Collision avoidance systems can keep cranes isolated without mechanical switches or devices. These systems can be used to prevent impacts between cranes as well as other obstructions. Reducing impacts can improve operator safety and reduce the wear and tear on equipment. Collision avoidance systems can also be used to maintain a minimum distance between cranes to prevent overloading runways and support structure. Keeping cranes segregated used to be done with bumpers, crane spacers, or limit switches. A collision avoidance system typically consists of an optical sensor and a reflector. The reflector is mounted on the crane or object that will be detected. The sensor can be set for multiple distances. This can allow you to use a slowdown and stop function at different distances. Signal lights or alarms can be used to indicate when cranes or objects are being detected. Programming the sensor is very easy. It requires the push of one button when the crane is located at the desired distance from the crane or object. Collison avoidance systems can be installed on new cranes and are easy to retrofit to existing crane systems. The sensor can be integrated into cranes using a VFD or contactor controls.
Adding slowdown & stop controls to a trolley or bridge adds many benefits to crane systems and employee safety. Without this added feature, the only means of stopping a crane or trolley is with the use of end stops. Depending on the size of crane and load being lifting, running into the end stops can put large and unnecessary impact forces on the trolley, crane, runway structure, and even the building. By installing an additional set of sensors and changing a few parameters on the VFD, we can use this function. Now, when the trolley is traveling towards the end stop a sensor will trip, which will then cause trolley to stop right before the end stop is met, eliminating most impact forces. If one more sensor is added to the system, the slowdown function can be implemented. This will allow the trolley to start slowing down at a given point to reduce load swing as much as possible. In addition to reducing load swing and impact forces, the slowdown and stop feature can reduce bridge tread and wheel wear. On a system without the above system, there is nothing stopping the wheels from spinning after the end stops are hit if the operator does not remove their finger from the button. This can cause major damage to the spinning wheels and its running tread. In some cases, wheel divots were formed so deep that the wheels would become trapped. This costly and dangerous damage could be eliminated by adding a slowdown & stop control feature to a crane or trolley.
AFE Crane has the ability of making crane controls as simple as possible or as complex as need to keep employees safe and production running smoothly. We can use a number electrical sensors including: photocells, limit switches, encoders, and laser scanners. A number of other electrical components can be used, including: indicator lights, warning lights or buzzers, relays, programmable logic controllers (PLC’s), DC power supplies, and many more. By using all of the above, AFE Crane can design and develop a system that fits your needs. From creating zoned “no travel” areas, to special building column anti-collision controls for projecting cranes, and adding travel constrains so the hoist cannot lift unless other criteria have been met.
For more elaborate systems including large carriers transporting and queuing parts for a main assembly line, a more intricate control scheme can be used. By using encoders, RFID tags, and scanners, each carrier can be mapped on a computer monitor or touch-pad display. This allows one employee to keep track of any system errors or issues without the need to travel the entire plant. Most of these systems are semi-automated, meaning that once a carrier is loaded the operator will push one button and the carrier will automatically travel to the next required station. These systems can also be integrated with the customer’s shop management software to produce a seamless workflow.