The Crane Remote Control Systems (2)

1.4 With wireless remote control system crane characteristics
(1) Reliability
Remote control system once breaks down, will affect the normal operation of production. So the system and hardware must have high reliability.
(2) Safety
Remote control system of crane control device, if the action that will happe is wrong, the accident loss, wounded. Therefore must ensure that remote control system of 100 percent security, with the operator should be able to direct the emergency stop and automatically abrupt stop safety protection.
(3) Strong anti-jamming
It can not be electric welding, such as electric and crane inverter electromagnetic clutter interference, can in the small scope and multiple use, not interfere with each other.
(4) Can be used in bad environment
It must have strong dustproof, gas, oil resistance, impact resistant properties. Light and small operation is convenient.
(5) Launch system is operated by the operator, reason should carry small volume, light weight, easy to carry.

1.5 Existing bridge crane remote control flaw
Crane remote control are not completely popularization, the main reason boils down to the current remote control interface circuit. At present the mainstream remote control interface circuit for relays- contactor controlling. Crane electric drive system used more ending type ac motor, the CAM controller directly control or by Lord command controller release contactor system, to resection of motor rotor resistance of the way, and the operation speed totally on the crane in the cockpit, the traditional remote operation way has the following questions:
(1) Remote operation changed the original crane’s performance
To make remote operation simple, remote control buttons generally less, correspondingly receiver output contacts are also less. General crane cart, car, are main hook and vice hook four agencies, each agency needs at least remote seven points, plus start, abrupt stop and point move and main hook fast, the remote control under need at least 32 points, accept machines need to be 32 single speed buttons or 24 dual speed key, to realize the full function, the operator must operating simultaneously two or more buttons, the operator that feel operation busy, and will cause confusion, forming operator safe hidden trouble, so remote usually set the output points less, so use relay contactor interface can realize the partial function of the crane, usually agencies to speed operation, lost original crane five timings this performance, so the application of remote control technology to form the obstacles.
(2) Poor reliability
Relays-contactor interface circuit must have relay ark, especially complex relay control is the most easy to malfunction link. Two kinds of interface circuit need contactor ark, often in frequent points because crane and other heavy work under dynamic task, hence increasing contactor coils damage, the contacts burning or welded, wiring looseness fault, especially contacts as welding is likely to cause damage to personal and equipment into a major accident, so poor reliability.
(3) Reform of remote is big, electrical maintenance difficulties
Two kinds of interface circuit all need will pick up and remote control interface circuit string of original crane protection circuit, part and taken up in institutions in the main circuit control, so remote control system requires a lot of lead wire, it not only increases workload of remote modification construction, but also for future electrician maintenance system cause difficulties.
Bridge crane has been widely used in metallurgical industry, because within the profession characteristic, metallurgical enterprise bridge crane is often in high temperature, much dust, poisonous gas and danger of working environment, in bridge crane operation homework cab driver bad conditions, without effective safeguard the personal safety. And some crane installation position has 30-from the ground, because 40m sight is not clear, crane operation must have the ground staff by the command, but sometimes can proceed with improper, due to command the existing great potential accident.
Crane remote operation, it improved operator operating environment, and widened the field of vision, personnel increased operating personnel’s personal safety and reduce the operating personnel quantity, raise the efficiency.
Taking 10t bridge crane, for example, with s7-200PLC + remote + deceleration motor as a remote control interface circuit of the system hardware and software design. Composed by the remote control system of interface circuit with safe and reliable, simple operation, easy maintenance, low cost off a system. The crane can realize all control function.