34 accepted papers
Task and Motion Planning (TAMP) frameworks for bimanual robots are limited by the combinatorial explosion at the task planning level, which can negatively affect human-robot interaction. This work introduces BAG-Learn Planning, an efficient learning-based task planning approach that combines a Bio-I…
Path planning is fundamental for controlling orthopedic robots and vital in ensuring surgical safety. To address the problem of low path-planning efficiency in traditional path planning methods, this work proposes an improved APF-RRT* algorithm for efficient path planning of fracture reduction. Firs
Teaching and learning physical skills often require one-on-one interaction, making it difficult to scale up, as there are not enough human teachers. Robots offer an attractive alternative. This paper presents <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/
Teaching and learning physical skills often require one-on-one interaction, making it difficult to scale up, as there are not enough human teachers. Robots offer an attractive alternative. This paper presents TeachingBot, an adaptive robotic system that teaches handwriting to human learners through …
Impedance-based control represents a prevalent strategy in the powered transfemoral prostheses because of its ability to reproduce natural walking. However, most existing studies have developed impedance-based prosthesis controllers for specific tasks, while creating a task-adaptive controller for v
This paper proposes a new variable gain sliding mode filter augmented by variable windowing for achieving smooth and reactive response over a broad range of input frequencies. The proposed filter can be seen as a synergistic combination of Kikuuwe et al.'s [1] sliding mode filter with varying gain a
Knee angle estimation plays a crucial role in the development of lower limb assistive devices, particularly prostheses. Current research in this area primarily focuses on stable gait movements, which limits applicability to real-world scenarios where human motion is far more complex. In this paper,
Ensuring safety is crucial to promote the application of robot manipulators in open workspaces. Factors such as sensor errors or unpredictable collisions make the environment full of uncertainties. In this work, we investigate these potential safety challenges on redundant robot manipulators, and pr
This paper proposes a task-oriented model predictive control (ToMPC) framework for safe and efficient robotic manipulation in open workspaces. The framework unifies collision-free motion and robot-environment interaction to address diverse scenarios. Additionally, it introduces task-oriented obstacl
Body weight support (BWS) systems are extensively utilized in rehabilitation robots to deliver sophisticated unloading force (i.e., vertical interaction force) for gravity and impedance compensation. The robust and accurate unloading force rendering is critical for gait training. In this letter, a c
Parameter convergence in adaptive control is crucial for improving the stability and robustness of robotic systems. Nevertheless, a stringent condition named persistent excitation (PE) needs to be satisfied to ensure parameter convergence in the conventional adaptive robot control. Composite learnin…
To achieve high-accuracy manipulation in the presence of unknown disturbances, we propose two novel efficient and robust motion control schemes for high-dimensional robot manipulators. Both controllers incorporate an unknown system dynamics estimator (USDE) to estimate disturbances without requiring…
The human sense of touch enables us to perform delicate tasks on deformable objects and/or in a vision-denied environment. To achieve similar desirable interactions for robots, such as administering a swab test, tactile information sensed beyond the tool-in-hand is crucial for contact state estimati
Researchers are currently making progress in unifying the entire gait cycle of powered prostheses by using a human-inspired phase variable, but constructing a robust phase variable to more accurately estimate the gait phase and desired joint trajectories of prostheses during varying walking speeds r
Firstly, in the letter [1], there is a missing citation in Section II, part B, the first sentence. It should be “In a manner similar to [2], [3], speed estimation was achieved by a double-pendulum model.” In our previous version [1], speed estimation was based on the principles in [3]. We also refer
Most human activities in daily living or professional work rely on upper body motion. Measuring upper body motion is essential for many applications such as health evaluation, rehabilitation, human power augmentation, skill transferring, etc. Computer vision-based systems have been widely used to di…
Soft robotic grippers have attracted considerable attention in terms of the advantages of the high compliance and robustness to variance in object geometry; however, they are still limited by the corresponding sensing capabilities. We propose a novel soft gripper that looks like a ‘granary’ in the g
Humans can use different grasping poses and forces for everyday objects of different shapes and sizes. Grasping and manipulating everyday objects have been longstanding challenges in robotics. Performing multiple grasping configurations is difficult for robotic end-effectors with limited degrees of
In recent years, lower-limb exoskeletons have been applied to assist people with weak mobility in daily life, which requires enhanced adaptability to complex environments. To achieve a smooth transition between different assistive strategies and provide proper assistance at the desired timing during
Gait rehabilitation is essential for chronic stroke patients to regain independent walking ability and quality of life, of which symmetry is regarded as a gold standard of gait quality. In this letter, a cable-driven lower limb exoskeleton powered by series elastic actuators (SEAs) has been develope
Motion control of multi-joint Series Elastic Actuator (SEA)-driven robots still faces challenges including intrinsic oscillatory dynamics, high-order robotic dynamics, low-bandwidth inner loop, and dynamic nonlinearities. In this letter, a nonlinear disturbance observer (NDOB)-based robust controlle…
To function effectively in real-world environments, powered wearable robots such as exoskeletons and robotic prostheses must recognize the user's motion intent by detecting the user's locomotion modes such as walking, stair ascent and descent or ramp ascent and descent. Traditionally, intent detecti…
Soft robot has demonstrated promise in unstructured and dynamic environments due to unique advantages, such as safe interaction, adaptiveness, easy to actuate, and easy fabrication. However, the highly dissipative nature of elastic materials results in small stiffness of soft robot which limits cert…
We present a differential-algebraic formulation with switching constraints to model the nonsmooth dynamics of robotic systems subject to changing constraints and multiple impacts. The formulation combines a single structurally simple governing equation, a set of switching kinematic constraints, and…
How to build a biomimetic robot fish has always been a divergent question. Most of the existing robot fishes suffer structural complexity and propulsive inefficiency. In this paper, we proposed a method that transfers the natural actuation properties of fish to the biomimetic robot counterpart. The
A Series Elastic Actuator (SEA) is designed by placing a passive compliant element between a conventional stiff actuator and link. The intrinsically compliant mechanical structure provides several superiorities, e.g., safety, energy efficiency, high force fidelity, low cost force measurement, high t…
In this paper, a new robust position controller is proposed for Series Elastic Actuators (SEAs) by using Sliding Mode Control (SMC) and a second order Disturbance Observer (DOb). The latter estimates not only disturbances but also their first and second order successive derivatives. A simple yet eff…
Brain-computer interface (BCI) systems can translate the human mind into control commands, which makes it feasible to improve the life quality of physically challenged people. However, in real-life situations, it is still difficult for users to utilize robots to provide basic services with BCI syste…
Brain-Machine Interface (BMI) has emerged as a powerful tool for assisting disabled people and for augmenting human performance. Up so far, no studies have succeeded in the power augmentation for the multi-DOFs robot based on EEG signals, especially for the complex shoulder joint. In this work, we p…
Series Elastic Actuators (SEAs) have several superiorities over conventional stiff and non-back-drivable actuators in force control, e.g., lower reflected inertia, low cost force measurement, high force fidelity, safety, and so on. However, their position control applications significantly suffer fr…
Series elastic actuators (SEAs) are known to offer a number of advantages such as high force/torque fidelity, low impedance, and tolerance to shocks, which make it suitable for the applications involving human-robot interaction. In existing SEA-driven robot systems, the control objective is usually
In this paper, a novel constrained tendon-driven serpentine manipulator (CTSM) suited for minimally invasive surgery is presented. It comprises of a flexible backbone, a set of controlling tendons and a constraint. In the CTSM not only the curvature of the bending section can be controlled but also…
Series elastic actuator (SEA) has been widely used in rehabilitation robotics, where human-robot interaction is required. Due to its intrinsic compliance, SEA can improve the usage of power for its motor, which leads to a compact and lightweight SEA design. The aim of this paper is to reduce the ene…
This paper proposes a new robust position control method for a novel series elastic actuator (SEA). It is a wellknown fact that SEAs provide many benefits in force control, e.g., lower reflected inertia and impedance, greater shock tolerance, safety, and so on. However, current SEA designs have a co…