Motor vehicles – Manually actuated controlling devices
Reexamination Certificate
2001-10-15
2004-01-27
Dickson, Paul N. (Department: 3616)
Motor vehicles
Manually actuated controlling devices
C074S48000R, C414S005000, C414S703000, C172S442000, C341S020000, C345S161000
Reexamination Certificate
active
06681880
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a control element or control lever for the manual control of the movements of a system to be controlled.
BACKGROUND OF THE INVENTION
It is known to use a control lever in the control of a mechanism or system, such as a lever or a joystick which may be pivoted about one or two axes. Such control levers permit a control of a mechanism with two degrees of freedom. For example, EP-A-0 981 078 describes a control lever in the form of a joystick which can be moved by means of a universal joint in two directions, to the front and the rear as well as to the left and the right. On the grip of the control lever there are two electric push-button switches for generating further control signals.
Additional control elements, such as rollers or electrical push-button switches can be integrated into a control lever for the control of the movement in more than two degrees of freedom, such as in a spatial dimension. But the operation may become complicated and ergonomically less than optimal.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a control lever which permits control of more than two and up to six degrees of freedom.
An object of the present invention is to provide such a control lever which has only one handgrip, and which can be operated in all degrees of freedom, without the need for actuating additional activating elements.
An object of the present invention is to provide such a control lever which has a simple design and which operates ergonomically.
These and other objects are achieved by the present invention, wherein a control lever includes a handgrip, and is configured as a control lever which can be operated by an operator. The handgrip is fastened to a platform, so that the platform follows the movement of the handgrip, or so that forces applied to the handgrip are transmitted to the platform. At least six connecting elements are arranged between the platform and a fixed console. Furthermore, transducers or sensors are provided for detecting changes in length of the connecting elements or for sensing tension and compression forces applied to the connecting elements. Forces in six degrees of freedom may be applied to the handgrip—in three different translational directions and about three different axes of rotation. The length signals or force signals are associated with the connecting elements.
From the length signals or the force signals three coordinates and three orientation angles can be determined which represent the position of the platform with respect to the console or which represent the force vectors and moment vectors applied to the handgrip. The sensor signals represent unequivocally the position of the handgrip or the forces and moments applied to the handgrip. In the calculation of the coordinates known methods can be applied, such as described by Hebsacker, M., in The Definition of the Kinematic of the Hexaglide.—“Methods for the Definition of Parallel Machine Tools”, VDI reports No. 1427, 1998.
The length or force sensor signals are evaluated by a control unit and utilized for the control of the movement of the system to be controlled. The control unit calculates the immediate position of the handgrip or the forces and moments applied to the handgrip from the sensor signals, and transmits corresponding control signals to the system that is to be controlled.
Thus, the control lever of the invention can be used for the manual control of movement of a system to be controlled, for example, as well as a virtual system. With only one control lever, movement of a system can be controlled in up to six degrees of freedom, without the need for the actuation of additional switches and the like. Thus, the system can be controlled in a simple and ergonomically favorable way.
Preferably, the connecting elements are arranged in the form of a hexapod. Hexapods have been used, for example, in measurement implements for determining the accuracy of position of machine tools (DE-A-35 04 464), in motorized coordinate measurement implements (DE-A-197 20 049) and in robot kinematics. A hexapod is an arrangement of connecting elements, that make possible movement in six degrees of freedom, and which may include six or more (for example, eight) connecting elements. By using a hexapod arrangement in connection with a control lever it is possible to move the handgrip and with it the platform in six degrees of freedom and to convert the movements unequivocally into control signals. The handgrip can be pivoted, for example, to the side in two directions, rotated about its axis, shifted to the side in two directions, and shifted inward and outward in the direction of its axis. If force sensors are used, the movements of the handgrip may be so small that they cannot be sensed by the operator. In this case the operator will not perform a definite spatial repositioning of the handgrip, but will apply forces to the handgrip that correspond to the desired control signals. Such a versatile actuation of a handgrip is not possible with control levers previously known.
The invention can be used to control mechanisms with more than two degrees of freedom. A preferred application is in connection with an attachment interface or hitch for coupling of implements to a utility vehicle, as is described in DE-A-199 51 840. This attachment interface includes six hydraulic cylinders arranged in a hexapod between a tractor and a coupling frame. The hydraulic cylinders can be controlled by the control lever of the present, wherein the signals of each length or force sensor of the control lever hexapod is used to control a corresponding hydraulic cylinder of the attachment interface hexapod.
The present invention could also be used as a so-called “three-dimensional mouse” and for the control of virtual movements, such as could be displayed on a monitor.
Preferably, the connecting elements are telescoping and are arranged in a hexapod. Each telescoping leg includes two telescoping rods that can be shifted axially relative to each other, and which have free ends which engage the platform or the console, which are free to pivot in all directions, and which are attached at attachment points which are located near the corners of a triangle. The telescoping legs are equipped with length or distance sensors which provide length signals corresponding to the length of the associated telescoping leg.
Each telescoping leg may include a cylinder housing open at both ends and which engages a slidable telescoping rod. The telescoping rods are supported by springs in their central position. By actuation of the control lever against the force of the springs, the length of the spring legs can be varied. If the control lever is released, the platform and with it the control lever returns to the central position. Alternatively, or in addition to the springs, each telescoping rod can be guided by a friction fit in the cylinder housing, so that for a shift in length friction forces must be overcome.
The length sensors may be sliding variable resistance type sensors. But it is also possible to employ, for example, inductive, capacitative or opto-electronic length sensors.
According to a further preferred embodiment, the connecting elements are generally rigid in their length, so that they can neither be extended nor shortened by the application of axial forces. The tension and compression forces applied to the connecting elements by the actuation of the handgrip are measured by force sensors. Force sensors may, for example, be strain gages or piezo-electric sensors.
The attaching point of the connecting elements at the platform and/or at the console are located preferably near the corners of an equilateral triangle. Two connecting elements are connected near each corner, and can be pivoted in two directions. But it may also be appropriate to arrange the connecting joints approximately in the corners of a square or of a hexagon or in some other geometric shape. In a square, for example, two connecting elements can each engage two adjoining corners of the s
Bernhardt Gerd
Elser Jurgen
Fedotov Sergiy
Lang Matthias
Rudik Ruslan
Deere & Company
Dickson Paul N.
Rosenberg Laura B.
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