ELECTRONICS KEEP YOUR DISTANCE A NEW SERIES OF USER-FRIENDLY RADIO REMOTE CONTROLS ENABLES THE SAFE AND EFFICIENT OPERATION OF MACHINES IN TOUGH OR DANGEROUS ENVIRONMENTS. A CLOSE CO-OPERATION WITH A MANUFACTURER OF MOWING MACHINES LED TO PARTICULARLY NOTEWORTHY RESULTS The FJM layout for the Robogreen mower makes remote control easy and intuitive With the launch and development of Autec’s Dynamic series of safety remote controls, the electronics specialist has expanded its target application fields by providing completely flexible and adaptable solutions. One example of its recent successful case histories involves a tracked, radio remote-controlled mower from Energreen, an Italian manufacturer of innovative mowers. The Robogreen model is used for the maintenance of areas such as motorway embankments, roundabouts and steep river banks that would be too tough or dangerous for an operator to tackle. It offers high stability even on difficult terrain (slopes up to 55°) due to its highgrip tracks, as well as power and precision through a wide range of available flails and attachments. The machine is completed with a user-friendly radio remote control that enables excellent manoeuvrability. Its intuitive finger-tip commands make it even easier to control its direction and movements, ensuring operation from a safe distance (up to 100m working range). 140 iVT International Off-Highway 2013 The FJM radio remote control The radio remote control chosen to control the Robogreen mower is an FJM transmitting unit combined with an ARM receiving unit. The configuration of the transmitter has been specifically engineered to respond to the specific requirements and needs of the application. The system’s main actuators are two dual-axis joysticks, two potentiometers and several switches (see main image, above). The layout has been designed so as to make using the radio remote control easy and intuitive. This remains the case even if different equipment is mounted, as the commands have been studied so that they can be easily adapted to each tool. The left joystick is a proportional controller that is used to move the mower forwards and backwards. This joystick also controls the machine’s groundspeed (up to 7km/h), whereas the upper potentiometer acts as a sort of analogue speed selector, setting the maximum speed in a 0-100% range. This way, operators can customise speed to match their personal preferences. The right joystick, used in combination with the left one, is used for steering the Robogreen. On the other hand, if that joystick alone is completely moved to the left or to the right, the mower performs counter-rotation. The y-axis is used to move the flail head up and down. The lower potentiometer is used for steer control. When working on sloping meadows or steep banks, the speed of a track can be changed in relation to the other. This way, any downhill slipping due to gravity can be neutralised by reducing the speed of the upper track, so that the machine maintains a straight direction. Several switches and pushbuttons are also available on the radio remote control, which are used for the operation of attachments or for auxiliary functions. Operators can also control the engine’s functions and perform the start-up and switch-off of the machine directly from the remote control system, as well as adjusting the engine’s rpm. The ARM receiving unit is a DCsupplied receiver that provides up to 12 ELECTRONICS DANIELE OLIVIERO & CHIARA RIGHELE Dynamic series technical data at a glance Robogreen mower working at the Mugello Formula 1 racing track analogue and up to 64 digital functions. Digital, analogue and serial inputs are also available. ARM can also be integrated in a CANopen network, so that the receiver can communicate with the machine controller (if present), or collect data from the machine. Such data is then shown on a graphic display on the transmitting unit. ARM outputs are designed to be programmed to meet the machine’s exact requirements. For instance, timed and pulse functions, as well as logical functions (e.g. preventing movements if an opposite movement is active) can be obtained with proper programming. Possible future developments Autec is now working with the machine’s manufacturer to develop an improved solution to control the Robogreen. The Dynamic series CRS receiver will be used in place of the ARM – this is considerably smaller than ARM because all controls are sent via the CAN network. Furthermore, it can easily communicate with an electronic control unit that will be integrated on the machine to completely manage the machine functions. Engine management (which is currently performed through separate electronics) will also be carried out by the same ECU. The transmitting unit will also be replaced by the new FJR model, which features marginally more compact dimensions, providing further advantages in ergonomy and usability. The special features that have been implemented in this application are the result of a process involving different players, both on Autec’s side and on Energreen’s side. Intense cooperation between Autec’s engineering unit and the manufacturers and suppliers of the main components of the machine (such as the hydraulic banks, hydraulic pump and engine) helped provide a tailored solution responding to the requirements. Autec’s R&D department was involved in defining and designing the system’s firmware to manage the track control, whereas the configuration unit was engaged to define the most suitable transmitter layout (to meet the customer’s needs) and the receiver’s characteristics. This exemplary teamwork led to several improvements, proving that optimal results can be reached whenever the Dynamic series ARM, ARS and CRS receivers (from left to right) Frequency bands: 863-870MHz / 915-928MHz/430-470MHz (up to 256 available channels); Typical operating range: 100m; Number of proportional commands: Up to 12 (+16 digital commands for direction); Number of digital commands: Up to 64; Commands typical response time: <80ms; Safety category for the Stop protection: PL e, cat. 4/SIL 3; Safety category for the protection against unintended movement from standstill (UMFS): PL d, cat. 3/SIL 2; Autonomy with fully charged battery: Up to 11 hours; Operating temperature range: -25° to + 70°C; Receiving unit power supply: 8-30V DC. relationship between OEM and customer starts out with the analysis of specific requirements, and proceeds with fruitful cooperation on both sides. The Dynamic series at a glance FJM is just one of the transmitters belonging to Autec’s leading range of products: the Dynamic series for mobile hydraulic machines. The series is certified for functional safety by TÜV SÜD. For example, the Stop function complies with the requirements of EN ISO 13849-1 Performance Level ‘e’, Cat. 4 and EN IEC 62061 Safety Integrity Level 3, while the UMFS function (which protects actuators against unintended movement from standstill) provides PL ‘d’, Cat. 3/SIL2. The Dynamic series has recently been expanded with the introduction of the new ARS receiver and FJR transmitter. ARS combines the CAN interface with some of the features of an analogue receiver in a compact casing, particularly designed for installation on vehicles. The FJR transmitter boasts compact dimensions, while also offering excellent configuration options. This makes the transmitter the ideal solution for machines such as concrete pumps, telehandlers, mid-size MEWPs, or autonomous vehicles. A new, transflective graphic display that offers optimised visibility for outdoor usage is also available in the Dynamic series of transmitters. iVT Daniele Oliviero is application engineer for mobile hydraulics at Autec Safety Remote Control; Chiara Righele works in Autec’s marketing department CONTACT www.autecsafety.com info@autecsafety.com iVT International Off-Highway 2013 141
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