Staticall V-balanced Direct Drive Robot for Compliance Control Anal Vsis

A stBtlCBl-l-y-bBI-Bnced direct drive robot monlpul-otor with new Brchltecture Is constructed Bt the University of MlnnesotB for stBbll-lty BnBl-ysls of ImpedBnce Control[8,10,11). This mechBnlsm, using B four-bar-l-lnkage, Is designed Without extra counterweights. As B resul-t of the el-lmlnBtlon of the gravity forces on the drive system, smBl-l-er Bctuators [Bnd consequentl-y smBl-l-er Bmpi-ifiers) CBn be chosen. This guBrBntees Bn Bccel-eratlon of 5g without overheBtlng the motors. This mechanism resul-ts In cl-osed-form sol-utlon for the Inverse klnemBtlcs. The cl-osed-form sol-utlons for dynBmlcs Bnd Inverse kinematics hBve been derived. High torque, I-ow speed, brush-l-ess AC synchronous motors Bre used to power the robot. The rel-Btlvel-y "I-Brge" workspBce of this conflgurBtlon Is sultBbl-e for mBnufacturlng tBsks. GrBphlte epoxy composite r7"IBterlBIIs used for the construction of the robot !-Inks. University of Minnesota Direct Drive Robot Manipulator Introduction A staticalLy balanced direct drive arm, with a four-bar-linkage has been designed to compensate for some of the drawbacks of seriaL type (1,2,151 and paraLlelogram type (3,4,20J direct drive arms. Before describing the properties of this arm, some disadvantages and advantages of direct drive arms are discussed here: 1.~. The meneuverlng speed ,of the direct drive arms Is not necesserl~1J greater then the non-direct drive erms. The maximum achlevab~e speed for a given architecture depends on the transmission ratio. The optimum transmission ratio .Is a function of the