System to control and/or to synchronize the motion of two shafts

A system to control an element via an input device by delivering a feedback force from the element to the input device, the system comprising:

• an input shaft (110, 210) on which the input device is mounted,
• a remote shaft (120, 220) on which the element is mounted, wherein the remote shaft (120, 220) and the input shaft (110, 210) are spatially separated and each shaft (110, 120;
• 210, 220) is rotatably mounted in a respective frame member (111, 121;
• 211, 221) against a spring force,
• an angle sensor (113, 123;
• 213, 223) provided to each shaft (110, 120;
• 210;
• 220) each angle sensor being configured to measure a rotational position of the respective shaft (110, 120;
• 210, 220) with respect to the respective frame member (111, 121;
• 211, 221),
• an electronic control unit to which output signals (115, 125;
• 215a, 225a) of the angle sensors (113, 123;
• 213, 223) are transmitted,
• a first torque actuator (114, 214) mounted on the input shaft (110, 210), and
• a second torque actuator (124, 224) mounted on the remote shaft (120, 220),
• wherein the electronic control unit is configured to control the torque actuators in such a manner that torques exerted to the input shaft (110, 210) and to the remote shaft (120, 220) are both functions of a difference of angular positions (θ1, θ2) of the input shaft (110, 210) and of the remote shaft (120, 220) as measured by the angle sensors (113, 123;
• 213, 223), wherein the angular positions (θ1, θ2) are weighted by a virtual spring constant (k) that emulates a mechanical connection between the input shaft (110, 210) and the remote shaft (120, 220).