Remotes become handier2 December 2002
Adrian Greeman reviews developments in remote control systems and finds that they are getting smaller and more functional
Remote controls on cranes and hoists are increasingly useful and technology in them is becoming more advanced allowing more and more functionality. In the world of overhead travelling cranes, as well as tower and truck loader cranes, they are becoming increasingly familiar.
These devices bring safety advantages as well as 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 control facility as standard when they leave the factory.
KCI Konecranes 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 company Telecrane, which produces a range of industrial 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 North America and Europe. It claims a 25% annual growth rate for sales of 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, sales director for Spanish remote control maker Ikusi in the UK, 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".
New trends in technology are apparent which will expand the use of remote controls, particularly in factories where limited function lifts and hoists are often remotely operated.
First off, many manufacturers of remote control systems 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 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 speed pushbuttons with a perceptible pressure point, three pushbuttons, an electronic safety switch and a mushroom headed stop function button.
The new range also includes the TC Mini which has one single-axis and one dual-axis joystick, three pushbuttons and one three- way selector. Customised designs are also available.
Italian manufacturer Ravioli also emphasises compactness and lightness in its two new ranges, the Micro and the Dual. The Micro is again a dual speed pushbutton type of control which weighs only 500g. The Dual is 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 dual 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 into the new 868-870 MHz EC band, minimising the possibility of interference, Ikusi 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). 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 preventer 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 dual speed pushbutton models and five speed touch sensitive joystick units.
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 (PDA) to program 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 operation 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.
Crane and hoist producer KCI Konecranes has had this kind of feedback channel 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.
Factory and hoist control systems are increasingly using the ability of remote control units to take over, supplement or replace programmable logic control (PLC) functions.
Control Chief of the USA has recently installed a system at a hot dip galvanising works, for example, that works together with the PLC system and ties directly into the back plane of the PLC.