The University of British Columbia

Real N Frenette

Peter D Lawrence

Nariman Sepehri

Danley C Chan

A method and apparatus for controlling the movement of an end point of an articulated arm in the x, y and z directions using a manually operated resolved motion control by controlling the component of velocity of the end point in each of the x, y and z directions to change by the same amount for a given change in the component of displacement of the manual controller in the respective x, y and z directions provided the total displacement in the selected x, y or z direction is less than a preselected displacement in the respective x, y or z direction and the end point is within a preselected work space. The velocity of the end point in any one of the x, y and z directions when the total displacement of the manual controller in the respective x, y or z direction is greater than the preselected displacement changes at a ratio of end point speed to change in the component of controller displacement that is independent of the ratio of controller displacement to end point speed in at least one of the other of the x, y or z directions.

Resolved motion velocity control

A hydraulic control system for controlling the motion of a double acting hydraulic actuator determines the flow to and from the actuator in accordance with

Hydraulic control system with pressure responsive rate control

A hydraulic control system for a multi-linked manipulator arm monitors the desired flow of hydraulic fluid to each of the actuators for the links of the manipulator, and when the desired flow to any one or more of the actuators exceeds the available flow to the respective actuators, the flows to all the actuators are reduced on the basis of a scaling factor based on the ratio of the available flow to the desired flow of that actuator having the maximum ratio of its desired to available flows so that the relative speed of all the actuators for manipulating the arm is maintained. In some cases some actuators may have higher priority than others and a second scaling factor in which such priorities have been applied may also have to be applied to the flows to reduce the relative speeds of all actuators.

Proportional hydraulic control

An articulated arm employs a controller to generate .delta.r, .delta..THETA. and .delta.z signals for controlling the movement of the arm in r, .THETA. and z directions to product movement of an end point from an initial location along a desired path toward a desired location. The actual location is determined by sensing the relationships between the arm segments and determining the actual location of the end point. The actual location is continuously compared with the desired location represented by the r, .THETA. and z signals and, if the difference between the actual location and desired location exceeds preselected limits, the .delta.r, .delta..THETA. and .delta.z are scaled down thereby redefining the desired location to ensure that the actual arm movement does not lag an unacceptable amount relative to the desired location.

Growing community of inventors

Vancouver, Canada

Real N Frenette