Master-Slave Manipulators (MSMs) are the most widely used remote handling tools in nuclear industry. Bhabha Atomic Research Centre (BARC) has developed various models of master-slave manipulators with different payloads and ranges. They are used in various hot cells in BARC and other DAE units. Extended Reach Master Slave Manipulator (ERM) is a recent addition to this list. ERM has low friction compared to other manipulators

Features

ERM has 6 independently controlled joints (6 DOF) for arbitrary positioning and orienting the object. Power is transmitted from the master to the slave through stainless steel wire ropes, stainless steel tapes and a parallelogram mechanism. To reduce the operator's effort, the manipulator joints are mechanically balanced in all configurations. The first 3 axes of the manipulator are provided with electrical indexing motions. 

Advantages

It increases the range of slave arm, improves operator ergonomics, provides better viewing, and helps to orient the slave for insertion of the manipulator into the hot cell.

Specifications

Extended Reach Master Slave Manipulator has 9 kg payload and a reach of 3.4 m.

Application

Remote handling of radioactive materials in hot cells

Master-slave manipulators (MSMs) are the most widely used general purpose remote handling tools used in nuclear industry. In master-slave manipulation, human being is within the process, and his abilities are extended to the remote place. An MSM has two arms: the slave arm, which is usually located in the hot cell and the master arm in the control station. When the operator grasps and manipulates the master arm, the motion of his hand is reproduced at the slave arm, performing the necessary task. In most of the cases, the master arm and the slave arm are made geometrically similar to each other. MSMs are usually employed in pairs and the operator manipulates the master arms using both his hands. A through tube which passes through a thick concrete wall shielding separating hot cell and the operating area connects the master and slave arms. Lead glass shielding window is used for viewing the hot cell from outside. From the operating area, operator moves the handgrip of the master and the motion is reproduced on the tong of the slave in the remote area.  

Description

Extended Reach Master Slave Manipulator has 6 independently controlled joints (6 DOF) for arbitrary positioning and orientating the object. Power is transmitted from the master to the slave through stainless steel wire ropes, stainless steel tapes and a parallelogram mechanism. To reduce the operator's effort, the manipulator joints are mechanically balanced in all configurations. The first 3 axes of the manipulator are provided with electrical indexing motions. It increases the range of slave arm, improves operator ergonomics, provides better viewing, and helps to orient the slave for insertion of the manipulator into the hot cell.
Extended Reach Master Slave Manipulator is sophisticated equipment, consisting of assembly of a large number of parts. A very high degree of reliability has been built into the equipment to avoid costly breakdowns. Selection of raw materials has been done for high strength to weight ratio of parts and corrosion resistance 

Specifications

Extended Reach Master Slave Manipulator has 9 kg payload and a reach of 3.4 m.

Application

Remote handling of radioactive materials in hot cells

Infrastructure Required

1. Manufacturing Processes Involved

Most of the parts used in the manipulators are of Stainless Steels (SS-304, SS-410) and Aluminium Alloys (Al-6061-T6, Al-7075-T6 and Al-LM-11). The job is assembly intensive. It involves assembly of large number of fabricated parts, ball bearings, gears, metallic wire ropes, metal tapes, clutch wire, fasteners etc. The following are the manufacturing processes involved in making the manipulator :

• Machining: Turning, Milling, Drilling, Grinding, Tapping
• Spur Gear and Bevel Gear Manufacture: Gear Generation, Grinding 
• Casting of Al- LM-11, Lead
• Heat Treatment of SS-410, Al-LM-11
• Anodising, Cadmium Plating, Hard Chrome Plating
• Welding of SS-304 (TIG Welding)
• Crimping and Brazing of SS wire ropes
• Electrical: Wiring, Soldering, etc.
• Inspection of parts and sub-assemblies.

2. Machine Tools/ Equipments needed for Manufacture :

• Lathe, milling machine, drilling machine
• Precision tool room machines: lathe, milling machine
• Inspection: height gauge, profile projector
• Universal grinding machine 
• Crane: 2 T Capacity

Space Required

• Workshop of size 12m x 8m x 6m height for manufacturing and fabrication of components
• Dust free room of size 10m x 8m x 6m height for precision assembly

Manpower

8 persons consisting of 2 engineers and 6 technicians for fabrication, assembly and testing of Extended Reach Master Slave Manipulator.