Pneumatic Robotic Finishing Tool With Compact Multi-Piston Compliance
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Solution Overview
Problem
Conventional pneumatic robotic tools face issues with force control, compliance, and contamination due to large piston sizes, telescoping actions, and rigid pneumatic fluid supply lines, which affect precision and maintenance.
Innovation Solution
The use of multiple double-acting pneumatic pistons distributed around the tool housing for passive force control and compliance, combined with filtered breather vents and a sealed air pressure equalization system, and a flexible pneumatic fluid supply tube to isolate mechanical forces and prevent dust infiltration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional pneumatic piston is used for passive force control, then force control is achieved, but the tool stack height increases
Solution Approach 1:
The single large pneumatic piston is segmented into multiple smaller pneumatic pistons distributed around the periphery of the tool housing. This segmentation allows the same force control function to be achieved while reducing the overall stack height, as the smaller pistons can be arranged in a compact circular pattern rather than requiring a single large axial space
Solution Approach 2:
The design transitions from a single-axis piston arrangement to a multi-dimensional distributed configuration. Multiple pistons are arranged around the periphery in a circular pattern, utilizing the radial dimension to achieve force control while minimizing axial stack height. This dimensional redistribution allows compact integration of the force control mechanism
2Object-affected harmful factors
If the tool is sealed to prevent dust infiltration, then contamination is reduced, but compliance motion is counteracted by pressure differential
Solution Approach 1:
A filtered breather vent system serves as an intermediary between the sealed tool interior and the external environment. The vent includes a filter that allows air pressure equalization while blocking dust and particulates, thus maintaining both the seal integrity for contamination prevention and the pressure balance needed for compliance motion
Solution Approach 2:
The sealing system uses flexible sealing elements that can accommodate the telescoping compliance motion while maintaining the seal. The filtered breather vent incorporates filtering media that allows gas permeation while blocking solid particulates, enabling pressure equalization without contamination
3Strength
If rigid pneumatic fluid supply lines are used, then structural integrity is maintained, but mechanical forces and torque are transmitted to the motor
Solution Approach 1:
A flexible pneumatic hose serves as an intermediary between the rigid external supply line and the motor. This flexible connection isolates the motor from mechanical forces, impacts, and torque transmitted through the supply line, while still providing reliable pneumatic fluid delivery. The flexible hose absorbs mechanical disturbances without transmitting them to the motor
Solution Approach 2:
The pneumatic supply system transitions from rigid connections to flexible hoses for the motor supply connection. The flexible hose provides both mechanical flexibility to isolate the motor from external forces and functional reliability to deliver pneumatic fluid consistently. This flexible connection maintains structural integrity of the overall system while protecting motor operation stability
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
This configuration results in a compact design with improved force control and reduced contamination, maintaining ambient pressure and preventing mechanical interference, thus enhancing the precision and reliability of pneumatic robotic tools.
Implementation Method 1
the air behind the piston is compressible, and provides some amount of natural compliance
Implementation Method 2
filtered breather vents and an air pressure equalization passage maintain ambient atmospheric pressure throughout the tool, while preventing the infiltration of dust and other particulates
Data Source
AI summary
A pneumatic robotic tool, such as grinder, sander, etc., implements passive force control and compliance using two or more double-acting pneumatic pistons distributed about a pneumatic motor within the tool housing. The multiple pistons facilitate a compact design, reducing tool stack height, as compared to prior-art, single-piston designs. In one embodiment, filtered breather vents and an air pressure equalization passage maintain ambient atmospheric pressure throughout the tool, while preventing the infiltration of dust and other particulates. In one embodiment, a hard port rigidly affixed to the tool housing is provided for at least motor supply pneumatic fluid. The motor supply air is transferred from the hard port to the pneumatic motor via a flexible pneumatic fluid tube within the tool housing. In one embodiment, the pneumatic motor discharge air is vented from the tool housing in a sealed passage that accommodates the tool compliance motion, and prevents dust infiltration.