Robot Task-Constrained Optimization and Adaptation with Probabilistic Movement Primitives.

Enabling a robot to learn skills from a human and adapt to different task scenarios will enable the use of robots in manufacturing to improve efficiency. Movement Primitives (MPs) are prominent tools for encoding skills. This paper investigates how to learn MPs from a small number of human demonstrations and adapt to different task constraints, including waypoints, joint limits, virtual walls, and obstacles.

Screening of the Candidate Metabolite to Evaluate the Mycelium Physiological Maturation of Based on Metabolome and Transcriptome Analysis.

is a commercially cultivated rare edible mushroom with high dietary and medicinal value. The mycelium physiological maturation was an important factor to the yield and quality of mushrooms obtained. However, it was impossible to obtain discriminative characteristics represented the maturity level of the mycelia from morphological features.

Bipedal Stepping Controller Design Considering Model Uncertainty: A Data-Driven Perspective.

This article introduces a novel perspective on designing a stepping controller for bipedal robots. Typically, designing a state-feedback controller to stabilize a bipedal robot to a periodic orbit of step-to-step (S2S) dynamics based on a reduced-order model (ROM) can achieve stable walking. However, the model discrepancies between the ROM and the full-order dynamic system are often ignored.

A Distortion Correction Method Based on Actual Camera Imaging Principles.

In the human-robot collaboration system, the high-precision distortion correction of the camera as an important sensor is a crucial prerequisite for accomplishing the task. The traditional correction process is to calculate the lens distortion with the camera model parameters or separately from the camera model. However, in the optimization process calculate with the camera model parameters, the mutual compensation between the parameters may lead to numerical instability, and the existing distortion correction methods separated from the camera model are difficult to ensure the accuracy of the correction.

4-Coumarate-CoA ligase (4-CL) enhances flavonoid accumulation, lignin synthesis, and fruiting body formation in Ganoderma lucidum.

It is now understood that 4-Coumarate-CoA ligases (4-CL) are pivotal in bridging the phenylpropanoid metabolic pathway and the lignin biosynthesis pathway in plants. However, limited information on 4-CL genes and their functions in fungi is available. In this study, we cloned the 4-CL gene (Gl21040) from Ganoderma lucidum, which spans 2178 bp and consists of 10 exons and 9 introns.

Joint Calibration Method for Robot Measurement Systems.

Robot measurement systems with a binocular planar structured light camera (3D camera) installed on a robot end-effector are often used to measure workpieces' shapes and positions. However, the measurement accuracy is jointly influenced by the robot kinematics, camera-to-robot installation, and 3D camera measurement errors. Incomplete calibration of these errors can result in inaccurate measurements.

A Hierarchical Motion Planning Method for Mobile Manipulator.

This paper focuses on motion planning for mobile manipulators, which includes planning for both the mobile base and the manipulator. A hierarchical motion planner is proposed that allows the manipulator to change its configuration autonomously in real time as needed. The planner has two levels: global planning for the mobile base in two dimensions and local planning for both the mobile base and the manipulator in three dimensions.

Symmetrical Efficient Gait Planning Based on Constrained Direct Collocation.

Biped locomotion provides more mobility and effectiveness compared with other methods. Animals have evolved efficient walking patterns that are pursued by biped robot researchers. Current researchers have observed that symmetry is a critical criterion to achieve efficient natural walking and usually realize symmetrical gait patterns through morphological characteristics using simplified dynamic models or artificial priors of the center of mass (CoM).

A Non-Flat Terrain Biped Gait Planner Based on DIRCON.

Various constraints exist in bipedal movement. Due to the natural ability of effectively handling constraints, trajectory optimization has become one of the mainstream methods in biped gait planning, especially when constraints become much more complex on non-flat terrain. In this paper, we propose a multi-modal biped gait planner based on DIRCON, which can generate different gaits for multiple, non-flat terrains.

Transcriptome and metabolome analyses reveal transcription factors regulating ganoderic acid biosynthesis in development.

is an important medicinal fungus in Asian countries. Ganoderic acid (GA) is the major variety of bioactive and medicative components in . Biosynthesis of secondary metabolites is usually associated with cell differentiation and development.

Research on Theory and a Performance Analysis of an Innovative Rehabilitation Robot.

This paper presents an innovative application of a 6-DOF robot in the field of rehabilitation training. This robot operates in a parallel fashion for lower limb movement, which adopts a new structure that can help patients to carry out a variety of rehabilitation exercises. Traditional parallel robots, such as the Stewart robot, have the characteristics of strong bearing capacity.

A Task-Learning Strategy for Robotic Assembly Tasks from Human Demonstrations.

In manufacturing, traditional task pre-programming methods limit the efficiency of human-robot skill transfer. This paper proposes a novel task-learning strategy, enabling robots to learn skills from human demonstrations flexibly and generalize skills under new task situations. Specifically, we establish a markerless vision capture system to acquire continuous human hand movements and develop a threshold-based heuristic segmentation algorithm to segment the complete movements into different movement primitives (MPs) which encode human hand movements with task-oriented models.

Feature Sensing and Robotic Grasping of Objects with Uncertain Information: A Review.

As there come to be more applications of intelligent robots, their task object is becoming more varied. However, it is still a challenge for a robot to handle unfamiliar objects. We review the recent work on the feature sensing and robotic grasping of objects with uncertain information.

Analysis and control of biped robot with variable stiffness ankle joints.

Background: Biped robot locomotion is an active topic of research, and the walking stability is one of the research objectives.

Objective: This paper discusses the variable stiffness ankle joint and the walking control of a biped robot.

Methods: A design is introduced that achieves the ankle joint variable stiffness by using a pneumatic unit.

Robot complex motion learning based on unsupervised trajectory segmentation and movement primitives.

This paper presents a robot skill acquisition framework for learning and reproducing humanoid trajectories with complex forms. A new unsupervised segmentation method is proposed to detect motion units in the demonstrated kinematic data using the concept of key points. To find the consistent features of trajectories, a Hidden Semi-Markov Model (HSMM) is used to identify key points common to all the demonstrations.

Dynamic Parameter Identification for a Manipulator with Joint Torque Sensors Based on an Improved Experimental Design.

As the foundation of model control, robot dynamics is crucial. However, a robot is a complex multi-input-multi-output system. System noise seriously affects parameter identification results, thereby inevitably requiring us to conduct signal processing to extract useful signals from chaotic noise.

Gait Symmetry Can Reduce Dependence on the Intact Limb during Walking with Constraint of Unilateral Metatarsophalangeal Joints.

Our previous research showed that healthy subjects exhibited asymmetrical walking gait when their unilateral metatarsophalangeal (MTP) joints were constrained. They relied more on their intact limb for the compensation of missing functions of their constrained limb, which may result in poor balance, increased metabolic cost, and higher risks of falls. We examined how subjects would respond if gait asymmetry in stance time was improved using a split-belt treadmill.

Design and Evaluation of a Wearable Powered Foot Orthosis with Metatarsophalangeal Joint.

The metatarsophalangeal (MTP) joints play critical roles in human locomotion. Functional restriction or loss of MTP joints will lead to lower walking speed, poorer walking balance, and more consumed metabolic energy cost compared with normal walking. However, existing foot orthoses are focused on maintaining the movement of the ankle joint, without assisting the MTP joints.

A Force-Sensing System on Legs for Biomimetic Hexapod Robots Interacting with Unstructured Terrain.

The tiger beetle can maintain its stability by controlling the interaction force between its legs and an unstructured terrain while it runs. The biomimetic hexapod robot mimics a tiger beetle, and a comprehensive force sensing system combined with certain algorithms can provide force information that can help the robot understand the unstructured terrain that it interacts with. This study introduces a complicated leg force sensing system for a hexapod robot that is the same for all six legs.

Position control of a single pneumatic artificial muscle with hysteresis compensation based on modified Prandtl-Ishlinskii model.

Background: High-performance position control of pneumatic artificial muscles is limited by their inherent nonlinearity and hysteresis.

Objective: This study aims to model the length/pressure hysteresis of a single pneumatic artificial muscle and to realize its accurate position tracking control with forward hysteresis compensation.

Methods: The classical Prandtl-Ishlinskii model is widely used in hysteresis modelling and compensation.

Study of human walking patterns based on the parameter optimization of a passive dynamic walking robot.

Background: The study of human walking patterns mainly focuses on how control affects walking because control schemes are considered to be dominant in human walking.

Objective: This study proposes that not only fine control schemes but also optimized body segment parameters are responsible for humans' low-energy walking.

Methods: A passive dynamic walker provides the possibility of analyzing the effect of parameters on walking efficiency because of its ability to walk without any control.

Design and control of a pneumatic musculoskeletal biped robot.

Background: Pneumatic artificial muscles are quite promising actuators for humanoid robots owing to their similar characteristics with human muscles. Moreover, biologically inspired musculoskeletal systems are particularly important for humanoid robots to perform versatile dynamic tasks.

Objective: This study aims to develop a pneumatic musculoskeletal biped robot, and its controller, to realize human-like walking.

Design of a biped robot actuated by pneumatic artificial muscles.

High compliant legs are essential for the efficient versatile locomotion and shock absorbency of humans. This study proposes a biped robot actuated by pneumatic artificial muscles to mimic human locomotion. On the basis of the musculoskeletal architecture of human lower limbs, each leg of the biped robot is modeled as a system of three segments, namely, hip joint, knee joint, and ankle joint, and eleven muscles, including both monoarticular and biarticular muscles.