초록 ▼

A controller is described for limiting the rate and acceleration of a device positioned by at least one actuator which responds to a sequence of position commands separated by time intervals incorporating a subtractor for taking the difference of two consecutive position commands to provide a differ

A controller is described for limiting the rate and acceleration of a device positioned by at least one actuator which responds to a sequence of position commands separated by time intervals incorporating a subtractor for taking the difference of two consecutive position commands to provide a difference signal in vector form, means for determining the magnitude of the difference signal, a comparator for comparing the magnitude of the difference signal with a predetermined value, a switch for coupling the desired position command to the actuator at times the magnitude of the difference signal is less than or equal to the predetermined value, two dividers, two multipliers, an adder and normalizer for providing a new position command between the past command and the desired position command at times the magnitude of the difference signal exceeds the predetermined value. The acceleration is limited after the rate is limited by subtracting the latest position command from the prior position command to determine a new difference signal of the latest time interval which is subtracted from the difference signal of the previous time interval to determine the change in difference signal in vector form between two consecutive time intervals indicative of acceleration. A new position command is arithmetically generated by the use of a comparator, divider, two multipliers, two adders and a normalizer at times the magnitude of the change exceeds a predetermined value to provide a new position command which is both rate limited and acceleration limited. The invention overcomes the problem of actuators driving a device into gimbal stops and provides a means for damping device oscillations about a desired position.

대표청구항 ▼

Apparatus for controlling the rate of movement of a device positioned by at least one actuator being responsive to each of a sequence of position commands separated by discrete time intervals comprising: first means for determining the magnitude of the difference between first and second position co

Apparatus for controlling the rate of movement of a device positioned by at least one actuator being responsive to each of a sequence of position commands separated by discrete time intervals comprising: first means for determining the magnitude of the difference between first and second position commands to provide a first signal indicative of the distance between said first and second position commands, second means for comparing said first signal with a predetermined constant, third means for coupling said second position command to said device at times said first signal is less than or equal to said predetermined constant, fourth means for generating a scaling factor as a function of said first signal and said predetermined constant, fifth means for multiplying said scaling factor by the difference vector formed by the subtraction of said first and second position commands to form a shortened difference vector, sixth means for adding said shortened difference vector to said first position command to form a third position command intermediate said first and second position commands, and seventh means for coupling said third position command to said device at times said first signal is greater than said predetermined constant.