Design And Procedure Experiment Of Mag Inverter Welding Power Source For Special Welding Robot

As the technologies of industrial robots develop, the robots’ welding system has been widely used in the industry, welding robots needs more and more instantaneity and stability from the coressponding welding power scource. To fullfil the gamut welding of the robots, the power source must be able to respond immediately to ensure the output precisely following the index value.This research introduced the welding power system based on double controlling cores of DSP+MCU, and analyzed its inner structure and mechanism, and propounded several modules designing programs including main circuits, main controlling circuits, wire feeder, man-machine interactive system and communication interface modules. And we investigated the modules from both aspects of hardware and software.In order to eliminate the impairing from the switch, we adopted the form of soft switching full bridge inverter in the main circuits, and used the soft-switching technology of phase-shifted resonance oscillation. The new topotogical structure solved the inversion problem in the all-loaded district when the soft switching cirsuits were applied to the inverter power, and raised the efficiency of the power source to 89%. In the mean time, it analyzed the mechanism of the technology of phase-shifted PWM controlling, in which the UCC3859 chip was chosen to fulfill this process, and ensured the stable and highly-efficient working process of the main circuits.Besides the analysis of the droplet transfer process for MAG welding and the investigation and comparison among the several electric arc controlling methods broadly used here and abroad, we propounded an electric arc controlling methods based on Model Reference Adaptive Control(MRAC), in which by collecting the feedbacks from the arc voltage and the welding electric current and obtaining controlling parameter array, through super-stable-theory-design-based MRAC methods, to regulate the wave pattern of the electric current, hence guarantee the specialty of the constant voltage and stabilization of the arc length of the welding power source. We also demonstrated the working characteristics and minimum system of the MC56F8323 chip at great length, and designed a main controlling system for it. On the part of hardware, switch power circuit, sample-controlling and adjusting circuit, low-voltage and overcurrent protection circuits were designed; on the part of software, the programming environment of MC56F8323 was introduced, and the flow chart of the main program and subprograms of arc strike, arc stopping and wave patterns, accompanied with programming, were mapped. Notably, in the process of designing, we took the interference-resistance of both hardware and software in full consideration.Next, we tested the properties of the welding power source through measuring the welding parameter and wave patterns of arc starting, welding, arc stopping and short circuit in the process of welding on a 5mm-thick type 12 carbon-steel plate.In the crafts trial, we tested multiple welding technologies, including steel construction MAG welding by robots, Al-alloy MIG welding by robots and coordinate welding by double robots. Also, the power source was paired with the pipe’s welding robot auto-cart to operate welding on the long-distance transport pipes, through which we obtained explicit data and built the expert system of all-position welding, which can act as a reference for the robot welding.After repeatedly testing, we discovered some defects which was negelected during the process of designing. After analysis and discussion, we drew several resolution proposals according to some specific defects which led us to the success on the upgrading of the welding power. The testing results shows that the response volecity and stability of the power source we have improved fully meets the requirements of the welding robots, and its simplicity in hardware circuit structure, good inteference-resistence ability, promptness in readout and write-in software and multiple functions all make it a perfect candidate to the robots welding system, which proves the importance of our work.