Palm-Mounted 3D Robotic Gripper for Precise Small-Object Manipulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Autonomous robotic manipulation faces challenges in accurately perceiving and manipulating small objects due to insufficient resolution in existing optical systems, calibration errors, and the need for varying gripper stiffness, which limits the robot's ability to perform tasks like screwing and grasping with precision and compliance.
Innovation Solution
A robotic gripper system with a palm-mounted mechanical manipulation system, including independently controllable fingers, a light projector, and stereo camera sensors, which allows for three-dimensional perception and object manipulation by varying stiffness and compliance, enabling precise grasping and manipulation of objects within a workspace.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If optical systems are mounted above the robot's workspace, then the robot can perceive objects in the workspace, but the resolution is insufficient for small objects and the robot cannot dynamically react to changes
Solution Approach 1:
The patent moves the optical system from a fixed overhead position to a mobile platform that operates within the workspace volume, transitioning from two-dimensional planar observation to three-dimensional immersive perception. This enables the robot to perceive small objects at close range with high resolution while maintaining dynamic mobility to react to environmental changes.
Solution Approach 2:
The patent introduces a mobile robotic platform as an intermediary carrier for the optical system. This intermediary enables the optical system to access difficult-to-reach areas and provides dynamic positioning capabilities, allowing the robot to move the sensing system closer to objects of interest for enhanced resolution while maintaining adaptability to environmental changes.
2Measurement precision
If the robot moves outside the work cell during perception, then calibration errors are reduced, but cycle time increases and the robot operates blindly
Solution Approach 1:
The patent performs calibration operations in advance by mounting the optical system on a mobile platform that can be positioned at multiple predetermined locations within the workspace. This preliminary positioning and calibration at various depths and angles enables the system to maintain accurate perception throughout the workspace without requiring the robot to exit the work cell during operation, thus reducing cycle time while maintaining precision.
3Measurement precision
If a single optical sensor is mounted close to the robot's end-effector, then sensing accuracy increases, but the workspace available to the robot is reduced
Solution Approach 1:
The patent employs a mobile optical system that can dynamically reposition itself within the workspace rather than being fixed at a single location near the end-effector. This dynamic positioning capability allows the system to maintain close sensing distances for high accuracy when needed while moving to other positions to preserve access to different areas of the workspace, thus balancing sensing accuracy with workspace availability.
4Manufacturing precision
If the gripper is made stiff, then manipulation precision is improved, but compliance with objects is reduced
Solution Approach 1:
The patent implements variable stiffness control in the gripper mechanism, allowing the structural rigidity parameter to be dynamically adjusted. The gripper can transition between stiff and compliant states based on the manipulation task requirements, enabling precise positioning when stiffness is high while maintaining compliance with objects when stiffness is reduced, thus resolving the contradiction between precision and adaptability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enhances the robot's ability to accurately grasp and manipulate small objects by providing high-resolution 3D perception and adjustable stiffness, improving task performance in tasks like bin picking and peg-in-hole insertion.
Implementation Method 1
at least two camera sensors mounted to, on or in, or connected operably to, the palm and configured and positioned to sense at least one of reflected and backscattered light having the predetermined characteristics and originating from the light projector
Data Source
AI summary
Disclosed are various embodiments of a three-dimensional perception and object manipulation robot gripper configured for connection to and operation in conjunction with a robot arm. In some embodiments, the gripper comprises a palm, a plurality of motors or actuators operably connected to the palm, a mechanical manipulation system operably connected to the palm, a plurality of fingers operably connected to the motors or actuators and configured to manipulate one or more objects located within a workspace or target volume that can be accessed by the fingers. A depth camera system is also operably connected to the palm. One or more computing devices are operably connected to the depth camera and are configured and programmed to process images provided by the depth camera system to determine the location and orientation of the one or more objects within a workspace, and in accordance therewith, provide as outputs therefrom control signals or instructions configured to be employed by the motors or actuators to control movement and operation of the plurality of fingers so as to permit the fingers to manipulate the one or more objects located within the workspace or target volume. The gripper can also be configured to vary controllably at least one of a force, a torque, a stiffness, and a compliance applied by one or more of the plurality of fingers to the one or more objects.