Gantry robots have many advantageous properties. They are geometrically simple, like the Cartesian robot, with the corresponding kinematic and dynamic simplicity. For the same reasons, the gantry robot has a constant arm resolution throughout the workspace. The gantry robot has better dynamics than the pedestal-mounted artesian robot, as its links are not cantilevered. One major advantage over revolute-base robots is that its dynamics vary much less over the workspace. This leads to less vibration and more even performance than typical pedestal-mounted robots in full extension Gantry robots are much stiffer than other robot configura tions,although they are still much less stiff than Numerical Control(NC)machines. The gantry robot can straddle a workstation, or several workstations for a large system, so that one gantry robot can perform the work of several pedestal-mounted robots. As with the Cartesian robot, the gantry robot's simple geometry is similar to that of an NC machine, so technicians will be more familiar with the system and require less training time. Also, there is no need for special path or trajectory computations. A gantry robot can be programmee directly from a Computer-Aided Design( CAD)system with the appropriate interface, and straight-line motions are particularly simple to program. Large gantry robots have a very high payload capacity. Small, table-top systems can achieve linear speeds of up to 40 in. s(1.025 m/s), with a payload capacity of 5.0 lb(. 26 kg) making them suitable for assembly operations. However, most gantry robot systems are not as precise as other configurations, such as the SCARA configuration. Additionally, it is sometimes more difficult to apply a gantry robot to an existing workstation, as the workpieces must be brought into the gantry's work envelope, which may be harder to do than for a pedestal-mounted manipulator. Gantry robots can be applied in many areas. They are used in the nuclear power industry to load and unload reactor fuel rods. Gantry robots are also applied to materials-handling tasks, such as parts transfer, machine ading, palletizing, materials transport, and some assembly applications. In addition, gantry robots are used for process applications such as welding, painting, drilling, routing, cutting, milling, inspection, and nonde The gantry robot configuration is the fastest-growing segment of the robotics industry. While gantry robots accounted for less than 5% of the units shipped in 1985, they are projected to account for about 30% of the robots by the end of the 1990s. One reason for this is summed up in Long [1990], which contains much more information on gantry robots in general Currently gantry robot cells are being set up which allow manufacturers to place a sheet of material in the gantry's work envelope and begin automatic cutting, trimming, drilling, milling, assembly and finishing operations which completely manufacture a part or subassembly using quick-change tools and pro- Additional Information The above six configurations are the main types currently used in industry. However, there are other configu rations used in either research or specialized applications. Some of these configurations have found limited application in industry and may become more prevalent in the future. All the above configurations are serial-chain manipulators. An alternative to this common approach is the parallel configuration, known as the Stewart platform [Waldron, 1990]. This manipulator consists of two platforms connected by three prismatic linkages. This arrangement yields the full six DOF motion(three position, three orientation) that can be achieved with a six-axis serial configuration but has a comparably very high stiffness. It is used as a motion simulator for pilot training and virtual reality applications. The negative aspects of this configuration are its relatively restricted motion capability and geometric complexity. The above configurations are restricted to a single manipulator arm. There are tasks that are either difficult or impossible to perform with a single arm. with this realization, there has been significant interest in the use of multiple arms to perform coordinated tasks[Bonitz and Hsia, 1996]. Possible applications include carrying loads that exceed the capacity of a single robot, and assembling objects without special fixturing. Multiple arms are particularly useful in zero-gravity environments. While there are significant advantages to the use of multiple robots, the complexity, in terms of kinematics, dynamics, and control, is quite high. However, the use of multiple robots is opening new areas of application for robots. e 2000 by CRC Press LLC© 2000 by CRC Press LLC Gantry robots have many advantageous properties. They are geometrically simple, like the Cartesian robot, with the corresponding kinematic and dynamic simplicity. For the same reasons, the gantry robot has a constant arm resolution throughout the workspace. The gantry robot has better dynamics than the pedestal-mounted Cartesian robot, as its links are not cantilevered. One major advantage over revolute-base robots is that its dynamics vary much less over the workspace. This leads to less vibration and more even performance than typical pedestal-mounted robots in full extension. Gantry robots are much stiffer than other robot configura￾tions, although they are still much less stiff than Numerical Control (NC) machines. The gantry robot can straddle a workstation, or several workstations for a large system, so that one gantry robot can perform the work of several pedestal-mounted robots. As with the Cartesian robot, the gantry robot’s simple geometry is similar to that of an NC machine, so technicians will be more familiar with the system and require less training time. Also, there is no need for special path or trajectory computations. A gantry robot can be programmed directly from a Computer-Aided Design (CAD) system with the appropriate interface, and straight-line motions are particularly simple to program. Large gantry robots have a very high payload capacity. Small, table-top systems can achieve linear speeds of up to 40 in./s (1.025 m/s), with a payload capacity of 5.0 lb (2.26 kg), making them suitable for assembly operations. However, most gantry robot systems are not as precise as other configurations, such as the SCARA configuration. Additionally, it is sometimes more difficult to apply a gantry robot to an existing workstation, as the workpieces must be brought into the gantry’s work envelope, which may be harder to do than for a pedestal-mounted manipulator. Gantry robots can be applied in many areas. They are used in the nuclear power industry to load and unload reactor fuel rods. Gantry robots are also applied to materials-handling tasks, such as parts transfer, machine loading, palletizing, materials transport, and some assembly applications. In addition, gantry robots are used for process applications such as welding, painting, drilling, routing, cutting, milling, inspection, and nonde￾structive testing. The gantry robot configuration is the fastest-growing segment of the robotics industry. While gantry robots accounted for less than 5% of the units shipped in 1985, they are projected to account for about 30% of the robots by the end of the 1990s. One reason for this is summed up in Long [1990], which contains much more information on gantry robots in general: Currently gantry robot cells are being set up which allow manufacturers to place a sheet of material in the gantry’s work envelope and begin automatic cutting, trimming, drilling, milling, assembly and finishing operations which completely manufacture a part or subassembly using quick-change tools and pro￾grammed subroutines. Additional Information The above six configurations are the main types currently used in industry. However, there are other configu￾rations used in either research or specialized applications. Some of these configurations have found limited application in industry and may become more prevalent in the future. All the above configurations are serial-chain manipulators. An alternative to this common approach is the parallel configuration, known as the Stewart platform [Waldron, 1990]. This manipulator consists of two platforms connected by three prismatic linkages. This arrangement yields the full six DOF motion (three position, three orientation) that can be achieved with a six-axis serial configuration but has a comparably very high stiffness. It is used as a motion simulator for pilot training and virtual reality applications. The negative aspects of this configuration are its relatively restricted motion capability and geometric complexity. The above configurations are restricted to a single manipulator arm. There are tasks that are either difficult or impossible to perform with a single arm. With this realization, there has been significant interest in the use of multiple arms to perform coordinated tasks [Bonitz and Hsia, 1996]. Possible applications include carrying loads that exceed the capacity of a single robot, and assembling objects without special fixturing. Multiple arms are particularly useful in zero-gravity environments. While there are significant advantages to the use of multiple robots, the complexity, in terms of kinematics, dynamics, and control, is quite high. However, the use of multiple robots is opening new areas of application for robots