Getting closer with remotes

Most cranes these days run an on-board computer network that links sensors - strain gauges, boom extension cylinders, pressure and angle sensors - and the processors that monitor and interpret this information, and send it to the crane cab. Radio remote controls that connect to this network gain new access to information that may change the way they are used in the future.

"CAN-Bus is becoming the communication standard of choice on mobile hydraulic machinery," says Antonio Silvestri, Autec managing director. "Crane manufacturers are putting the sensors, the logic units and the remote controls receiving unit on the CAN network; this choice helps to obtain a greater flexibility in upgrading the machine functions and to improve diagnostic and service features."

HBC-Radiomatic product manager Ralf Stegmeyer also argues that networked controllers are growing in popularity, but slowly. "Due to the very sensitive activation especially of PWM (pulse-width modulation) valves, many valves are still directly controlled by a PWM output."

To be networked, remote controls need new technology - particularly serial interfaces, from relay and proportional inputs and outputs. Crane sensors and actuators are also changing, Stegmeyer says.

With networked radio remote controls, "Communication between man and machine is much more comprehensive," he says. "Machine relevant data such as weight, working hours, abrasion and so on are transmitted and displayed. OEM systems can be released for just a special type of application, and be locked for all other types of cranes."

Silvestri of Autec says: "Also radio remote controls are changing. It is possible to use [networked] radio remote controls not only as a command console but also as a means to perform set-up, obtain diagnostic functions and receive information about machine working conditions and status."

“Hirschmann controller product manager Juergen Baesel”

In between pulling a lever and a crane responding, there can be a lot of logic and safety actions

In other words, this sort of control can do more, and can create a safer crane.

"All of the functions that you operate with a remote control can be interpreted by application software, according to application software outputs," says Hirschmann controller product manager Juergen Baesel. "Between that there can be a lot of logic and safety applications. Certain actions or activities can only be done if certain conditions are true or not true."

A remote control with data feedback display can interact with a crane in a new way, says Stegmeyer at HBC-Radiomatic. "The feedback display on such systems is not just suitable for monitoring crane values and properties but also for entering commands. For example, to transmit an exact destination for an automatic move an input on a display is particularly suitable. You can set a value i.e. from 000.00m up to 999.99m in steps of 1cm. This is possible with a special input technology on the display. This is done by our iCON control multi-function switch working as an encoder."

Sophisticated radio controls can also improve safety, he adds. "In combinations of many cranes, for example, radio communication helps to define dynamic safety areas. This increases the efficiency of the cranes. It depends on the application if a movement's acceleration is finely controlled. For example, the movements of a 60m boom of a concrete pump has to be controlled proportionally, otherwise it would be a risk for man and machine. The massive torque on all the material would result in big jumps on the end of the boom instead of smooth movements."

But new technology must still be managed carefully. Hirschmann's Baesel points out that remote controls can be too helpful. With remote controlled-outriggers, operators would not need to bother to walk around to the other side of the crane to make sure that nothing is in the way of the extending outrigger. Because of the safety risks, EN 13000 prohibits remote controls pushing out outriggers, he says.