The present invention relates to a variable rigidity robot joint system including a first driving module and a second driving module generating torque which is rotated on a first direction, a first rotating module changing rotations of the first driving module and the second driving module into rotations on a second direction intersecting the first direction when the first and second driving modules rotate in directions in which a joint is rotated in a same direction, thereby rotating the joint, a rigidity-providing member providing rigidity by elastically supporting a rotational movement of the first rotating module on the second direction, and a second rotating module changing rotations of the first driving module and the second driving module into a linear motion in the first direction when the first and second driving modules rotate in directions in which the joint is rotated in different directions.

An actuator includes a casing, an output disc, a transmission component, a cable, a power source, and a tension adjustment assembly. The output disc and the transmission component are rotatably disposed on the casing. The cable is disposed through the transmission component and connected to the output disc. The power source can drive the transmission component. The tension adjustment assembly includes a lever, an elastic component, and a slidable component. The lever has a first end and a second end opposite to each other. The first end is connected to the cable. The elastic component is connected to the casing and the second end of the lever. The slidable component is in contact with a portion of the lever located between the first end and the second end, and is slidable along the lever to change its position to adjust a tension of the cable.

Safety is one of the most important factors in the robot interaction with unknown and dynamic environments. Recent studies have shown that the use of compliant components as a solution to the safety issue, especially in the physical human-robot interaction. To overcome performance degradation caused by including compliant elements into the systems, variable stiffness approaches have been introduced at the cost of an extra actuator. A variable stiffness gripper is presented. Embodiments of the disclosed gripper may have, for example, with two parallel fingers (jaws). Compliance of the system may be generated by using magnets as the nonlinear springs. Based on the presented design, the position and stiffness level of the fingers can be adjusted simultaneously by changing the air gap between the magnets.

A variable stiffness joint and method to alter the stiffness of the joint with multiple stiffness levels is described wherein a plurality of stiffness bits (m) are used for enabling 2 m stiffness level variations for the joint. Each stiffness bit comprises an elastic element in mechanical connection with a clutch (21, 22, 23). The joint revolves with zero stiffness level when all the clutches (21, 22, 23) are disengaged whereas a clutch (21, 22, 23) involves one of the elastic elements which alter the stiffness of the joint. Engaging other clutches (21, 22, 23) involve more elastic elements for altering the joint stiffness and the resultant joint stiffness is determined by adding the stiffness values of all the involved springs (6, 7, 8).

A tensioning set comprises an output member. A magnetorheological fluid clutch apparatus is configured to receive a degree of actuation (DOA) and connected to the output member, the magnetorheological fluid clutch apparatus being actuatable to selectively transmit the received DOA through the output member by controlled slippage. A tensioning member is connected to the output member so as to be pulled by the output member upon actuation of the magnetorheological fluid clutch apparatus, a free end of the tensioning member adapted to exert a pulling action transmitted to an output when being pulled by the output member. The tensioning set, or a comparable compressing set, may be used in systems and robotic arms. A method for controlling movements of an output driven by the tensioning set or compressing set is also provided.

A soft actuator, its working method and robot are provided. The soft actuator includes a power input shaft, and multiple electromagnetic clutches are coaxially installed in series on the power input shaft. A bending elastic part is arranged between the thrust plate of each electromagnetic clutch and the gear frame of the electromagnetic clutch. The bending elastic part is installed on the sleeve of the gear frame and in contact with the baffle of the gear frame. The bending elastic part is connected with the clutch output gear of the electromagnetic clutch through the gear frame. The gear frame is fixedly connected with the clutch output gear and rotates coaxially.

An actuator includes a casing, an output disc, a transmission component, a cable, a power source, and a tension adjustment assembly. The output disc and the transmission component are rotatably disposed on the casing. The cable is disposed through the transmission component and connected to the output disc. The power source can drive the transmission component. The tension adjustment assembly includes a lever, an elastic component, and a slidable component. The lever has a first end and a second end opposite to each other. The first end is connected to the cable. The elastic component is connected to the casing and the second end of the lever. The slidable component is in contact with a portion of the lever located between the first end and the second end, and is slidable along the lever to change its position to adjust a tension of the cable.

The present disclosure provides a biologically-inspired robotic device comprising: a first member; a second member pivotably connected to the first member; one or more actuators; and a coupler/decoupler mechanism (CDC) selectively coupling or decoupling of the one or more actuators to the second member, such that, when the one or more actuators are coupled to the second member, the one or more actuators act to pivot the second member relative to the first member.

In one embodiment, a selectable-rate spring comprises a flexure bar connected to a rotatable shaft, the flexure bar having at least one arched portion. The selectable-rate spring also includes at least one rotational contactor connectable to a link member, wherein the rotational contactor rotates about an axis while maintaining contact with the arched portion of the flexure bar. As the rotational contactor rotates, it changes the connection stiffness between the rotatable shaft and the link member.

An example actuator is provided to be used in robots and robotic devices. The actuator includes: a first plate, a second plate, and an elastic element disposed between the first plate and the second plate and including a center portion and an edge portion, the center portion corresponding to a first thickness and the edge portion corresponding to a second thickness larger than the first thickness, a first shear stress associated with the center portion being approximately equal to a second shear stress associated with the edge portion.