In this paper we propose an energy control based algorithm for performing swing-up regrasping. In... more In this paper we propose an energy control based algorithm for performing swing-up regrasping. In such regrasping motion, an object is manipulated using a robotic arm around a point pinched by the arms gripper. The aim is to manipulate the object from an initial angle to regrasp it on a new desired angle relative to the gripper. The pinching point function as a semi-active joint where the gripper is able to apply only dissipative frictional torques on the object to resist its motion. We address the problem by proposing an algorithm based on energy control. Simulations on a three degrees of freedom manipulator regrasping a bar validate the proposed algorithm.
In this work we present a library of methods to perform dynamic regrasping to alternate grasp con... more In this work we present a library of methods to perform dynamic regrasping to alternate grasp configurations of an object with respect to the task to be done. In these methods, we utilize the dynamics of the arm and therefore can use a simple non-dexterous gripper, enabling fast manipulations and low costs. We investigated two regrasping methods. One is an in-hand orienting approach where the gripper changes its orientation relative to a falling object. We have developed a novel stochastic motion planning algorithm that can be used for the in-hand regrasping manipulation under kinematic and dynamic constraints. The second is termed swing-up regrasping where an object is manipulated using a robotic arm around a point pinched by the arms gripper. The pivot point is modeled as a semi-active joint where only dissipative torques can be exerted and can only resist the motion of the object. We utilize an impulse-momentum approach to swing up the object and then a Clipped Linear Quadratic Regulator (cLQR) controller to stabilize the object in its desired angle. We also introduce the use of energy control for swinging-up the object.
ABSTRACT This paper presents a novel design and a motion planner for a semipassive mobile robot. ... more ABSTRACT This paper presents a novel design and a motion planner for a semipassive mobile robot. The robot consists of an upper circular body and three identical semi-passive driving mechanisms. Each mechanism consists of a passive wheel that can freely roll, a rotation actuator along the normal axes and a linear actuator for motion along the radial direction of the upper body center. The robot is equipped with an inclinometer to measure the surface slope. Each wheel is also equipped with a rotational encoder to measure roll. Using an odometric model, data from these encoders determines vehicle position. Kinematic analysis provides tools for designing a motion path that steers the robot to the desired location, and determines the singular configurations. Due to the passive roll, there is no longitudinal slippage, and lateral slippage is determined from the kinematic and odometric models. This enables accurate and reliable localization even with slippage. A gait pattern planer for downhill, as well as horizontal and uphill surfaces is presented. A prototype robot has been built and field tested. Experimental results verify the suggested models.
World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, Oct 3, 2013
Tactile sensors are numerous and varied, and the data they provide has proven advantages in indus... more Tactile sensors are numerous and varied, and the data they provide has proven advantages in industrial and consumer products. Despite this fact, these sensors are not used to their full potential. This illustrates the need for low-cost, versatile tactile sensors. In this paper we introduce novel robotic fingertips that use low-cost components coupled with mechanical ingenuity in order to attain important and high-quality tactile data. Our robotic fingertips contain a rolling mechanism, and can sense the force applied to an object, the normal direction of the contact point, as well as parallel movement along the object's surface. We show three main uses for this fingertip. Firstly, we demonstrate how the fingertips can be used for the detection of soft or lightweight objects by applying extremely small forces to them. Secondly, we present a method of full-perimeter definition (location and normal direction) of rigid objects by tracing. Lastly, we explain how our sensors can be used to detect stiffness and stiffness anomalies in soft objects, such as organic tissue.
In this paper we propose an energy control based algorithm for performing swing-up regrasping. In... more In this paper we propose an energy control based algorithm for performing swing-up regrasping. In such regrasping motion, an object is manipulated using a robotic arm around a point pinched by the arms gripper. The aim is to manipulate the object from an initial angle to regrasp it on a new desired angle relative to the gripper. The pinching point function as a semi-active joint where the gripper is able to apply only dissipative frictional torques on the object to resist its motion. We address the problem by proposing an algorithm based on energy control. Simulations on a three degrees of freedom manipulator regrasping a bar validate the proposed algorithm.
In this work we present a library of methods to perform dynamic regrasping to alternate grasp con... more In this work we present a library of methods to perform dynamic regrasping to alternate grasp configurations of an object with respect to the task to be done. In these methods, we utilize the dynamics of the arm and therefore can use a simple non-dexterous gripper, enabling fast manipulations and low costs. We investigated two regrasping methods. One is an in-hand orienting approach where the gripper changes its orientation relative to a falling object. We have developed a novel stochastic motion planning algorithm that can be used for the in-hand regrasping manipulation under kinematic and dynamic constraints. The second is termed swing-up regrasping where an object is manipulated using a robotic arm around a point pinched by the arms gripper. The pivot point is modeled as a semi-active joint where only dissipative torques can be exerted and can only resist the motion of the object. We utilize an impulse-momentum approach to swing up the object and then a Clipped Linear Quadratic Regulator (cLQR) controller to stabilize the object in its desired angle. We also introduce the use of energy control for swinging-up the object.
ABSTRACT This paper presents a novel design and a motion planner for a semipassive mobile robot. ... more ABSTRACT This paper presents a novel design and a motion planner for a semipassive mobile robot. The robot consists of an upper circular body and three identical semi-passive driving mechanisms. Each mechanism consists of a passive wheel that can freely roll, a rotation actuator along the normal axes and a linear actuator for motion along the radial direction of the upper body center. The robot is equipped with an inclinometer to measure the surface slope. Each wheel is also equipped with a rotational encoder to measure roll. Using an odometric model, data from these encoders determines vehicle position. Kinematic analysis provides tools for designing a motion path that steers the robot to the desired location, and determines the singular configurations. Due to the passive roll, there is no longitudinal slippage, and lateral slippage is determined from the kinematic and odometric models. This enables accurate and reliable localization even with slippage. A gait pattern planer for downhill, as well as horizontal and uphill surfaces is presented. A prototype robot has been built and field tested. Experimental results verify the suggested models.
World Academy of Science, Engineering and Technology, International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, Oct 3, 2013
Tactile sensors are numerous and varied, and the data they provide has proven advantages in indus... more Tactile sensors are numerous and varied, and the data they provide has proven advantages in industrial and consumer products. Despite this fact, these sensors are not used to their full potential. This illustrates the need for low-cost, versatile tactile sensors. In this paper we introduce novel robotic fingertips that use low-cost components coupled with mechanical ingenuity in order to attain important and high-quality tactile data. Our robotic fingertips contain a rolling mechanism, and can sense the force applied to an object, the normal direction of the contact point, as well as parallel movement along the object's surface. We show three main uses for this fingertip. Firstly, we demonstrate how the fingertips can be used for the detection of soft or lightweight objects by applying extremely small forces to them. Secondly, we present a method of full-perimeter definition (location and normal direction) of rigid objects by tracing. Lastly, we explain how our sensors can be used to detect stiffness and stiffness anomalies in soft objects, such as organic tissue.
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Papers by Amir Shapiro