机械手类毕业设计外文文献翻译-可迅速布置的机械手系统(编辑修改稿)

机械手类毕业设计外文文献翻译-可迅速布置的机械手系统(编辑修改稿)内容摘要：

the tachometer, and a 12 bit D/A converter to control the motor amplifier。 we have used an oftheshelf motor amplifier (Galil Motion Control model SSA8/80) to drive the DCmotor. For modules with more than one degreeoffreedom, for instance a wrist module, more than one such daughtercard can be stacked onto the same motherboard. 6 3 Integrated quickcoupling connectors To make a modular manipulator be reconfigurable, it is necessary that the modules can be easily connected with each other. We have developed a quickcoupling mechanism with which a secure mechanical connection between modules can be achieved by simply turning a ring handtight。 no tools are required. As shown in Figure 5, keyed flanges provide precise registration of the two modules. Turning of the locking collar on the male end produces two distinct motions: first the fingers of the locking ring rotate (with the collar) about degrees and capture the fingers on the flanges。 second, the collar rotates relative to the locking ring, while a cam mechanism forces the fingers inward to securely grip the mating flanges. A ball transfer mechanism between the collar and locking ring automatically produces this sequence of motions. At the same time the mechanical connection is made,pneumatic and electronic connections are also established. Inside the locking ring is a modular connector that has 30 male electrical pins plus a pneumatic coupler in the middle. These correspond to matching female ponents on the mating connector. Sets of pins are wired in parallel to carry the 72V25A power for motors and brakes, and 48V–6A power for the electronics. Additional pins carry signals for two RS485 serial munication busses and four video busses. A plastic guide collar plus six alignment pins prevent damage to the connector pins and assure proper alignment. The plastic block holding the female pins can rotate in the housing to acmodate the eight different possible connection orientations (8@45 degrees). The relative orientation is automatically registered by means of an infrared LED in the female connector and eight photodetectors in the male connector. 4 ARMbus munication system Each of the modules of the RMMS municates with a VMEbased host interface over a local area work called the ARMbus。 each module is a node of the work. The munication is done in a serial fashion over an RS485 bus which runs through the length of the manipulator. We use the ARCNET protocol [1] implemented on a dedicated IC (SMC COM20200). ARCNET is a deterministic tokenpassing work scheme which avoids 7 work collisions and guarantees each node its time to access the work. Blocks of information called packets may be sent from any node on the work to any one of the other nodes, or to all nodes simultaneously (broadcast). Each node may send one packet each time it gets the token. The maximum work throughput is 5Mb/s. The first node of the work resides on the host interface card, as is depicted in Figure 6. In addition to a VME address decoder, this card contains essentially the same hardware one can find on a module motherboard. The munication between the VME side of the card and the ARCNET side occurs through dualport RAM. There are two kinds of data passed over the local area work. During the manipulator initialization phase, the modules connect to the work one by one, starting at the base and ending at the endeffector. On joining the work, each module sends a datapacket to the host interface containing its serial number and its relative orientation with respect to the previous module. This information allows us to automatically determine the current manipulator configuration. During the operation phase, the host interface municates with each of the nodes at 400Hz. The data that is exchanged depends on the control mode—centralized or distributed. In centralized control mode, the torques for all the joints are puted on the VMEbased realtime processing unit (RTPU), assembled into a datapacket by the microcontroller on the host interface card and broadcast over the ARMbus to all the nodes of the work. Each node extracts its torque value from the packet and replies by sending a datapacket containing the resolver and tachometer readings. In distributed control mode, on the other hand, the host puter broadcasts the desired joint values and feedforward torques. Locally, in each module, the control loop can then be closed at a frequency much higher than 400Hz. The modules still send sensor readings back to the host interface to be used in the p。