Evolution of safety

29 April 2016


As crane control systems have become more sophisticated so have the remote controls that operate them, with ergonomics and display innovations a major focus.

Remote controls for truck mounted knuckleboom cranes have certainly come a long way since they were first introduced thirty years ago.

"When we introduced them in the late 1980s they were considered something exotic for very special customers. But with the machine directive of 1995 it became obvious that all crane manufacturers would develop electronic safety systems so the electronics on the crane evolved together with the radio remote systems and melded more and more together," explains René Dalkhilde, product manager for crane manufacturer HMF Group A/S.

HMF patented its electronic control unit RCL (rated capacity limitator) in the mid 1990s starting with the 5100 model, which was then upgraded to the 5200 and the 5300. "It is now very integrated to the radio remote systems. The advantage was that you could put one man out to do a two man job because you can attach the loads when you had the remote and be in the right position and it has become more and more common on more and more cranes," says Dalkhilde.

Another major advantage of the new electronic control systems was the ability to slow down the crane movement, which allowed more effective use of the crane at greater capacities because dynamic loading was reduced. "You can now control the movement of the crane in a way that means you can allow it the same steel construction crane with the same weight to lift something more - so you can make an advanced model with maybe a pressure of 350 bars on this electronic version with a radio control unit compared to 300 bar for manually operated crane," explains Dalkhilde.

"So there was a lot of physical and economic advantage of using this integration."

Electronic control systems and radio communications systems have therefore developed in parallel for the past two decades with crane manufacturers often designing the electronics and subcontracting out the hardware to subcontractors. HMF for example has worked with Swedish radio remote control specialists Scanreco. "We buy the radio control units from outside but we make the electronics ourselves. Almost 4 out of 5 cranes in our production come with radio remotes today," says Dalkhilde explaining that the RCS range is the most popular of the company's four groups of loader cranes - the MC, MCS, RC and RCS.

One of the areas where HMF has focussed a lot of effort is on trying to reduce the number of components in its remote controls. "We are now more or less full CAN bus control all over the crane that means we are saving on wiring and these items and the valve blocks we are using this CAN bus system and that is the way we are trying to develop - by reducing complexity. We are trying always to do it better than the years before."

All communication options are included on the radio control unit for HMF loader cranes. "This means we have 8 hydraulic on/off functions directly on the display. Then we have some switch modes so another 8 functions so that is 16 hydraulic functions. Then we have up to 5 digital on/off functions that can be operated from the panel. So that means 21 functions that can be operated.

We thought that would satisfy the users but people are still asking for even more functions!"

In 2002 the company patented its HMF info centre, which at the time was a new kind of display using numbers and graphics. "Today it is very normal for people to use a smart phone or tablet display to read what is happening but in 2002 this was more or less a sensation.

Our competitors had diode LED lights with green or red or yellow. But we put this display on so they could read out useful information, i.e. in percentage how much were the cranes loaded ect. We can use it when we operate stabilisers and the HMF InfoCenter can be programmed and adapted to each individual crane operator."

System evolution

Load handling equipment specialists Hiab too began with a basic system that soon evolved. "Our first remote control was launched in 1985. In the early days remote control was connected with a cable and the diameter of that cable was rather thick and not easy to work with," says Marcus Rosth, manager of control systems for loader cranes at Hiab. But by 1991 the firm introduced its first radio remote control, the first generation CombiDrive, which today is on its third generation. "CombiDrive is considered to be a remote control for high end series, high performance cranes. In 1992 we introduced it with the first control system where we used sensors to enhance some functionalities and safety features to prevent making unsafe movements with the crane. We had overload detection ahead of the 1995 legislation," says Lennart Andersson, system manager crane controls and product management for loader cranes at Hiab.

Displays on the remote control were included on the second generation CombiDrive. "There are three displays, one main display showing the menu. Apart from this there were displays for every lever so when you switch from one to another each lever changes function so in the display you have a dynamic representation of what that lever is doing right now. There is a symbol indicator for every lever and that is unique in the market place," says Andersson.

The thinking behind this was that it would make it easier for the operator to keep track of the operations underway. "If you have several menus suddenly it has to be complicated to remember what the lever will do so the thinking was to have a small display for each telling what this actually means in this menu. We know that we are still unique on that today. With Combidrive 2 we had the option to use 8 levers instead of just 6."

On the next generation Combidrive, Combidrive 3 the company has further improved the display to give more information on the features and improve feedback. Of course it also includes the latest iteration of the stability control system, the VSL+ "The stability diagram and chart is shown in the display during driving so that you can see what stability you have and the VSL+ which was released in late 2015 is a unique function where the stability is changing due to load," says Rosth. VSL+ was launched in Autumn 2015 and will be available on more crane models at Bauma.

CombiDrive is not the company's only remote control for loader cranes however. In 1999 the firm introduced a product for the lower end of the product range RadioDrive.

"RadioDrive didn't have feedback it was more manual buttons and was a 6 lever remote control," says Andersson. By 2005 the company introduced its XSDrive controller which introduced driver feedback with capacity overload indication.

"We also had to use different menus so that you had different modes for the controller. We were the first making a hand controller purely for load handling working with the crane," says Rosth.

A particular focus of the XSDrive was that it concentrated on ergonomics and the driver. It therefore came with a variety of carrying options including belt, neck strap and a body harness. "It has been very well received and we have sold a big number of these radio remote control systems," says Rosth. More recently in 2014 this remote control was launched alongside the X series of cranes with joystick possibilities.

Although originally aimed at lower specification cranes the XSDrive can be used across the product lines Ergonomic design Ergonomics has also been a key focus for Germany's HBC-radiomatic which offers a wide range of radio receivers in different housing sizes with direct valve control and all common interfaces for bus connection. "Our transmitters today are much lighter, more compact and more manageable than 20 years ago," says Alexander Hemming, head of product management, HBC-radiomatic GmbH. "We have categorically enhanced and improved all HBC controls with regards to ergonomics as well as developed additional new products with an exceptionally ergonomic design, such as our technos series.

New battery technology means that the firm has been able to considerably increase the operating times of its loader crane controls.

"Currently we have switched a whole set of HBC radio controls to Li-ion technology, and others will follow shortly," says Hemming.

Frequency management has also been a key area of development across the industry. Since loader cranes are frequently operated in different areas, there is the potential for frequency conflicts with other radio users. "With the development and introduction of intelligent and automatic frequency management procedures, such as radiomatic® AFM (Automatic Frequency Management) and 2.4 GHz technology, we have an efficient solution available," says Hemming.

Of course the firm has also been updating its display technology too with the loader crane controls being systematically updated parallel to the development of display technology for consumer products. "For our receivers we kept close track of the technical development of loader cranes and implemented many different serial interfaces. As of today, we offer virtually all possibilities for a direct valve control and have all common serial interfaces with diverse protocols in our portfolio," says Hemming.

Italian remote control company IMET also has a range of remote controls for loader cranes. The compact KRON controller is for 4-function cranes, the ZEUS2 covers the 5 to7-function cranes, while the THOR2 is recommended for the control of big 8 or 9-function cranes.

"The new housings combine robustness, ergonomics and resistance to all types of working environments; in fact, we declare IP65 protection degree and -25°C to 70°C working temperature range," says Bruno Da Re, export sales manager, IMET.

The single and dual axis joysticks, fully designed and manufactured by IMET, are based on Optical Sensing Technology and come with a wide +/- 40° lever stroke allowing a very precise control of the movements. De Re explains that several options are available as well, like data feedback screens for displaying crane status information; cable connection between the transmitter and the receiver to by-pass the radio frequency link; DSC (Dynamic Speed Control) for the real time adjustment of the motion speeds and the automatic frequency change, for trouble-free operation in job sites where many radio-controlled machines are present. "Practically, we offer an unlimited command capability, together with bidirectional radio transmission, graphic displays, automatic frequency management and the highest functional safety categories available," says Da Re.

Multiple configuration options Spanish electronics firm Ikusi says that as the knuckleboom is one of the main applications for the mobile industry the firm has taken this into account when developing its products and specific functionalities, in order to satisfy the needs and requirements of the users. Raul Martin, Product Manager in Ikusi Remote Control, explains how the company has developed ad hoc specific characteristics so as to update its remote control technology in this area. "The medium size transmitter of the Ikontrol family has a perfect configuration to handle these type of machines. It brings multiple configuration opportunities, such as the 3 axis joystick or the paddles, which allow the perfect synchronization with the movements of the knuckleboom truck," he says.

This type of console box can include a TFT (thin film transistor) colour display which enables machine feedback. "Thanks to the CANOpen feedback, we can visualize the information from a PLC (programmable logic controller)," says Martin who adds that the text format information is shown in 4x20 characters, with or without LEDs, or in 2x10 characters with LEDs. The new display also offers the possibility to present the information graphically, by using different icons, available in several formats.

Martin explains that the benefits from the system are: Increment potential visualization formats; users can get a higher degree of customization (for example feedback shown in the display can be adapted to the machinery); and the information is user-friendly.

The feedback software is also in constant evolution: "The information shown in the first software version was limited in space and in the Graphic resources. Nowadays, this feedback has turned into a dynamic environment where the user can customize the configuration of the machine's feedback, according their preferences and requirements," says Martin.

This is a key area where manufacturers of cranes and remote controls alike are expected to focus their attention. "Our new color displays are among our major innovations. Not only do they allow different customized configurations for the indication of machine data, but also the connection of video cameras that can be installed anywhere on the loader crane," says HBC-radiomatic's Hemming. "Using our newly developed radiomatic® photon, the operator can see live camera images directly on the control and is thus able to control the machine precisely and safely even in areas without a direct view on the working area."

HMF agrees this is an important area "Communication with the operator is an ongoing project and the development into different screens and colours and TVs and cameras, communication with telephones, will still be a very big focus for talking to the operator," says Dalkhlide. "Every engineer's dream is to get these screens with high lights emitting screen and you can write messages and so on but too much information is not good so it is based on necessity.

That should be the focus. We have to help the operator in the best possible way because there is so much he needs to attend to."

Safety first

On the safety side Dalkhilde warns of a couple of issues that the working group for EN 12999, the European loader crane norm, are considering. "One of the latest things that is coming out and is on vote here, is the means to ensure that the truck is not in gear if you can start it from the remote control. It much be in neutral. There have been some serious accidents in Germany so everyone has to pay attention."

At the same time he notes that new dangers can occur related to the remote control if the emergency stop has not been pressed and this is something that must be done when cranes are not in use. "The radio remote is here to stay so it is up to us to integrate it in a good and safe way and we still keep it simple because one has to be very aware of the complexity of the tasks facing the operator."

HMF’s RCL 5300
An operator controlling an HMF crane with a remote control
IMET’s radio remote controls
Hiab’s CombiDrive 3
Using Ikusi’s IK3
HBC-radiomatic’s Technos 2
Hiab’s XSDrive with joysticks