Master controller assembly (202) for a robotic surgery system further comprising at least one slave robot assembly (203) comprising a slave surgical grip device (217) able to provide a grip degree- of-freedom of motion lying in a predefined slave grip plane (218), and a control unit (205)； wherein said master controller assembly (202) comprises at least a portable hand-held master input tool (206), said master controller assembly (202) is operatively connected to said slave robot assembly (203)； said master input tool (206) comprises a master tool body (209)； said master tool body (209) comprises a at least one manipulandum surface (210), designed to be hand-held by the surgeon's fingers (211, 212), said master input tool (206) is mechanically unconstrained from said slave robot assembly (203), said at least one manipulandum surface (210) is a convex surface, said master input tool (206) comprises a grip command detector device (213)； comprising an operative portion (214) comprises at least one operative surface (215) suitable to face the surgeon's fingers (211, 212)； said operative portion (214) being operable by said manual command, said manual command being a radially directed pressure action (216) exerted at any point of the operative surface (214)； said master input tool (206) comprises at least one sensing assembly (222) detecting said radially directed pressure action (216), in such way that said radially directed pressure action (216) exerted at any point of said operative surface (215) determines a paired slave grip motion action (221) of said surgical slave grip device (217), said paired grip motion of said surgical grip device (217) being lying in said predefined slave grip plane (218).La présente invention concerne un ensemble contrôleur maître (202) pour un système de chirurgie robotique, comprenant en outre au moins un ensemble robot esclave (203) comprenant un dispositif de préhension chirurgical esclave (217) apte à fournir un degré de liberté de mou
