This paper introduces a novel robotic gripper, named as the SPD gripper. It features a palm and two mechanically identical and symmetrically arranged fingers, which can be driven independently or by a single motor. The fingertips of the fingers follow a linear motion trajectory, facilitating the grasping of objects of various sizes on a tabletop without the need to adjust the overall height of the gripper. Traditional industrial grippers with parallel gripping capabilities often exhibit an arcuate motion at the fingertips, requiring the entire robotic arm to adjust its height to avoid collisions with the tabletop. The SPD gripper, with its linear parallel gripping mechanism, effectively addresses this issue. Furthermore, the SPD gripper possesses adaptive capabilities, accommodating objects of different shapes and sizes. This paper presents the design philosophy, fundamental composition principles, and optimization analysis theory of the SPD gripper. Based on the design theory, a robotic gripper prototype was developed and tested. The experimental results demonstrate that the robotic gripper successfully achieves linear parallel gripping functionality and exhibits good adaptability. In the context of the ongoing development of embodied intelligence technologies, this robotic gripper can assist various robots in achieving effective grasping, laying a solid foundation for collecting data to enhance deep learning training.

This paper presents a novel underactuated adaptive robotic hand, Hockens-A Hand, which integrates the Hoeckens mechanism, a double-parallelogram linkage, and a specialized four-bar linkage to achieve three adaptive grasping modes: parallel pinching, asymmetric scooping, and enveloping grasping. Hockens-A Hand requires only a single linear actuator, leveraging passive mechanical intelligence to ensure adaptability and compliance in unstructured environments. Specifically, the vertical motion of the Hoeckens mechanism introduces compliance, the double-parallelogram linkage ensures line contact at the fingertip, and the four-bar amplification system enables natural transitions between different grasping modes. Additionally, the inclusion of a mesh-textured silicone phalanx further enhances the ability to envelop objects of various shapes and sizes. This study employs detailed kinematic analysis to optimize the push angle and design the linkage lengths for optimal performance. Simulations validated the design by analyzing the fingertip motion and ensuring smooth transitions between grasping modes. Furthermore, the grasping force was analyzed using power equations to enhance the understanding of the system’s performance. Experimental validation using a 3D-printed prototype demonstrates the three grasping modes of the hand in various scenarios under environmental constraints, verifying its grasping stability and broad applicability.

This paper presents the SPARK finger, an innovative passive adaptive robotic finger capable of executing both parallel pinching and scooping grasps. The SPARK finger incorporates a multi-link mechanism with Kempe linkages to achieve a vertical linear fingertip trajectory. Furthermore, a parallelogram linkage ensures the fingertip maintains a fixed orientation relative to the base, facilitating precise and stable manipulation. By integrating these mechanisms with elastic elements, the design enables effective interaction with surfaces, such as tabletops, to handle challenging objects. The finger employs a passive switching mechanism that facilitates seamless transitions between pinching and scooping modes, adapting automatically to various object shapes and environmental constraints without additional actuators. To demonstrate its versatility, the SPARK Hand, equipped with two SPARK fingers, has been developed. This system exhibits enhanced grasping performance and stability for objects of diverse sizes and shapes, particularly thin and flat objects that are traditionally challenging for conventional grippers. Experimental results validate the effectiveness of the SPARK design, highlighting its potential for robotic manipulation in constrained and dynamic environments.

Current robot hand grippers capable of self-adaptive or coupled grasping often cannot perform linear-parallel pinching at the physical end of the gripper, which is widely used in industrial applications. For this reason, this paper introduces a gripper with hybrid grasping modes— the LPCSA hand. It can achieve three grasping modes: linear-parallel pinching, coupled, and self-adaptive grasping. The design cleverly couples two kinds of Chebyshev linear mechanisms to enable flat movement at the end of the finger. It also utilizes the deformability of the parallelogram to achieve self-adaptive grasping. Furthermore, the gripper uses an idle stroke and a special component to facilitate the switch between the three modes. The linear-parallel pinching function is suitable for pinching objects of different sizes on the desktop. The self-adaptive grasping mode can adapt to objects of various shapes and sizes. The coupled grasping mode enables fast grasping of irregular objects. This paper also analyzes the kinematics and dynamics of the LPCSA hand. Combined with experiments, it demonstrates that the LPCSA hand has a wide range of grasping space and stable performance.

Doffing robot is an important part of the spinning process in the textile production. This paper analyzes the doffing process of spinning machines and points out the requirements of the structure and functions of the doffer. The locking two-finger gripper, the three-dimensional circulating operation mechanism, the collaborating locating mechanism with the toothed disc and the pre-loosening mechanism by rotating spindles are designed. On this basis the continuous vertical-pulling automatic doffing robot, named CVP doffing robot, for the ring spinning is developed. The kinematics and dynamics analysis of the CVP doffing robot are carried out. The structural parameters of the CVP doffing robot are optimized by establishing kinematics and dynamics models. The forces of pulling out cops before and after the pre-loosing operation are tested. On this basis, the strength of the key components is designed and checked. Finally, the performance of the CVP doffing robot is verified by the doffing experiment.

This paper proposed a design idea of a novel under-actuated finger mechanism, and designed the finger mechanism. The finger has no actuator in itself, is only driven by the other finger joints and object grasped. The finger is similar to a human finger and can be easily arranged in series to realize a finger with super under-actuation and high integration. It can be mounted in humanoid robot hand to make the hand obtain more DOFs with less actuators, and good grasping function of shape adaptation, decrease the requirement of control system. This paper analyzed the relationship between the grasping force of the finger and its design parameters, proposed the design principle of structure optimization of the finger. Based on the finger, a multi-fingered humanoid robot hand: TH-2 Hand has been designed. TH-2 Hand has many excellent features: high personification, super under-actuation and be very compact, easy to real-time control, small volume, light in weight, strong grasping function, etc.

Conventional dexterous hands have too many DOFs, their driver systems are too big to be installed in a humanoid robot arm, and their controls are tool complex. This paper develops an under-actuated passive adaptive grasp humanoid robot hand named TH-1 hand with control of grasping force. With humanoid appearance and size, TH-1 hand is light, fewer DOFs, and can be easily controlled. Its motors and driver circuit boards are embedded in itself. These features make it fit to be installed in a humanoid robot arm. In addition, for stably grasping operation, a mechanical finger with control of grasping force is designed and applied in TH-1 hand's index. To get more DOFs with fewer drivers, a novel under-actuated passive adaptive grasp mechanical finger is design and applied in TH-1 hand's thumb.