Arc welding is a tedious process, requiring skill. The system shown in Fig. A shows a simple, low cost system. The system consists of two parts (i) automatic torch guidance and (ii) automatic process sequencing.
     The former is a mechanised template-guided machine having two horizontal slides X and Y. A drive unit with a circular electromagnetic tracer is mounted on these slides. As the circular electromagnet rotates, it rolls along the priphery of the template. A welding torch, mounted on the same beam traces a profile similar to the template.
      A typical welding operation needs an appropriate  sequence  of activities, which is

Fig.B shows a gripper, holding a sugar cane piece. A segmental mechanism with simple links and pulleys is used. The mechanism is actuated by a pair of wires - one being a "gripper wire" and the other a "release wire." These wires pass from the base to the tip of the fingers. The torque at any joint is decided by the radius of pulley at that joint.
       A closed loop system using strain gange sensor and 3 way direction control valve is used to control the gripping force. The sensor is made up of four strain gauges, mounted on a mild steel block. The signal from the bridge is amplified and compared with a set voltage in a comparator. The output signal activates a simple electro-pnematic system.       

        With finger-like configuration, it is a very adaptible, flexible gripper which takes the shape of the component-like human fingers