11 accepted papers
This paper presents the design, control, and experimental validation of a lightweight hip exoskeleton for walking assistance. By integrating quasi-direct drive actuators, single-piece stainless steel frames, and passive revolute joints, the device achieves a high torque-to-mass ratio while maintaini…
Accurate torque estimation in robotic actuators with harmonic drives is challenging due to nonlinear hysteresis and efficiency losses, often necessitating external torque sensors. This paper presents a learning-based torque estimation method that leverages encoder-derived features and mechanical com…
This paper presents the design and experimental validation of a torque-controlled robotic wrist for peg-in-hole tasks. The proposed wrist features a serial pitch-yaw joint configuration that enhances dexterity while maintaining compactness. The design integrates stepper motors, harmonic geartrains,
Series elastic actuators (SEAs) achieve output torque and stiffness control by managing the deformation of a spring arranged between the motor and the output. SEAs are ideal for tasks involving human-robot interaction and unstructured environments. The stiffness, size, and torque capacity of the spr
Various sensorized grippers have been developed to handle delicate objects safely. These grippers have sensors mounted on their fingers’ surface that provide direct force measurements. However, multiple sensors are often required on one finger, leading to significant sensor placement and wire routin…
A haptic device is used to transmit impedance to a human user to mimic the impedance of a virtual or real environment. Existing haptic devices use serial or parallel robots to deliver impedance in multiple dimensions. These robots usually have nonconstant Jacobian matrices that result in poor dynami
Accurate and wide-range stiffness control is important for safe human-robot interaction. Accurate stiffness control can be better achieved using series elastic actuators (SEAs) than conventional rigid actuators. However, the stable range of virtual stiffness rendered by SEAs is limited by the stiffn
Industrial arm-type robots have multiple degrees-of-freedom (DoFs) and high dexterity but the use of the roll-pitch-roll wrist configuration yields singularities inside the reachable workspace. Excessive joint velocities will occur when encountering these singularities. Arm-type robots currently don…
Compared with stiff actuators, series elastic actuators (SEAs) can render more accurate output torque and stiffness. Hence, SEAs are suitable for robots that need to interact safely with human or properly with the actual or virtual environment. Many existing rotary SEAs are bulky and not suitable fo
Controlling the contact force on workpieces has been a challenging task for industrial grinding/deburring operations. Its realization often requires a grinding spindle with a multi-axis force sensor and controller feedback. The spindle needs to frequently vary its position in order to maintain a con…
Powered exoskeletons can provide motion enhancement for both healthy and physically challenged people. Upper limb exoskeletons are required to have multiple degrees-of-freedom and can still produce sufficient force to augment the upper limb motion. The design using serial mechanisms usually results…