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This paper presents a method for the real-time determination of joint angles, velocities, accelerations and joint torques of a human. The proposed method is based on a constrained Extended Kalman Filter that combines stereophotogrammetric and dynamometric data. In addition to the joint variables, subject-specific segment lengths and inertial parameters are identified. Constraints are added to the...
The paper is focused on a detailed dynamic study for an axis belonging to a serial robot structure. It contains an analytical study for the driving moments for a translational robot axis based on ball screw transmission. The study of transmission gearing, and implicit a rigorous determination of the driving moments, along the cinematic chain of the mechanical robotic system is a fundamental aspect,...
The kernel of the system is an intelligent control algorithm which can recognize precisely the whole dropping-process from launch module starting up to the miniature robots touching down and then determine whether the robot lands finally. The controller will activate a motor to realize the separation of parachute from the landed robot. This article, based on research into the principle of the system,...
This paper proposes a novel control architecture for bilateral teleoperation with time delay. The proposed bilateral teleoperation system has transparency under the presence of time delay. The conventional bilateral teleoperation system cannot have transparency under time delay because the control goals are not clear and inappropriate in the presence of time delay. The proposed method utilizes the...
This paper presents a novel approach to generate online jerk-limited trajectories for multi-DOF robotic systems. Finite Impulse Response filters are used to efficiently turn low computational cost acceleration-limited profiles into jerk-limited profiles. Starting from a new setpoint, e.g. an event given by external sensors, and an arbitrary state of motion, i.e. with non-zero initial velocity and...
In various circumstances, planning at trajectory level is very useful to generate flexible collision-free motions for autonomous robots, especially when the system interacts with humans or human environment. This paper presents a simple and fast obstacle avoidance algorithm that operates at the trajectory level in real-time. The algorithm uses the Velocity Obstacle to obtain the boundary conditions...
this study aims to determine the factors that affect the electromyography signal amplitude of human muscles. In a previous study, it was determined that increases in movement velocity and acceleration led to an increase in EMG signal amplitude. In this study, EMG signal amplitudes were investigated under varying degree of muscle flexion while at rest, by varying the angle of initial positions. Eight...
Deformation of optimal trajectories has a great potential in various applications due to the ability of real-time recomputation of the overall trajectory when applying new boundary conditions. This paper presents a novel approach where optimal trajectories are created offline through numerical direct optimal control methods. Afterwards the trajectories are deformed online with a spline deformation...
We propose an algorithm for planning the velocity of a vehicle on a pre-planned path applicable to differentially steered, zero turn radius, mobile robots with symmetric mass distribution about the turn axis. This approach uses estimates of path curvature to maintain tracking precision in the vehicle's heading controller. The longitudinal speed of the vehicle is restricted to limit the bandwidth of...
Humanoid robots propel themselves and perform tasks by interacting with their environment through contact forces. Typically, nonuniqueness of these forces is dealt with by distributing them evenly between the contacts. In the present paper, we introduce strict prioritization in contact force distribution, to reflect situations when an application of certain contact forces should be avoided as much...
Quadrotors have become a commonly used research platform in aerial robotics for the last decade. With the ability of flying in three-dimensional space, quadrotors possess great academic potential in control theory, synchronous localization and mapping (SLAM), robot swarm, etc. In this work, a small size autopilot system based on STM32 microcontrollers is designed and a quadrotor platform made with...
In this paper, we propose a method to estimate the disturbance information using repetitive technique based on a disturbance map. The disturbance map is shared among unmanned aerial vehicles (UAVs) during platoon flight. Shared map improves the estimated accuracy of disturbance observer via repetitive technique, referred as repetitive estimation. Using the estimated disturbance information, the disturbance...
This paper presents a novel two channel control law for high transparency teleoperation under time delay with guaranteed delay independent L2 stability. Four channel controllers have long been known to provide transparent teleoperation when time delay does not exist on the communication channels. However under time delay, a trade-off between delay and transparency must be made to make the system stable...
This paper proposes a novel design method of disturbance observer (DOB) and reaction force observer (RFOB) for acceleration-based bilateral control (ABC) utilizing DC brushed motor (abbreviated as DC motor later). ABC is one of the control method to enable the transmission of haptic sensation between master and slave robots. In order to transmit highly precise haptic sensation, both DOB and RFOB are...
In this paper a search for the trajectory that minimizes the cost function is studied. In robotic studies the cost function can be defined as a function of time, tracking error or applied torque. In this study the cost function is selected as a function of applied torque, so the main aim is minimizing the energy consumption. For this purpose a simple robot manipulator is chosen, and its kinematic...
Pointing and calling is a method of preventing human error, which is widely used in Japanese industry. Pointing and calling also has the potential to reduce human error in hospital nursing duties. The development and evaluation of novel technologies are necessary to distinguish if pointing and calling is to be appropriately applied in this context. In this paper, we report on an automatic evaluation...
This manuscript describes a robot interaction for driving assist system of a micro electric vehicle (MEV). A driving assist system has been developed for ordinary car. However, almost driving assist system are one-way communication. We propose an interactive driving support system which a robot is installed in a MEV. As a first step, we propose a driving evaluation system applying a simplified fuzzy...
Many robotics applications require smooth orientation planning, i.e. interpolation or approximation of a frame orientation through prescribed configurations such that the angular velocity and its time derivatives are smooth. This for instance ensures the continuity of the motor torques of robotic manipulator. Yet no satisfactory solution to this problem has been presented. This paper presents a solution...
Robot interaction with the environment is normally described as a mass-spring-damping impedance model and the estimation of such interaction impedance parameters requires the computation of the joint (or task) space velocity and acceleration. In many cases, the velocity and acceleration are computed by numerically computing the first and second derivatives of the sensed position signal. The numerical...
Complex tasks are often handled through software implementation in combination with high performance processors. Taking advantage of hardware parallelism, FPGA is breaking the paradigm by accomplishing more per clock cycle with closely matched application requirements. With the aim to minimise computation delay with increase in map's size and geometric constraints, we present the FPGA based combinatorial...
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