Process for measuring and controlling extension of scissor linkage systems
First Claim
1. An automated method, performed by a control system of a scissor linkage system, for controlling the position of a platform which is movable only along a first axis by an actuatable scissor linkage mechanism comprising an actuator and a link coupled to the actuator, the link having one end that is movable only along a second axis orthogonal to the first axis during operation of the actuator, comprising the following steps:
- receiving data representing a target platform position along the first axis;
calculating an actuator target position as an inverse kinematics function of said target platform position; and
controlling the actuator to move to said actuator target position, which causes the one end of the link to move along the second axis and the platform to move along the first axis.
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Accused Products
Abstract
A process for measuring and controlling the position and velocity of one moving part of a scissor lift device through the measurement of another moving part of the scissor lift device. The position and velocity of the moving part (e.g., a platform of the scissor lift device) are computed using kinematics and Jacobian functions that define the position and velocity in terms of the measured degree of freedom. The process provides continuous, closed-form computation of the position and velocity of a platform carried by a scissor linkage mechanism during the latter'"'"'s extension, which enables applications for motion sensing and control of linkage extension types of systems.
25 Citations
20 Claims
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1. An automated method, performed by a control system of a scissor linkage system, for controlling the position of a platform which is movable only along a first axis by an actuatable scissor linkage mechanism comprising an actuator and a link coupled to the actuator, the link having one end that is movable only along a second axis orthogonal to the first axis during operation of the actuator, comprising the following steps:
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receiving data representing a target platform position along the first axis; calculating an actuator target position as an inverse kinematics function of said target platform position; and controlling the actuator to move to said actuator target position, which causes the one end of the link to move along the second axis and the platform to move along the first axis. - View Dependent Claims (2, 3, 4)
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5. A scissor linkage system comprising:
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a frame; a scissor linkage mechanism comprising a first link that is pivotably coupled to said frame at a first pivot point and a second link that is pivotably coupled to said first link at a second pivot point; a platform coupled to and supported by said scissor linkage mechanism; an actuator having first and second actuator positions, said first and second links being rotatable relative to each other about said second pivot point and said scissor linkage mechanism being extendible in a direction away from said frame when the position of said actuator changes from said first actuator position to said second actuator position, said platform being in first and second platform positions when said actuator is in said first and second actuator positions respectively; and a computer system comprising memory storing an actuator control program for controlling said actuator, and one or more processing units configured to execute operations in accordance with said actuator control program in response to receipt of data representing a target platform position, said operations comprising; (a) calculating a target actuator position as an inverse kinematics function of said target platform position; and (b) controlling said actuator to move to said second actuator position when said target platform position is said second platform position. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12)
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13. A scissor linkage system comprising:
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a frame; a scissor linkage mechanism comprising a first link that is pivotably coupled to said frame at a first pivot point and a second link that is pivotably coupled to said first link at a second pivot point; a platform coupled to and supported by said scissor linkage mechanism; an actuator having first and second actuator positions, said first and second links being rotatable relative to each other about said second pivot point and said scissor linkage mechanism being extendible in a direction away from said frame when the position of said actuator changes from said first actuator position to said second actuator position, said platform being in first and second platform positions when said actuator is in said first and second actuator positions respectively; an actuator position sensor that is coupled to said actuator and configured to output current actuator position data representing a current position of said actuator; and a computer system comprising memory storing an actuator control program for controlling said actuator, and one or more processing units capable of executing operations in accordance with said actuator control program in response to receipt of said current actuator position data and data representing a target platform velocity, said operations comprising; (a) calculating a target actuator velocity as an inverse Jacobian function of said current actuator position and said target platform velocity; and (b) controlling said actuator to move toward said second actuator position at said target actuator velocity. - View Dependent Claims (14, 15, 16, 17)
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18. A scissor linkage system comprising:
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a frame; a scissor linkage mechanism mounted to said frame; a platform coupled to and supported by said scissor linkage mechanism, said platform being movable away from said frame when said scissor linkage mechanism is extended; an actuator coupled to said scissor linkage mechanism for causing said scissor linkage mechanism to extend when said actuator is moved in an actuation direction; means for receiving data representing a target platform position; means for calculating an actuator target position as an inverse kinematics function of said target platform position; and means for controlling said actuator to move to said target actuator position. - View Dependent Claims (19, 20)
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Specification