Handy systems

Remote controls on cranes and hoists are increasingly useful and the technology in them is becoming more advanced, allowing more and more functionality. In the world of cranes, particularly overhead travelling, tower and truck loader cranes, they are becoming an increasingly familiar sight.

These devices bring both safety advantages and productivity improvements. In industry remote controls allow personnel to stand away from dangerous processes or loads, from hazardous emissions or from high temperatures in furnaces and the like. In construction a single person, acting as both operator and his own banksman, can stand near to a point of delivery to guide a load into position, eliminating complex hand signals or walkie-talkie communications. 'Blind' operations by a crane driver are reduced.

The trend to fit remotes can only continue and some industry players now expect that in the not so distant future nearly all cranes will be fitted with a remote facility as standard when they leave the factory.

Tower crane manufacturer Liebherr-Werk Biberach says that 'nearly all bottom-slewing tower cranes are operated via remote control'. Larger capacity top-slewing cranes show the same trend, the company says, and it is only with Liebherr's largest top-slewing cranes from the 280 EC-H size upwards that remote controls are unlikely to be supplied.

The same picture is presented by overhead crane and hoist producer KCI Konecranes, which says that radio control usage in industrial crane applications is still growing continuously all over the world. In Scandinavia and the UK more than 50% of its crane deliveries include radio control. Konecranes UK managing director Gordon Adie says: 'Today, more and more simple industrial cranes and even solo hoists are equipped with radio controls. Also, tandem operation of two cranes is getting more popular. This allows a larger tandem lift every now and then, still leaving crane operators with the possibility to use the cranes individually in normal daily operation. In tandem applications, an interlocking function between cranes with a fixed radio transmitter-receiver brings additional safety to the operation.

'At the same time, many of our process and special cranes customers are already using radio controls in various applications. They are also using radio control in the communication between different parts of the crane, such as hoist machinery and external loading devices, thus reducing hard wiring and associated mechanical cable drums and cable chains.'

Taiwanese firm Telecrane, which produces a range of radio controls, is also optimistic about future growth. Like many Asian suppliers, it is looking to expand from an existing strong market position in east Asia into Europe and North America. It claims a 25% annual growth rate for its radio controls, partly due to competitive pricing.

Overseas sales manager Connie Wang says that the US market is likely to grow fast and believes it could be the number one overseas market for Telecrane in the next two or three years.

For Paul Johnston, UK sales director for Spanish remote control maker Ikusi, technological advances are such that 'we will see a day in the near future when all cranes whether they be overhead, tower or hydraulic will be fitted with radio control as standard.'

Supporting this view perhaps is the recent installation of a remote radio control on a tower crane at the UK's National Construction College. The facility in Norfolk provides safety, equipment and construction skills training for operatives and managers. It has been getting more and more requests for remote control training and so recently took delivery from Vanson Cranes of a Raivan (Raimondi) luffing jib LR60 crane fitted with a radio control.

The college is still cautious about the use of remote control. Training manager Terry Carver says that on large and busy sites where several bigger cranes are working, it will still be better to have an operator in a cab to avoid conflicts and collisions. But training will now be available for smaller sites and for single lifting units, with the operator properly trained to know when each method is more appropriate and how to use the tools available.

New trends

Meanwhile new trends are apparent in remote technology that will expand their use, particularly in factories where limited function lifts and hoists are often remotely operated.

First off, many manufacturers are offering smaller units, both with a limited range of functions for smaller equipment and also with newly developed technology. These units offer one-hand machine operation or are simply easier to carry and less tiring to carry all day.

For example, Cattron Theimeg offers a one-handed unit in its new 100 Series, the TC 100 Handy, which it says is suited to small overhead three or four motion cranes. The unit has six dual pressure buttons with a perceptible pressure point, three push buttons, an electronic safety switch and a mushroom headed stop function button. The new range also includes the TC Mini which has one single and one dual axis joystick, three push buttons and one three way selector. Customised designs are also available.

Italian firm Ravioli also emphasises compactness and lightness in its two new ranges, the Micro and the Dual. The former is again a double contact button type of control which weighs only 500g; the latter a joystick type. The firm also points to the robustness of the units which it says are made with shock resistant materials, a feature most suppliers also highlight.

Spanish firm Itowa is also featuring compactness and lightness in its new Gold range, declaring it to have 'one of the smallest transmitters in the world at only 270g'. Units have double-speed buttons and the transmitter includes one pushbutton for start and horn, one auxiliary pushbutton, six pushbuttons for movements and one emergency stop button. The new radiotransmitter works in the new 868-870 MHz EC band, minimising the possibility of interferences, Itowa says. The Gold series runs at a lower voltage than previous models with a transmitting power of 5mW which gives a claimed 20 hour continuous working period. Charging takes only four hours.

One of the world's best known makers, Hetronic, which sells off-the-shelf and custom systems for construction and material handling, has launched a special range of smaller units, the Pocket type, designed to serve the low end market, mainly on chain hoists, hoisting systems, conveyor systems, monorails, concrete mixers, tailgates and other machinery. Four different models are engineered to control a limited number of digital functions, two or four dual speed and six and three single speed. 'Lightweight', 'sturdy', and 'thin profile' are again key words in the promotional material.

The units also have MFS (multiple frequency sharing), and various systems to combat interference problems are also being produced by other manufacturers. Hetronic says that its MFS allows up to 20 units to work safely and in close proximity on one frequency.

HBC Radiomatic also has a system to allow multiple units to work closely, including an interference preventor fitted on a new range of crane weighing machines.

Telecrane too highlights this issue and points to its remote setting function which it says allows the transmitter unit to adjust the receiver frequency from a distance in case of interference. This feature is associated with full programmability of the firm's new F21 range of hand held and joystick models with a number of single and double step push button models and five speed touch sensitive joystick units.

Programmability

Programmability is another trend becoming apparent in the market. Programmable units can be re-configured - in Telecrane's case by using a Windows based PC software package - for different types of equipment or for different functions. They can also be configured to precisely required stepped stages; Ravioli highlights this feature on its Dual joystick units.

Swedish company Tele Radio's new 860 system, introduced in 2002 at the Hannover trade fair has a number of programmable functions such as instantaneous/changeover relay functions, interlocking and automatic shut-off. All functions are programmed directly via buttons on the transmitter. Safety has been at the fore during the development of the 860 system, Tele Radio says, with an integrated stop function, safety relays monitored by double microprocessors, personal PIN codes, logging on and off and compliance with EN-954-1 (category 3).

US manufacturer Telemotive Industrial Controls' newest product, the TelePilot crane control system, combines compactness with programmability. It uses a Palm Pilot personal digital assistant to programme the transmitter's synthesized frequency and on-board flash memory configuration via an infrared signal. The lightweight (900g) transmitter features up to five motions and two speed operations and is compatible with other Telemotive systems. The gold contact metal switches have a rated life of more than a million operations.

Increasingly complex software for remote controls also allows more complex functions. This means more tie-ins with the greater complexity of electronic machine controls. Remote units can access complex machine functions or can replace or extend programmable logic controls.

One example is the feedback channel to the crane operator's remote transmitter, which will give more moment to moment information of operations to the operator while monitoring correct and safe crane use.

KCI Konecranes for example says that this kind of feedback channel has been available as a special feature for a high add-on price only on particular systems. But it promises new developments shortly to satisfy increasing demand for load and alarm displays on the remote transmitters on standard units.

This trend is also clear in the truck mounted cane market where leading makers like Austria's Palfinger and Italy's Fassi are developing systems that allow feedback display and integration with crane systems.

In addition to the standard functions of a conventional radio remote control system Palfinger is now offering a remote control panel that incorporates a display showing the capacity loading level of the crane with an overload indicator.

The LED display is complemented by another indicator showing the current capacity loading level of the crane itself. Any overload of the additional knuckle boom, or fly jib, or winch, is also indicated.

The data display uses a digital data transmission system that has a check-back module (CAN bus) between the crane and the control panel, which Palfinger says gives the crane operator a high degree of safety and convenience.

Regardless of the distance from which the crane is being controlled, the control panel display informs the crane operator about the loading capacity on a continuous basis.

The remote panels also tap into electronic functions of the crane which allow more convenient and efficient use of the cranes. They allow activation and de-activation of special systems as well as motor start and stop, rotational speed plus/minus and spotlight. These include the Paltronic 50 that monitors and controls crane functions by electronic data transmission.

Palfinger's Active Oscillation Suppression system (AOS) can also be activated by the remote control and so can its High Power Lifting System (HPLS). AOS is a system to compensate jolts and sudden load changes to make lifting smoother, especially with large loads or long outreaches. HPLS is a mechanism, like a lower gear on a car, to slow down the crane operation in order to gain greater lifting capacity or to allow better positioning of loads. Most leading manufacturers have such a system, although the names they give it varies.

Italian maker Fassi (which calls its slower and stronger mode XP - for 'extra power') says that the developments now taking place bring remote control forward into the 'wholly new concept of integrated machine control (IMC)'. The remote control is just one part of the operation of the whole crane.

What Fassi calls IMC is an adaptation of the electronics seen in the truck and car industry where conventional wiring has been replaced by a single digital wiring circuit using a coded communications protocol called CAN (controller area network) that carries most of the signals from sensors and interfaces throughout the vehicle, separated and micro-processed. On a modern truck, this will mean everything from steering and ABS brakes to engine management and tachograph, through to the global navigation system and lights.

For truck loaders Fassi has developed an 'intelligent' integral machine control system, which it claims, 'receives and selects information from external and internal sources, activates functions in fractions of a second and automatically optimises crane performance'.

A key part of this process is better and faster communication with the operator it says.

The new FX electronic control system, integrates with three functions on cranes of 48tm and above, Fassi says. First is IMC, integrated and intelligent control. Second is automatic dynamic control (ADC) to adjust the speed of the crane's movements within pre-determined safety parameters. And last is radio remote control of all the crane functions, in Fassi's case a Scanreco system worked from a weatherproof portable control on shoulder or waist harness.

The unit has a working radius of 200m and up to eight operating levers, the movements of which are directly proportional to movement of the crane and can give progressive reduction in movement with five speed reductions allowing an 'inching' facility for accurate load placement.

The console allows full control of the engine of the parent truck. Each radio control operates with its own unique identity code and, by working also within a protected radio frequency band, the risk of a frequency collision is avoided.

Fassi is also now offering a remote control diode display replicating all the information given on the display of the parent FX control system and constantly updating data on 'every parameter' of the crane.

Integrated functions are not limited to truck crane systems. Factory and hoist control systems are also increasingly using the ability of remote control units to take over, supplement or replace PLC functions. Control Chief of the USA has recently installed a system at a hot dip galvanising works in Ohio that works together with the programmable logic control system and ties directly into the back plane of the PLC via Control Chief's wireless Communicator TM Module. This technique is implemented in conjunction with the high current relay Watchdog Module which provides a real-time, fail-safe means to shut down in case of emergencies.