Modern crane remote controls need to be future-proof, flexible and safe

Advancing technology requires increasingly future-proof, flexible and operator safety conscious designs.

One of the main issues facing the remote control sector is the ongoing battle for air-space as the number of remote controls in most work environments increases.

Antonio Silvestri, Autec product development manager, says the radio spectrum is becoming very crowded as more wireless devices are used close together. "Frequency-hopping techniques, especially if combined with the intelligent search of free channels, are the key for the co-existence of many radio systems."

Autec launched the Dynamic series in 2010, designed for mobile hydraulic applications. Systems never work on the same frequency but constantly scan the band and move to a free frequency.

In the next 12 months the company will launch the Air 8, a pushbutton handheld unit for industrial lifting applications. It works at different RF power levels, allowing a number of remote controls to be used in the same area. "The system scans the frequency band at start up and starts working at a free frequency; it hops to a different frequency if interference occurs." Combined or single control of different hoists and trolleys is possible through the function key.

Sometimes RF cannot be used due to jamming restrictions. A solution comes in the form of Magnetek's Enrange Flex Pro Tethered CAN-bus controller for mobile hydraulic applications.

The controller includes all the features of the company's lightweight Flex Pro handheld transmitter, including precise proportional control and adjustable speed control, it says. The unit allows one-handed operation, useful for applications when the operator assists in running the machine.

Flex Pro Tethered is ideal for situations when proportional control is needed but RF is not required. This controller can be kept on hand as an inexpensive back-up to prevent costly delays.

Narrow band

Frequency bands, ranging from 400 to 900 MHz, have a great influence on the effect on the design of remote controls. "Since radio remote controls are narrow band devices, they are not able to cover all these different frequencies, making it necessary to use different equipment and modules for each of these frequency bands. One single solution simply cannot cover all of these bands," explains Karl-Heinz Guenther, HBC-radiomatic international key account manager.

As a result harmonisation of these narrow band frequencies for remote controls in the near future is unlikely, adds Guenther. "Common wideband frequencies like wi-fi or Bluetooth could be an alternative but there is the question whether they could be used for radio remote controls, a field where efficiency, range and, most importantly, safety are imperative. The utilisation of these frequency bands would pose another problem. One possibility to harmonise frequency bands would be one single band for all safety remote controls worldwide, which would facilitate the design of such devices. But it is unlikely that this will be realised any time soon."

Silvestri at Autec expands on the point, "[Radio remote controls] obviously meet the requirements of national rules and laws, which are specific to the local situation and difficult to modify or remove. It is therefore difficult to believe that frequencies will be harmonised in the short to middle term."

Another key feature of design is safety. Many operators find themselves in potentially hazardous environments and, over the decades, their safety has become the priority.

Ikusi, for example, is launching the LA70 range limiter for fixed or mobile machinery as part of its TM70 range for hazardous or risky working conditions. The LA70M works with radio remote control equipment with coverage up to 50 m. The system only works under the LA70M range limiter emitter-covered zone and if the radio remote transmitter is in this zone. The operator's working conditions are programmed as required, and there is a choice of modes, including restricted key manoeuvres, key zone programming, start-up key switch programming or limited working condition programming.

The LA70M Range Limiter is compatible with Ikusi TM60 and TM70 ranges, and the controls are available in handheld pushbutton and console box models.

Using RS485 serial communication, the range limiter has master and slave configuration with expansion modules of up to two slaves with one master module.

Overheads

Cattron's new LRC-M1 wireless control system for electric overhead travelling cranes also caters for increasingly stringent safety requirements in industrial applications. It uses the external TransKey RFID configuration which allows facilities to minimise spares and transfer keys to other controllers, which increases safety and flexibility, says the company. The LRC-M1 can control up to four motions with two ergonomic, multi-axis joystick controllers. The trolley and hoist selector, two auxiliary push buttons and toggles are mounted on an impact resistant Lexan (polycarbonate) housing.

HBC-radiomatic has presented an updated version of its handheld micron 5 radio control. It can now be used in potentially explosive areas and is available in models for explosive zones 1, 2, 21 and 22. "The customer now has greater possibilities from which to choose when it comes to radio controls for such hazardous application environments."

The user identification option is another feature of the redesigned micron 5. It is based on a personalised login card - HBC Smart Card - with a credit card-like design.

The company has also introduced new safety features across its range to protect the operator from danger in specific situations. They include the orthogonal drive, which only allows the operator to move the crane in the direction they initially engage with the joystick. Other new features include the radiomatic shock-off, the roll-detect, a vibration alarm and an automatic shut-down on implausible control commands.

According to Autec, international regulatory framework is a significant support as it helps measure the degree of safety that functions remote control functions are designed for. "EN ISO 13849-1 and IEC 62061 define, in fact, quantitative, rather than qualitative, classification of safety functions, thus making them objective data. Manufacturers pursuing safety as their first value find valid references in the latest standards." Says Silvestri.

Keeping the products in good working condition is also an important consideration. Magnetek has rerated its Impulse G+ and VG+ Series 3 adjustable frequency crane controls.

It now has an increased ambient temperature rating of 60 °C (140 °F), for use in high temperature applications.

"Due to customer desire to use our proven IMPULSE Series 3 drives in severe environments, such as steel mills and power plants," said Aaron Kureck, Magnetek product and development manager.

Computer link

As technology advances there is ever greater interactivity between control equipment and computers. Datek has developed a Windows interface for its line of receivers. This makes it possible for customers to combine Profibus, CANopen or relay outputs with a personal computer interface in the same wireless system. For some special applications where there is no need for other communication, the PC interface can be used as standalone.

Crane functions and other safety-critical control functions must not be controlled over the PC interface since Windows doesn't fulfil valid safety standards. The PC interface, however, can be used to enter data into customer-specific OEM software programs, like weights, logistics information, work report numbers, etc. The customer sets up the interface through a Windows DLL-file (Dynamic Link Library) provided by Datek. This offers great flexibility for the customers to setup the system as they wish.

A notable trend in the last 12 months or so is the introduction of colour screens. One of them is the HBC-radiomatic micron 7 transmitter which provides system and feedback information in colour, including, for example, weight load. This increases operator comfort and safety, says the company. The company's spectrum D now has 3.5 inch colour TFT screen. The display is non-reflective, allowing clarity in sunny conditions, says the company. In addition, the TFT has QVGA technology and boasts a colour depth of 18 bits, including a 32 MB internal memory, enabling the display of various graphics, image files and language versions. "With this ability, an intuitive, cross-linguistic menu guide can easily be configured. Furthermore, the saving of various data is also possible, backing up all the critical information needed for the operator," says a spokesman.

Guenther adds that the trends in radio technology follow the trends in crane technology. "For example, with the extended use of interfaces such as CAN-Bus, Profibus or others, radio control technology has been adapted."

Silvestri agrees, "The integration of additional functions as a complement to the traditional control functions, as well as display visualisation and FieldBUS communication are surely in growing demand."

The fast-developing landscape means that flexible, future-proof products are increasingly called for. For example, i-Kontrol from Ikusi is a transmitter that can be adapted to the emergence of new functions. "As new hardware and software electronics are developed, and incorporating greater features than those supported by the current console in the TM70 series," says the spokesman.