Patent ID: 6922607

Claim:
A numerically controlled method for moving an object to be controlled along a predetermined locus by controlling respective control axes in a joint space, the method comprising: approximating said locus by defining a spatial polynomial in a work space, said spatial polynomial having a parameter λ(0≦λ≦1); obtaining said parameter λ as a function of said time parameter t supposing that a length ΔL i of one of the line elements of a curved line defined by said spatial polynomial is equal to a movement distance of moving said object to be controlled within a time Δt i on the basis of a predetermined speed function F(t) having a parameter of time t, by dividing said parameter λ by sequences of numbers O=λ 0 <λ 1 <λ 2 <λ 3 < . . . <λ i < . . . <λ n =1; producing said time parameter polynomial by entering λ=α(t) thus obtained into said spatial polynomial and converting said parameter λ into said function of time parameter t; producing a position command, a velocity command and an acceleration command from said converted time parameter polynomial; converting and delivering said produced position command, said velocity command and said acceleration command to said respective control axes in said joint space; producing control commands for said respective control axes in said joint space from said position command, said velocity command, and said acceleration command on the basis of said time parameter polynomial, converted and distributed to said control axes in said joint space; and moving said object to be controlled along said locus, while controlling said respective control axes in said joint space on the basis of said control commands.