This paper presents the design of hydraulically actuated quadruped robot HyQ2Max. HyQ2Max is an evolution 80 kg agile and versatile HyQ. Compared to HyQ, new needs be more rugged, powerful extend existing locomotion skills with self-righting capability. Since robot's actuation system has impact on many aspects overall design/specifications (e.g., payload, speed, torque, mass, compactness), this will pay special attention selection sizing joint actuators. To obtain meaningful requirements for...

We propose a reactive controller framework for robust quadrupedal locomotion, designed to cope with terrain irregularities, trajectory tracking errors and poor state estimation. The comprises two main modules: One related the generation of elliptic trajectories feet other control stability whole robot. task space CPG-based that can be modulated according irregularities posture robot trunk. To improve robot's stability, we implemented null based attitude trunk push recovery algorithm on...

Robots with legs and arms have the potential to support humans in dangerous, dull or dirty tasks. A major motivation behind research on such robots is their versatility. However, these come at a high price mechanical control complexity. Hence, until they can demonstrate clear advantage over simpler counterparts, will not fulfill true potential. In this paper, we discuss opportunities for versatile that arise by actively controlling impedance of joints particularly legs. contrast passive...

Reliable state estimation is crucial for stable planning and control of legged locomotion. A fundamental component a estimator in platforms Leg Odometry, which only requires information about kinematics contacts. Many robots use dedicated sensors on each foot to detect ground However, this choice impractical many agile field operations, as these often degrade break. Instead, paper focuses the development robust Odometry module, does not require contact sensors. The module estimates...

Legged robots can outperform wheeled machines for most navigation tasks across unknown and rough terrains. For such tasks, visual feedback is a fundamental asset to provide with terrain-awareness. However, robust dynamic locomotion on difficult terrains real-time performance guarantees remains challenge. We present here real-time, foothold adaptation strategy based feedback. Our method adjusts the landing position of feet in fully reactive manner, using only on-board computers sensors. The...

In this paper we present a system for the state estimation of dynamically walking and trotting quadruped.The approach fuses four heterogeneous sensor sources (inertial, kinematic, stereo vision LIDAR) to maintain an accurate consistent estimate robot's base link velocity position in presence disturbances such as slips missteps.We demonstrate performance our system, which is robust changes structure lighting environment, well terrain over robot crosses.Our builds upon modular inertial-driven...

Hydraulic actuation is the most widely used alternative to electric motors for legged robots and manipulators. It often selected its high power density, robustness high-bandwidth control performance that allows implementation of force/impedance control. Force crucial are in contact with environment, since it enables active impedance whole body can lead a better known unknown environments. This paper presents hydraulic Integrated Smart Actuator (ISA) developed by Moog collaboration IIT, as...

We present a novel control strategy for dynamic legged locomotion in complex scenarios that considers information about the morphology of terrain contexts when only on-board mapping and computation are available. The is built on top two main elements: first contact sequence task provides safe foothold locations based convolutional neural network to perform fast continuous evaluation search locations; then model predictive controller given by optimize target ground reaction forces. assess...

Whole-Body Control (WBC) has emerged as an important framework in locomotion control for legged robots. However, most WBC frameworks fail to generalize beyond rigid terrains. Legged over soft terrain is difficult due the presence of unmodeled contact dynamics that WBCs do not account for. This introduces uncertainty and affects stability performance system. In this article, we propose a novel adaptation algorithm called STANCE: Soft Terrain Adaptation Compliance Estimation. STANCE consists...

This paper presents a framework developed to increase the autonomy and versatility of large (~75kg) hydraulically actuated quadrupedal robot. It combines onboard perception with two locomotion strategies, dynamic trot static crawl gait. way robot can perceive its environment arbitrate between behaviours according situation at hand. All computations are performed on-board carried out in separate computers, one handles high-level processes while other is concerned low-level hard real-time...

This paper presents the development of lightweight hydraulic quadruped robot MiniHyQ. To authors' best knowledge, MiniHyQ is lightest and smallest that has been built so far. a fully torque controlled robot. It reconfigurable leg configurations. wide joint range motion an onboard compact power pack. The almost same length as previous (HyQ [1], by our group), but its link segment lengths are 15% less in flex configuration, due to special isogram knee mechanism. Its weight only 35kg (24kg with...

In legged locomotion, the projection of robot's Center Mass (CoM) being inside convex hull contact points is a commonly accepted sufficient condition to achieve static balancing. However, some these configurations cannot be realized because joint-torques required sustain them would above their limits (actuation limits). this article, we rule out such and define feasible region, revisited support region that guarantees both global stability in sense tip-over slippage avoidance existence set...

Abstract Litter nowadays presents a significant threat to the equilibrium of many ecosystems. An example is sea, where litter coming from coasts and cities via gutters, streets, waterways, releases toxic chemicals microplastics during its decomposition. removal often carried out manually by humans, which inherently lowers amount waste that can be effectively collected environment. In this paper, we present novel quadruped robot prototype that, thanks natural mobility, able collect cigarette...

The ability of legged systems to traverse highly- constrained environments depends by and large on the performance their motion balance controllers. This paper presents a controller that excels in scenario most state- of-the-art controllers have not yet addressed: line walking, or walking nearly null support regions. Our approach uses low-dimensional virtual model (2-DoF) generate balancing actions through previously derived four- term transforms them robot kinematic mapping. capabilities...

To traverse complex scenarios reliably a legged robot needs to move its base aided by the ground reaction forces, which can only be generated legs that are momentarily in contact with ground. A proper selection of footholds is crucial for maintaining balance. In this paper, we propose foothold evaluation criterion considers transition feasibility both linear and angular dynamics overcome scenarios. We devise convex nonlinear formulations as direct extension [1] receding-horizon fashion grant...

This work is on vision-based planning strategies for legged robots that separate locomotion into foothold selection and pose adaptation.Current adaptation optimize the robot's body relative to given footholds.If these footholds are not reached, robot may end up in a state with no reachable safe footholds.Therefore, we present Vision-Based Terrain-Aware Locomotion (ViTAL) strategy consists of novel algorithms.ViTAL introduces different paradigm does footholds, but maximizes chances legs...

Legged robots have the potential to navigate in more challenging terrain than wheeled do. Unfortunately, their control is difficult because they deal with traditional mapping and path planning problems, as well foothold computation, leg trajectories posture order achieve successful navigation. Many parameters need be adjusted real time keep robot stable safe while it moving. In this paper, we will present a new framework for quadruped robot, which performs goal-oriented navigation on unknown...