16 accepted papers
This paper presents a novel shared autonomy and baseline policy adapting framework for human-robot interactions in high-level context-aware robotic tasks. With a unique methodology that leverages hierarchies in decision-making as well as variational analysis of human policy, we propose a mathematica…
Forestry machines are not easily accessible for experimentation or demonstration of research results. These mobile robots are massive, very expensive, and require a large outdoor space and permits to operate. These factors hinder conducting experiments on real forestry robots. Thus, it is essential
The timber-harvesting industry is lagging its peer industries, such as mining and agriculture, with respect to deployment of robotic, AI and autonomous technologies. In this paper, we tackle automation of a critical task that arises in transporting logs from the forest to the sawmill: the log loadin…
Log loading constitutes a key operation in timber harvesting, and despite the recent spike of interest in introducing automation to the forestry sector, efficient and intelligent grasping of logs remains unresolved. This paper presents a grasp planning pipeline that relies on the identification of l…
When a robot end-effector is attached to the arm via passive joints, undesirable end-effector sway will occur. In a forestry crane, such as the log-loading or harvesting machine, this sway is problematic as it hinders the efficiency and also can harm the machine and environment. Here, we tackle the…
We examine the problem of agile trajectory tracking for a quadrotor vehicle with bidirectional thrust capabilities. A time-dependent linearization of the dynamics is presented based on the Lie algebra of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/19
Operating an articulated machine is a complex and hierarchical task, involving several levels of decision making. Motivated by the timber-harvesting applications of these machines, we are interested in developing a collaborative framework for operating an articulated machine/robot in order to increa…
This paper presents a path planning refinement technique that allows the efficient collision and rollover-free motion planning for mobile manipulator robots working on rough terrain. First, the necessary theoretical background on a mobile manipulator's kinematics and dynamic stability measure is int…
We present two novel nonlinear MPC formulations for reduced attitude tracking on quadrotors with bidirectional thrust capabilities. Reduced attitude tracking is relevant to recovery from partial thrust loss, which can occur due to the failure of one or more motors. The first formulation builds on a…
We consider the problem of collaborative transport of a payload using several quadrotor vehicles. The payload is assumed to be a rigid body and is attached to the vehicles with rigid rods. The model of the system is presented and is employed to formulate a Model Predictive Controller. The centralize…
Utilization of latent space to capture a lower-dimensional representation of a complex dynamics model is explored in this work. The targeted application is of a robotic manipulator executing a complex environment interaction task, in particular, cutting a wooden object. We train two flavours of Vari…
This paper presents a dynamic stability-constrained optimal motion planning algorithm developed for a timber harvesting machine working on rough terrain. First, the kinematics model of the machine, and the Zero Moment Point (ZMP) stability measure is presented. Then, an approach to simplify the mode…
Motivated by the recursive Newton-Euler formulation, we propose a novel cascaded Gaussian process learning framework for the inverse dynamics of robot manipulators. This approach leads to a significant dimensionality reduction which in turn results in better learning and data efficiency. We explore…
Small quadrotor UAVs are projected to fly increasingly in urban environments for a wide variety of applications such as disaster response, police surveillance, civil infrastructure inspection, and air quality measurement. Micro UAVs can detect and avoid obstacles using onboard cameras; nevertheless,…
Collisions between quadrotor UAVs and the environment often occur, for instance, under faulty piloting, from wind gusts, or when obstacle avoidance fails. Airspace regulations are forcing drone companies to build safer drones; many quadrotor drones now incorporate propeller protection. However, prop…
This paper presents an account of the experimentations with a ground-based facility emulating interception scenarios with non-cooperative space debris using a robotic manipulator. A sampling-based motion-planning algorithm is used to autonomously solve the dynamic interception problem without collis…