Welding Force Control Using Speed Setpoints for Stable Weld Quality
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Solution Overview
Problem
Current welding technologies face challenges in maintaining consistent force control during the welding process, leading to potential tool damage, poor weld quality, and increased waste due to factors like welding spatter and heat-related expansion, which existing position-controlled systems cannot effectively address.
Innovation Solution
A welding controller with a force control module that outputs speed setpoints to a drive device, enabling the application of a target force that can change over time and compensates for disturbance variables, ensuring consistent weld quality through a PD controller and optional evaluation module for oscillation detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If position control is used to regulate welding gun force, then the welding gun can be protected from damage, but it is not possible to specify a time-varying target force for the welding process
Solution Approach 1:
The patent transitions from static position control to dynamic force control by implementing a force control module that specifies time-varying target forces. The control system dynamically adjusts the force profile during the welding process based on process requirements, enabling adaptive force regulation while protecting the welding gun through integrated force monitoring.
2Reliability
If position control is used to regulate welding gun force, then the welding gun can be protected from damage, but weld spatter leads to an uncontrollable drop in force
Solution Approach 1:
The patent implements a feedback control mechanism where a force sensor continuously monitors the actual force during welding. The force control module compares the measured force with the target force and dynamically adjusts the drive unit output to compensate for disturbances such as weld spatter, maintaining force stability and reliability throughout the welding process.
3Reliability
If position control is used to regulate welding gun force, then the welding gun can be protected from damage, but an increase in force due to thermal expansion of the weld spot cannot be compensated
Solution Approach 1:
The force control module uses real-time feedback from the force sensor to detect force increases caused by thermal expansion. The system automatically compensates for these thermal effects by adjusting the drive unit output to maintain the target force profile, ensuring consistent welding quality despite thermal expansion disturbances.
4Manufacturing precision
If position control is used to regulate welding gun force, then the welding gun can be protected from damage, but compression of components with poor fit cannot be guaranteed
Solution Approach 1:
The patent enables dynamic force regulation that can adapt to poor fit conditions. The force control module specifies time-varying target forces that increase compression on components with poor fit during the welding process, ensuring adequate compression and weld quality while preventing excessive force that could damage the welding gun.
Data Source
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AI summary
A welding control system (10) for a welding tool and a method for force control of a welding tool are provided. The welding control system (10) has a force control module (11) for controlling the force profile (Fs(t); FS_ACT) exerted by at least one electrode of a welding tool on at least one component during the production of a weld joint, wherein the force control module (11) outputs at least one speed setpoint (n_S) to a drive unit (26) of the welding tool in order to control the drive of the welding tool for applying the force (Fs(t); FS_ACT) with a speed controller (261) of the drive unit (26).