Knowledge is power

Traditional remote control interfaces offer a clear and simple way of directing a crane’s movements from a distance. For many applications, this will be sufficient. However, where more complex control is needed, or where an operator needs to receive detailed feedback on a crane’s state while working, other solutions must be found.

Graphic, LCD-based, displays can improve the functionality of remote controls in two key ways. Firstly, a series of displays can be used alongside buttons, to indicate the button’s function in a multimodal system. In traditional systems, an operator would have to remember the function of each lever every time he changed modes. In graphic display systems, the mode of operation and the function of each lever is displayed automatically.

The ability of displays to make controller function explicit within a multi-modal system is not merely a matter of operator convenience, but of regulatory compliance. The EU Machinery Directive’s requirement 1.2.2, for example, insists that:

Where a control is designed and constructed to perform several different actions, namely where there is no one-to-one correspondence (e.g. keyboards, etc.) the action to be performed must be clearly displayed.

Secondly, systems with displays of this sort can also incorporate complex two way communication systems, updating the remote’s display with data from LMIs, outriggers load sensors, or any other system, in real time.

Alan Johnson, departing chairman of ALLMI (the UK Association of Lorry Loader Manufacturers and Importers) and MD of onsite service company SJB Crane Co, explained why this feedback can be so important: “I’d draw a parallel with feedback displays on cars – by keeping drivers informed of petrol usage, for example, these encourage better driving. In the same way, feedback on crane remotes encourages better operation.

“Displays enable operators to understand the geometry of the crane’s boom system. By seeing that, for example, the inner boom is at 85% capacity while the outer boom is only at 50% capacity, you can see how to optimise the boom configuration. The obvious benefit to this is that it reduces stress and strain on the system.

“For retailers in the building trade, safety and user friendliness is the key attraction. Using a remote means you can be where you need to be, not on the vehicle. This is both safer, in the event of the vehicle tipping, and more convenient in that you can be at the loading point, particularly useful when loading or unloading in difficult locations.”

Olsbergs MultiDrive

Olsbergs’ new MultiDrive system combines both of these benefits. A central screen carries feedback information from the crane’s system and details of the function menu currently being used. Two additional screens, mounted on either side of the central display, and above the remote’s six levers, display the current function of each lever as icons or as text.

The system has seen its first commercial implementation in Hiab’s new CombiDrive2, and Olsbergs are working with other crane manufacturers to integrate the MultiDrive with their products. Jan-Erik Steen, Olsbergs Electronics MD, explained, “The controller is completely new. It connects via an interface to the crane’s safety system, which is made by Hiab as part of their Space system of sensors.”

The key selling point for Olsbergs is the clarity of the product’s multi-menu display. Olsbergs claims that the MultiDrive’s ability to display changing modes of operation immediately within a multi-modal system, makes the controller functions uniquely clear.

In the Hiab implementation, marketed as the CombiDrive2, the menu system uses three top-level menus:Crane, Extra and On/off. The first of these menus, Crane, controls crane functions. Sub-menus are set up when the control is fitted to the crane. The second, Extra, controls functions on the vehicle other than the crane, such as stabilisers, boat support and bunk shifting. The final top-level menu lets the operator control on/off functions, such as starting the engine or switching off vehicle lights – Hiab suggests 12 such functions, but Olsbergs points out that the number of functions that the MultiDrive system can use is unlimited.

Operators can program the remote’s menu system and the function of each lever in each menu in the workshop, using Hiab’s SPACE software. From the three main menus, an unlimited number of sub-menus can be set up, although Hiab recommends that three sub-menus per top-level menu are most practical.

Leif Tornbolm, Hiab product manager, explained some of the advantages of using a graphic display. “In the old CombiDrive system, if the customer switched menus, they would have to remember what each lever’s function was. With the display, this isn’t an issue. The crane feedback display is a lot safer – it means that in tricky situations an operator can work at close to the crane’s capacity more easily, without risking triggering the overload protection system.”

Jan-Erik Steen points out that the potential for displaying feedback information on the MultiDrive is virtually limitless: “It’s easy to connect to CAN systems. In future, we’re looking at displaying information on oil pressure and temperature, the amount of gas in the vehicle’s tank, or whatever else the end users want. It can receive any sort of feedback from the truck, so you could even show the dashboard on the display.”

Datek

Datek launched its own graphic display system for its D2801 MIDI system in late 2005. The company has focussed on the ability of graphic displays to provide complex feedback information to operators of electric overhead travelling cranes in a clear fashion. To make use of this, the control needed a two-way communication system.

Martin Westerling, Datek sales manager, explains, “We work a lot with Konecranes in Finland. Unlike most of the EU, customers there need to buy licences for the radio spectrum they use. If we’d used a full dual frequency system [with the crane and the remote transmitting on separate frequencies] the customers would have had to buy more licenses, and would have more quickly run out of space in the radio spectrum.

“Instead, we used a semi-duplex system. In this, transmissions from remote to crane, and crane to remote, are interrupted on a timed basis. So, while the crane is sending feedback information the remote is momentarily switched off, and vice versa.”

The remote can display information from a huge number of sources. One Datek customer, working at a Danish harbour, has set up their remotes to respond to more than 150 different alarms. Each alarm message is ranked according to priority, and displayed to the operator in order of importance, making it easier to know which is most urgent.

Datek is also looking at developing multi-modal functions for the remote. It is applying the remote control technology to cranes using magnetic grabs. In these, up to fifty separate magnets may need to be turned on and off individually, depending on the load to be lifted. To accomplish this with traditional technology, a remote control would need a bulky unit with toggles for each magnet.

In Datek’s system, all of the magnets can be displayed on the screen at once in an x/y chart, showing their on/off state. The operator can move through the magnets, toggling them as needed. Once a pattern of magnets has been chosen, the operator can store this, and use it again later.

Ikusi – LCD 70

Ikusi’s range of tower, mobile and overhead crane remotes can all be fitted with an optional graphic display. The company’s console box type 3 and 4 remote systems for tower cranes and mobiles feature joystick controls and a 120×80 LCD graphic display.

The system’s flexible receiver can be integrated with the rest of the crane’s electronic systems, using analog and digital signals, and the CANbus controller system. The display can show the operator feedback information and range of alarm signals, to warn of hazardous movements or overloads. In tower or mobile crane applications, the display can show information such as load weight, wind speed, and load height.

The system can be set to respond to different alerts on each job. Users can choose to display information using graphical objects or text – José Ramón Elustondo Iriarte, remote control product manager, pointed out that the system can even using non-Latin fonts such as Chinese. As well showing feedback information, the display can also be used to help with configuring the remote and its radio system prior to starting a job.

Hetronic – Nova XL

Hetronic’s Nova XL remote control system can be configured with a choice of up to four joysticks or eight paddle levers. The system is sold in a variety of pre-engineered off-the-shelf solutions for common applications, but can also be customised for specific users.

The large remote console has space for a graphic display, showing text or graphical objects. Feedback can be sent from the crane using CANbus, Profi Bus, RS 232, 0-10V dc or 4-20mA signals. Information can be taken from any of a crane’s sensors, and the display can also show control functions as an additional aid to the operator.

Markus Haas, Hetronic export manager, comments, “The graphic display is becoming a common tool for truck loader cranes, tower cranes and self-erectors. Crane manufacturers are using the system to display information coming from the hook, trolley, boom, and load sensors. The system can indicate wind speed, to let the operator know when this is becoming too high and it would be dangerous to continue work.”

Haas explained that the display adds reliability. For example, an operator may ask: “‘How far is my trolley out? 15m or 17m?’ With the read-out on the display you can be sure. This is adding to safety in operation, not just convenience or efficiency. The graphic display is an option that enhances the accuracy of any machine operation.”

HBC Radiomatic – Micron 6

HBC Radiomatic’s handheld Micron 6 controller offers clear multi-functional controls using the company’s iCON (intelligent control) display system. The display gives the user access to a wide range of system-specific data. Alex Hemming, HBC Radiomatic product manager, explained that this feedback can include both analogue data such as load weight or hook clearance, or digital data on overload, limit switch or oil pressure.

The iCON system makes use of so-called graphical softkeys displayed on the screen. Users can scroll through and select softkeys by rotating or pressing two push-buttons. Customers can access controls to configure the remote’s interface to each users needs, creating their own icons on the display or setting specific early warning points for overload protection.

These settings can then be saved to the transmitter, and changed as needed. As settings are stored on the transmitter, they can be quickly restored if the remote console needs to be replaced. User groups and permission levels can be configured using the system, and protected with pin codes. This means that specific system functions can be restricted to particular users.

More integration ahead?

In the past, remotes have been particularly popular in Scandinavian markets, with some sources suggesting that up to 80% of cranes sold in the region carry remotes. However, they now seem to be of increasing importance in other regions, such as the UK. Here, sales had stood at around 5% of cranes sold.

However, some of the country’s leading sales channels are now moving over to requesting remotes fitted to their cranes. At the same time the top five lorry-loader manufacturers selling in the UK, and taking part in ALLMI’s new market share statistic scheme (see news pages, this issue) have requested information on remote sales – a clear sign of the increasing importance of remotes to this market.

Using remotes does incur costs – around 5% on the initial outlay for a lorry-loader. It also requires training of operators. As Alan Johnson explains, “Operator training is always a fine balance between equipment familiarity training, from the vendor, and general training through certification. At the moment this is a new technology in the UK, so it’s a question of familiarity training, not yet certification, but as the popularity of these systems grows, it may become so.”

It remains to be seen whether remote systems will become as uniform in the UK, and worldwide, as they are in some markets. Remote systems may add to initial purchase and training costs: however, the increased benefits of safety and convenience, along with reduced ongoing expenses through improved operational efficiency may justify this to many end users.