26 accepted papers
Diffusion models offer powerful generative capabilities for robot trajectory planning, yet their practical deployment on robots is hindered by a critical bottleneck: reliance on imitation learning from expert demonstrations. This paradigm is often impractical for specialized robots where data is sca…
Accurate, large-scale Martian segmentation datasets are a cornerstone of autonomous scene understanding in support of exploration and navigation in Martian environments. However, high-quality segmentation labeling on planetary images requires annotators to have professional extraterrestrial geologic
This paper proposes a method to estimate the wheel slip ratio and side slip angle of wheeled rovers by processing images of wheel trace imprints. The proposed method extracts structural features from trace imprint images, such as the trace unit, trace contour, and angle between the centerline of the
Deep reinforcement learning (DRL) methods have shown significant promise in controlling the movement of quadruped robots. However, for systems like hexapod robots, which feature a higher-dimensional action space, it remains challenging for an agent to devise an effective control strategy directly. C
The increasingly complex and diverse planetary exploration environment requires more adaptable and flexible rover navigation strategy. In this study, we propose a VLM-empowered multi-mode system to achieve efficient while safe autonomous navigation for planetary rovers. Vision-Language Model (VLM) i
Reinforcement learning (RL) has demonstrated impressive performance in legged locomotion over various challenging environments. However, due to the sim-to-real gap and lack of explainability, unconstrained RL policies deployed in the real world still suffer from inevitable safety issues, such as joi
Specialized robots, such as legged robots and unmanned aerial vehicles (UAVs), are commonly regarded as effective platforms for aiding in search and rescue (SAR) missions. However, existing approaches often decouple the tasks between UAVs and legged robots, for instance, using UAVs for mapping and l
Traditional skid or wheeled landing gears fall short in meeting the rigorous requirements of challenging surfaces such as rugged terrain and swaying deck, which restraints the application in extreme tasks including disaster rescue, cargo transportation as well as ship-relevant operations. This paper
Developing gaits inspired by animal locomotion for quadruped robots has become a prevalent approach in achieving dynamic locomotion. Analogous to animal gaits, they exhibit optimal effectiveness at specific velocities, necessitating the transitions between them for enhanced locomotion proficiency. D
This letter investigates initial-pose estimation (Cartesian position and orientation) for redundant cable-driven parallel robots (CDPRs). As the forward kinematics cannot be performed if the robot is equipped with incremental sensors, a calibration method using force sensors is proposed. The self-ca
Autonomous navigation plays an increasingly crucial role in rover-based planetary missions. End-to-end navigation approaches developed upon deep reinforcement learning have enabled great adaptability in complex environments. However, most existing works focus on geometric obstacle avoidance thus hav
Planetary rovers with lugged-wheels are the primary equipment for Mars exploration, and as exploration missions become more complex, rovers are expected move into more challenging terrains. When moving over soft sand or slopes, lugged-wheels experience high slip and heavy sinkage, and an explicit si
Legged robots can pass through complex field environments by selecting gaits and discrete footholds carefully. Conventional methods plan gaits and footholds separately and treat them as a single-step optimal process. However, such approaches cause poor passability in sparse foothold environments. Th
Non-geometric hazards like sinkage and slipping, correlated to terrain categories, have an apparent effect on the locomotion of legged robots. Tactile-based terrain classification is a more accurate way to distinguish terrains in different properties than the vision, but selecting representative fea
Human-robot collaboration (HRC) significantly extends robotic systems’ applications when working in spaces like houses, hospitals, or laboratories. However, new challenges appear during a close collaboration between humans and robots and imitating the movement of humans by robots. Learning from demo…
Drawbar pull and driving torque are usually applied to characterize the mobility and energy consumption, respectively, of wheeled planetary rovers (WPRs) traversing sandy terrain. Owing to the complexity of the grouser-terrain interaction, neither can be modeled as a closed-form analytical expressio
The slippage appears on soft terrains for wheeled mobile robots (WMR), and generates a motion deviation at the contact area, which can induce poor command-tracking performance (meaning difference between WMR's actual motion and operator's command) and instability for its teleoperation. Our previous
With the increasing applications of wheeled mobile manipulators (WMMs), new challenges have arisen in terms of executing high-force tasks while maintaining precise trajectory tracking. A WMM, which consists of a manipulator mounted on a mobile base, is often a kinematically redundant robot. The exis
This paper presents a trajectory optimization formulation for planning dynamic trajectories of a six-degree-of-freedom (six-DOF) cable-suspended parallel robot (CSPR) that extend beyond the static workspace. The optimization is guided by low-dimensional dynamic models to overcome the local minima an…
Compared with conventional robots, soft structures such as living octopus arms and various soft-robot arms have more degrees of freedom (DOFs) and greater flexibility. Soft robot arms have a considerable range of applications. However, it is arduous to establish a mechanical model for them, because…
In an autonomous scientific exploration system, the terrain map generated from mapping process integrates sensing information from multiple aspects and lays the base for decision making processes. With the increasing challenges in planetary exploration, equipping planetary rovers with the principles…
The Spring-Loaded Inverted Pendulum (SLIP) has been widely exploited in both biomechanical and robotics research due to its simple form in mathematics and high accuracy in fitting experimental biology data. However the intrinsic nonlinearity of the SLIP dynamics makes accurate analytical representat…
Simulation of planetary rovers moving on complex terrains is critical for Mars exploration. Equivalent stiffness is proposed and used to characterize the pressure-sinkage property of terrain, while friction angle to characterize the shearing property. Terramechanics model for calculating forces betw…
Biologically inspired by the hopping performance of kangaroo, this paper extends the traditional Spring-loaded Inverted Pendulum (SLIP) model by adding an actuation at hip to composite a tail-actuated SLIP (TSLIP) model as an abstract template for gait controller design. To deal with the intrinsic n…
With the widespread use of wheeled mobile robots (WMR) in various applications, new challenges have emerged in terms of designing its teleoperation system. One of such challenges is caused by wheel slippage and another is due to the strict need for ensuring WMR safety. This letter proposes a new tri