arm rests during operation of machine 10. With respect to the operator's forearm, when the operator is properly situated within seat 28, the forearm is kept in contact with armrest 32 along the length of armrest 32, and the upper arm is rotated about the shoulder joint in a plane substantially parallel to plane 33, the forearm movement may be in the forward direction. Correspondingly, the transverse direction may be substantially orthogonal to plane 33 and parallel with the upper surface of armrest 32, as indicated by arrows 35.
Operator interface device 38 may control a steering motion of machine 10. In particular, a left side-tilting movement of operator interface device 38 away from a neutral axis 40 (viewed from an operator's perspective) about pivot axis 42 may cause machine 10 to steer to the left. A right side-tilting movement of operator interface device 38 away from neutral axis 40 about pivot axis 42 (viewed from the operator's perspective) may cause machine 10 to steer to the right. Operator interface device 38 may be spring biased to return to neutral axis 40 when released by the operator or, alternatively, may include a braking mechanism (not shown) to hold operator interface device 38 in an actuated position when released. It is contemplated that an actuation position or speed of operator interface device 38 may correspond with an angular position of forward traction devices 12, a steering speed of forward traction devices 12, an angular position of articulation joint 20, or an orienting speed of articulation joint 20.
Operator interface device 38 may have a predefined range of motion. That is, operator interface device 38 may be movable away from neutral axis 40 in a first transverse direction (i.e., to the left when viewed from the operator's perspective) a first predetermined angle, and away from neutral axis 40 in a second transverse direction (i.e., to the right when viewed from the operator's perspective) a second predetermined angle. In one embodiment, the first and second predetermined angles may be substantially equal, with the total range of motion being about 70-90 degrees. For optimal operator comfort, however, operator interface device 38 may be limited to a maximum tilt angle of 40 degrees to the left and 40 degrees to the right (e.g., +/− 40 degrees). This range of motion may allow sufficient steering modulation, even at high speeds, without undue operator fatigue.
Operator interface device 38 may be oriented away from the operator in the forward direction to facilitate the +/− 40 degree range of motion and operator comfort. That is, in order to minimize side-to-side movement of an operator's arm during the tilting of operator interface device 38 through the 40 degrees, a pivot axis 42 of operator interface device 38 may be angled downward away from the upper surface of armrest 32 by an angle θ, as illustrated in
It is contemplated that operator interface device 38 may alternatively include a multi-axis controller. If multi-axis controllers are implemented within control console 26, operator interface device 38 may also be movable in the forward direction to initiate a first function of machine 10 (i.e., forward/reverse travel and/or acceleration of machine 10), in the transverse direction to control steering, and, possibly, in a direction between the forward and transverse directions such that both the first function and steering are initiated. In this arrangement, at least one of the forward and transverse pivot axis of the multi-axis controller may be angled downward away from the upper surface of armrest 32 in the forward direction by angle θ.
Operator interface device 38 may be cantilevered such that a transverse plane of motion 44 (e.g., the plane formed by the arc-like movement of operator interface device in the transverse direction) is axially offset from the device's rotation joint 46. Specifically, operator interface device 38 may include a handle portion 38a, and a support member 38b fixedly connected to handle portion 38a. Support member 38 may be received at one end by rotation joint 46, which is located at a position axially spaced apart from the transverse plane 44. In this embodiment, support member 38b may extend along both an axial direction of handle portion 38a and along pivot axis 42 to rotation joint 46, thereby forming an L-shape. This configuration may help to minimize the spatial footprint of operator interface device 38 within station 22.
The distance from handle portion 38a to pivot axis 42 may be limited for operator comfort. That is, in order to minimize side-to-side movement of the operator's arm, the distance from handle portion 38a to pivot axis 42 may be limited to less than a predetermined distance “d”. As the distance “d” decreases, the arc length through which the operator's arm must move to accomplish the same steering input angle may likewise decrease. In one embodiment “d” may be limited to less than about 15 mm.
Operator interface device 38 may control a second machine function. Specifically, operator interface device 38 may include one or more transmission input controls 48 located on handle portion 38a. These input controls may affect a transmission operation such as, for example, transmission shifting between output gear ratios, selection of a maximum desirable output gear ratio, transmission directional changes, and other transmission operations known in the art.
The disclosed control console may be applicable to any machine requiring operator input to steer the machine. The disclosed control console may effectively reduce operator fatigue by providing an ergonomically located operator interface device have extensive modulation capacity. The operation of control console 26 will now be explained.
During operation of machine 10, an operator may control multiple machine functions with the same hand, with little hand or arm movement. Specifically, while the operator's arm is positioned on armrest 32, both steering and transmission control may be accomplished. For example, a steering input may be generated by transversely rocking operator interface device 38 to the right through an angle up to about 40 degrees and to the left through an angle up to about 40 degrees. In addition, transmission controls 48 may be manipulated to indicate a desired change in transmission operation. Once the steering input and/or transmission input has been received, the control module may determine a steering angle output and/or a transmission output command signal to affect the desired steering angle or transmission operation.
To relieve operator fatigue, operator interface device 38 may be located in an ergonomic manner. For example, pivot axis 42 may be angled relative to the upper surface of armrest 32 by about 12 degrees such that the axis about which operator interface device tilts runs approximately through the elbow joint of an operator. This orientation combined with the distance limitation of handle portion 38a to pivot axis 42 may minimize the movement required of an operator to affect the desired steering.
The location and design of handle portion 38a relative to pivot joint 46 may reduce the spatial footprint of control console 26. In particular, because the pivot joint and associated electronics are axially spaced apart from handle portion 38a, these components may be located within armrest 32 or another location out of the way of operator movements.
Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims.
