OUR NEW JOYSTICK TIMES 4
Our latest vehicle, the multi-talented PistenBully 100 4F, embodies the new PistenBully generation. And represents a completely new kind of operating concept, which includes the operator's entire workstation. The centrepiece of the new control panel, which is fully integrated in the armrest, is an innovatively designed 4-axis joystick, enabling the driver to control the blade intuitively with full freedom of movement with one hand.
Wanted: intuitively operated hydraulic controls
"For a long time, we have been investigating how we could make the complex control of the blade simpler with just one intuitively operated joystick", explains Klaus Frankenhauser, who is responsible for development of the driver's cab / moulded parts. "This plays a very important role when it comes to exporting our vehicles. In the USA especially, operators often stay for a season and only get a brief induction. So the simplest possible control is helpful." Admittedly - our requirements were high: the joystick had to be equipped with extra axes to ensure full reproduction of the blade's freedom of movement, and with control elements for acknowledging, adjusting and deploying other functions. Furthermore, we always have the highest standards at PistenBully in terms of robustness and reliability. And in addition to all that, we like a nice feel: ergonomic design of the handle piece, the adjustable position of the joystick - in brief: comfortable, fatigue-free work even during longer stints.
Found: electronics specialist for complex requirements
The search for the right partner was diffi cult - but ultimately very successful: RAFI from Ravensburg took over development of the innovative 4-axis joystick. There was a lot more behind this idea for us though: we will soon have a universal operating philosophy for all model series. The new joystick combines four axes for complete blade control and is based on different technologies: the joystick's xy setting enables the blade to move horizontally and vertically. In addition, the joystick grip can move in a similar way to a motorbike grip with an extra horizontal joint at the top, allowing the driver to adjust the tilt of the blade. The particular challenge lay in implementing an extra z-axis for control of the blade's transverse positioning. Strain gauges were integrated on the joystick's handle for this purpose, which tracklessly measure the deforming transverse forces. This ensures the operator always achieves the desired transverse position. "The demands on our Development department were high", reports Ulrich Riegger, Project Manager at RAFI. "On the one hand, they had to realise accurate control without interfering with axis motion. To achieve this the joystick's play, which is normally around 7/10 mm, was reduced to 7/100 mm - a major challenge for the series production." And of course at PistenBully we always insist on 100-% functionality from -40° to +80°.
Supple in the hand, flexible to control
The joystick grip needed to sit comfortably in the operator's hand, while also delivering good control of the many integrated buttons, rockers and rotary potentiometers. This has been impressively achieved: the joystick grip offers 18 control elements in all for rapid function selection, adjustment and input acknowledgement: The thumb fi eld is equipped with nine short-travel key switches, as well as three rocker buttons and three rotary potentiometers, which deliver an extended range of functions thanks to their double-click action. There are another three buttons on the back of the joystick and a rotary potentiometer to control with the index, middle and ring fi nger. The company conducted operability tests with lots of operators to start with, in order to achieve this complex range of controls without compromising on the optimum ergonomics of the perfect design.
The first of its kind
The joystick on the PistenBully 100 4F has now been put to the acid test and has already impressed lots of drivers. The new control panel will supersede the existing operating philosophy in the future for all other model series, simplifying tool handling and contributing to a universal look & feel in vehicle cockpits, promises Klaus Frankenhauser: "We have been working for a long time on a pioneering, comfortable operating concept to be installed universally across all vehicles, and have invested a lot of time and money in doing that. With this unique joystick we have succeeded."