upper/lower-arm coordinated motion planning and synchronization

Designs and implements motion planners and synchronization controllers that generate coordinated trajectories and timing for multiple arm effectors or for coupled upper- and lower-arm segments, ensuring tasks are achieved while respecting kinematic and dynamic constraints, inter-limb coupling, and collision avoidance. Builds trajectory-generation, synchronization, and execution-monitoring components that integrate task-level goals with low-level control to produce smooth, feasible, and time-aligned coordinated arm motions.

upperlower-armcoordinatedmotion

Recent Skill Trend

Momentum and market value over time
Trending
Score
No comparison yet
0.59
Oct 01, 2026Oct 01, 2026
Career
Value
No comparison yet
$200K/year
Oct 01, 2026Oct 01, 2026

Must-Read Papers

Most classic and influential ideas
View more

This study addresses the lack of a unified and portable real-time low-level motion planning interface for heterogeneous collaborative robotic arms. To bridge this gap, the authors propose a lightweight and flexible real-time end-effector trajectory control interface built upon the WinGs Operating Studio middleware. The approach integrates n-th-order polynomial interpolation with a quadratic programming (QP) solver to generate smooth, continuously differentiable trajectories that enable precise control over position, velocity, and acceleration. For the first time, real-time low-level motion planning across multiple brands of collaborative arms is achieved under a single interface, featuring on-the-fly replanning capability and cross-platform compatibility. Experimental validation through offline drawing, dynamic grasping, and cross-arm teleoperation demonstrates significant improvements in system generality, deployment efficiency, and usability.

collaborative robotshardware portabilitylow-level control

Safe Task Space Synchronization with Time-Delayed Information

Sep 26, 2025
RB
Rounak Bhattacharya
🏛️ University of Connecticut

This paper addresses the challenge of human–robot collaboration under communication delays in human trajectory information and complete uncertainty in the robot’s kinematic and dynamic models. Method: We propose a task-space adaptive synchronization controller that, for the first time, integrates Barrier Lyapunov Functions (BLFs) with Lyapunov–Krasovskii functionals to construct a delay-compensation mechanism. Unknown model parameters are jointly estimated online via two complementary adaptive laws: one based on iterative composite learning (ICL) and the other on gradient descent—ensuring real-time synchronization while respecting safety constraints. Contribution/Results: The closed-loop error system is proven semi-globally uniformly ultimately bounded (SGUUB). Simulation results demonstrate high-precision tracking of delayed human trajectories under typical communication delays, while rigorously satisfying state constraints and collaborative safety requirements.

Ensuring safety during human-robot collaboration tasksHandling unknown robot kinematics and dynamics parametersSynchronizing robot trajectory with delayed human motion

An Optimization-Augmented Control Framework for Single and Coordinated Multi-Arm Robotic Manipulation

Jun 19, 2025
MO
Melih Ozcan
🏛️ Middle East Technical University | Bilkent University

Addressing challenges in single- and multi-arm cooperative manipulation—including strong force-motion coupling, seamless switching between free motion and contact interaction over long time horizons, and lack of joint object-environment constraint modeling for inter-arm synchronization—this paper proposes a dynamically switchable three-modal control framework: pure planning, pure force control, and hybrid coordination. We introduce, for the first time, a task-driven dynamic modality allocation mechanism and systematically support joint object-environment constraint modeling in multi-arm settings. The method integrates impedance/admittance-based force control, nonlinear optimization-based motion planning (SQP/OC), real-time mode scheduling, and multibody dynamics modeling. Evaluated on long-horizon tasks—including single-arm assembly, dual-arm flipping, and tri-arm transport—the approach achieves a 42% reduction in contact force error, a 35% improvement in trajectory tracking accuracy, and a 98.7% task success rate.

Combining force control and motion planning for robotic manipulationEnabling seamless switching between control modes for complex tasksImproving multi-arm coordination in dynamic and contact-rich environments

NMPC-based Motion Planning with Adaptive Weighting for Dynamic Object Interception

Nov 19, 2025
CC
Chen Cai
🏛️ University of Kaiserslautern-Landau

Addressing the challenges of coordination and poor real-time performance in dual-arm collaborative robots intercepting high-speed dynamic objects under closed-chain constraints, this paper proposes an adaptive terminal nonlinear model predictive control (NMPC) framework. The method integrates cost shaping with real-time joint-space motion planning to tightly couple dynamic trajectory generation and closed-loop control—thereby simultaneously ensuring motion agility, significantly reducing control energy consumption, and enhancing robustness. Experimental results demonstrate an average planning cycle of only 19 ms—less than half the system’s sampling period—enabling millisecond-level response and high-precision dynamic interception. The proposed approach is validated to achieve superior computational efficiency, motion quality, and constraint satisfaction.

Addresses actuator power limit violations through adaptive cost shaping formulationDevelops NMPC motion planner for cooperative robotic arms intercepting dynamic objectsEnables real-time performance with 19ms computation for dynamic interception tasks

DAG-Plan: Generating Directed Acyclic Dependency Graphs for Dual-Arm Cooperative Planning

Jun 14, 2024
ZG
Zeyu Gao
🏛️ Chinese Academy of Sciences | University of Chinese Academy of Sciences | The University of Hong Kong | Shanghai AI Laboratory

Long-horizon collaborative tasks for dual robotic arms face challenges including complex spatiotemporal dependencies among subtasks, difficulty in dynamic action allocation, and limited expressiveness of linear programming formulations. This paper proposes the first LLM-driven DAG-structured task decomposition framework, which automatically parses high-level instructions into directed acyclic graphs (DAGs) encoding dependency constraints, and integrates environment perception to enable real-time, dynamic action allocation and parallel adaptive execution across both arms. The method breaks away from predefined operational paradigms, supporting end-to-end, interpretable, and generalizable collaborative planning. Evaluated on the Dual-Arm Kitchen benchmark, it achieves a 52.8% efficiency gain over single-arm systems, improves success rate by 48% and reduces LLM query count by 84.1% compared to conventional dual-arm planners, significantly enhancing robustness and scalability in complex scenarios.

Coordinating dual-arm robots for complex long-horizon tasksManaging temporal and spatial dependencies between sub-tasksOptimizing action allocation and execution order for dual arms

Latest Papers

What's happening recently
View more

This work addresses the challenges of deploying learned multi-hand manipulation policies on multi-arm robotic systems, which involve trajectory assignment, kinematic constraints, and collision avoidance. The authors propose a unified conflict-based search framework that jointly models the discrete assignment of trajectories to arms and continuous motion planning within the nullspace of redundant-arm Jacobians—an integration not previously achieved. By doing so, the method ensures precise end-effector tracking of policy-specified trajectories while respecting kinematic limits and avoiding collisions, thereby overcoming the safety and feasibility limitations inherent in conventional single-arm inverse kinematics extensions. Experimental results demonstrate that the approach enables efficient and reliable embodiment of multi-hand policies on real multi-arm platforms, exhibiting both theoretical soundness and practical effectiveness.

collision avoidanceinverse kinematicsmulti-arm manipulation

This work addresses the “execution gap” between high-level semantic tasks and executable robot motions by introducing Motion Statecharts—a symbolic, executable motion representation that supports concurrency and hierarchical nesting. Coupled with a unified differentiable kinematic world model, this framework enables end-to-end mapping from semantic task specifications to low-level motion control. Smooth and dynamically feasible trajectories are generated through a linear model predictive control (lMPC)-driven task-function approach incorporating snap (jerk derivative) constraints. The proposed system has been successfully deployed across eight heterogeneous robotic platforms, demonstrating strong cross-platform generalization and real-world efficacy. The accompanying software framework, Giskard, has been publicly released.

Kinematic ControlMotion Execution GapRobot Motion Planning

This work addresses the limitations of classical trajectory planning methods, which prioritize kinematic smoothness while neglecting dynamics and actuator control effort, often resulting in large tracking errors and high energy consumption. To overcome these issues, the authors propose a control-aware optimal trajectory planning framework that explicitly integrates the nonlinear dynamics of robotic manipulators and actuator effort over a finite time horizon. A midpoint linearization strategy is introduced to enhance the accuracy of dynamic approximations during large-range motions. By establishing a unified nonlinear closed-loop simulation environment, the study enables, for the first time, an isolated evaluation of trajectory generation methods under identical conditions. Experimental results on a simplified UR5 model demonstrate that the proposed approach significantly reduces tracking error, corrective torque, and overall closed-loop execution cost, achieving substantially lower energy consumption and total operational expense compared to conventional planners such as cubic, quintic, and trapezoidal profiles.

actuator effortcontrol-awaredynamic efficiency

This work addresses the challenge of real-time motion planning for complex robotic systems under geometric constraints, which is often hindered by high computational costs. For the first time, SIMD parallelization is introduced into manifold-constrained motion planning by reformulating projection operations into a parallelizable structure that leverages CPU SIMD instruction sets to efficiently accelerate constraint satisfaction. The proposed method dramatically improves computational efficiency, enabling real-time whole-body quasi-static motion planning on a physical humanoid robot. Experimental results demonstrate speedups of 100 to 1,000 times compared to existing approaches, while maintaining accuracy and feasibility under stringent geometric constraints.

computational efficiencyconstraint satisfactionhumanoid robots

Hot Scholars

MH

Marco Hutter

Professor of Robotics, ETH Zurich
Legged RoboticsRoboticsControl
YL

Yibin Liu

Northeastern University
NLPRoboticsHCI
WS

Wei-Shi Zheng

Professor @ SUN YAT-SEN UNIVERSITY
Computer VisionPattern RecognitionMachine Learning
MT

Masayoshi Tomizuka

Mechaniccal Engineering, University of California
mechanical engineeringdynamic systemscontrolmechatronics
AC

Andrei Cramariuc

Postdoctoral Researcher, ETH Zürich
RoboticsMachine Learning