Method for compensating for coriolis, centrifugal and gravitational couples in a movement simulator and system comprising a movement simulator

A method for compensating for disturbing torques for a movement simulator, said simulator including joints controlled by effector members about axes j as a function of movement set points θrj on the axes, each effector member of a specific given axis of the effector member receiving a command Uj and a sensor for the axis measuring θj, the action of the effector member about said axis j, the simulator being in a system including, for each axis, a control law with a monovariable corrector block in a feedback loop, said monovariable corrector block of transfer function Corr(q−1) receiving as an input a signal of difference between the set point θrj and the measurement θj for the corresponding axis and producing as an output the command Uj,

• wherein the disturbing torques are Coriolis, centrifugal and gravitational torques and wherein, for each axis, a control law is implemented, which includes, in addition to the monovariable corrector block per axis, a non-linear and multivariable compensation law combined to the monovariable correctors, the compensation law calculating, as a function of the command Uj, an estimation {circumflex over (P)}j(t) of the disturbing torques, said estimation {circumflex over (P)}j(t) being injected into the command Uj sent to the effector member, to compensate for the disturbing torques, and
• wherein the estimation {circumflex over (P)}j(t) of the disturbing torques being calculated based on the value of an error signal εj(t), which is a version of the command Uj filtered by a transmittance filter H(q−1) intended to eliminate at least the direct component from the command, and the movement simulator is previously modelled in order to obtain a dynamic model affinely expressing the torques with respect to a set of base parameters % according to a matrix relation of the type:
• ϕjT(θ, {dot over (θ)}, {umlaut over (θ)})χjthe index j corresponding to the different axes, a sub-set αj of the base parameters corresponding to disturbing torques having a level higher than a determined disturbance threshold is determined, following to the previous modelling of the simulator, the estimation {circumflex over (P)}j(t) of the disturbing torques being calculated by:
• {circumflex over (P)}j(t)=ϕjT(θ, {dot over (θ)}){circumflex over (α)}j, and
• wherein the estimations of the sub-sets of base parameters are calculated in line by an iterative equation:
• {circumflex over (α)}j(t+1)={circumflex over (α)}j(t)+μjϕFjT(t)εj(t)
• with ϕFj(t)=H(q−1)T(q−1)ϕ1(t)
• the vector elements ϕjT(t) being filtered by Hj.Corrj.Gj./(1+Cj.Hj) to obtain the vector ϕFjT(t),
• T being defined by the relation (1+Corr(q−1)L(q−1))·T(q−1)=Corr(q−1)L(q−1), with Lj(q−1) the discrete transmittance of the transform of the product
• 1
• J
• j
• ⁢
• 1
• S
• in the case of a sampled system where Jj are the inertias and μj is a defined positive real square matrix serving as an adjustment parameter for the speed of convergence of the estimation.