Haptic hands and grippers, designed to enable skillful object manipulation, are pivotal for high-precision interaction with environments. These technologies are particularly vital in fields such as minimally invasive surgery, where they enhance surgical accuracy and tactile feedback: in the development of advanced prosthetic limbs, offering users improved functionality and a more natural sense of touch, and within industrial automation and manufacturing, they contribute to more efficient, safe, and flexible production processes. This paper presents the development of a two-finger robotic hand that employs simple yet precise strategies to manipulate objects without damaging or dropping them. Our innovative approach fused force-sensitive resistor (FSR) sensors with the average current of servomotors to enhance both the speed and accuracy of grasping. Therefore, we aim to create a grasping mechanism that is more dexterous than grippers and less complex than robotic hands. To achieve this goal, we designed a two-finger robotic hand with two degrees of freedom on each finger; an FSR was integrated into each fingertip to enable object categorization and the detection of the initial contact. Subsequently, servomotor currents were monitored continuously to implement impedance control and maintain the grasp of objects in a wide range of stiffness. The proposed hand categorized objects’ stiffness upon initial contact and exerted accurate force by fusing FSR and the motor currents. An experimental test was conducted using a Yale–CMU–Berkeley (YCB) object set consisted of a foam ball, an empty soda can, an apple, a glass cup, a plastic cup, and a small milk packet. The robotic hand successfully picked up these objects from a table and sat them down without inflicting any damage or dropping them midway. Our results represent a significant step forward in developing haptic robotic hands with advanced object perception and manipulation capabilities.

The problem of position tracking in teleoperation systems containing latencies and dynamical uncertainties is addressed in this work. In many applications, such as telesurgery, safe interaction with the external environment is a factor which may undermine the synchronization of the positions. For nondestructive contact with the environment, in addition to an errorless steady-state position tracking, the closed-loop system requires to have a response with the least possible overshoot. To this end, a state-feedback controller based upon L1 theory is proposed in this work. The compensator is synthesized utilizing the linear matrix inequality (LMI) technology, and the asymptotic stability of the system is verified employing Lyapunov-Krasovskii functional. Another advantage of the proposed control scheme is that it is robust to asymmetric randomly varying time delays in the communication channels. The L1-based controller is finally compared to the well-known sliding mode controller via simulation, and is proved to outperform it from maximum error point of view, while preserving low steady-state error. The proposed controller is also illustrated to be effective even in the presence of model uncertainties.

This paper presents a new robotic mechanism for ultrasound imaging. The device is placed on a patient's body by an operator, and an ultrasound expert controls the motions of the device to obtain ultrasound images. The paper focuses on the robotic mechanism that performs ultrasound imaging. The design of the mechanism is based on two approaches to produce center of motion for an ultrasound probe. This center of motion which is located on the tip of the probe helps to create clear ultrasound images. Detailed designs, kinematic relationships, prototyping and ultrasound imaging tests are presented. A novel cabling mechanism is developed to create the center of motion required for ultrasound imaging. The mechanism provides all four necessary motions for ultrasound imaging by using two actuators which significantly reduces the weight of the device to make it suitable for portable ultrasound applications. The device has been successfully used for ultrasound imaging of kidney, gallbladder, liver, ovary and uterus of volunteer patients.