Earlier this year at the construction machinery trade fair Bauma, held in Munich, Germany, manufacturers of material handling products put forward their latest innovations.
Several demonstrated cranes that lifted loads without a wobble: developing sensors measuring height, weight, vibration and distance has been fundamental to this advance. Canadian manufacturer Cranesmart Systems supplies Caterpillar with the load monitoring system LMI 4 that provides the operator with load information, which Caterpillar says “significantly reduces the potential for costly and dangerous overloading, tip-overs and other jobsite accidents”.
Cranesmart LMI 4 uses a load pin, boom angle indicator, and level indicator, all integrated wirelessly into a central display panel. All the information from the sensors are displayed individually, leaving the decision-making in the hands of the operative.
Compiling information from separate sensors into something that automatically adjusts the crane’s jib means creating software. One of the earliest developments was by Italian crane manufacturer Fassi back in 2006. Its automatic dynamic control (ADC) limits the range of the crane articulations. A spokesperson says: “By increasing the movement applied on the crane and consequently of the pressures induced from the load in the lifting rams, a progressive reduction of the crane utilisation speed automatically occurs.
“This allows high speed movement without a load and with low-weight loads, with more controlled speeds with heavier loads. It means high operational safety in terms of truck stability and reduces the structural stresses on both the crane and truck chassis.”
Information from the sensors is sent to the software (or algorithm) situated in the main processor unit. Creating an algorithm is now the key for driving efficiency and safety with crane jib control, which stabilises loads and eliminates unwanted or irregular reactions created by sudden movement.
Within the fixed and bulk material handling sector, an algorithm for something that is aerial, like the crane jib, will be created from information sent by sensors, such as an accelerometer for movement and vibration, a gyroscope to measure and maintain orientation and angular velocity, a magnetometer for the direction, strength, or relative change of a magnetic field, and an altimeter for altitude.
For the position of an object on the ground, a global positioning system (GPS) receiver, where coordinates can be added, might well be included. Tolerances and countermeasures are added to the software package to create clear-cut stipulations for data processing, automated reasoning and calculation. Its end goal being to reduce the amount of unintentional movement caused by weight affected by acceleration and deceleration, as well as vertical and horizontal movement.
SPECIFIC ALGORITHMS
Like Coca-Cola and its secret formula, crane manufacturers do not reveal what ingredients go into their specific algorithms, however, the effect of each is to reduce unwanted movement that might render a load unsafe.
Last year, Palfinger introduced its Smart Boom Control (SBC) technology. Michael Völker, product manager for loader cranes at Palfinger, says that the driver for its development is the end-user. “The operator can choose the operating mode in the menu of the PALcom P7 radio remote control. With a single-button override function, the operator can even switch modes quite easily during operation. On top of that, different settings of SBC can be selected to exactly fit to the individual crane application, by prioritising a particular function.”
Underpinning it is an algorithm that calculates all the inputs from sensors and combines different crane functions into one movement, calculating movement using its position and pressure sensors. He explains: “SBC is a digital boom tip control for loader cranes, which enables crane operators to control a horizontal or vertical movement of the crane boom tip by using only a single lever.
“Any individual movement curve of the boom tip can be created, by combining only two levers. Crane models featuring TEC 7 technology are already prepared for this application. The operator can focus on the boom tip and does not have to think in separated functions like main boom up, or outer boom down.”
He says that less-experienced operators will benefit and can work much faster with the crane. “The intuitive way of operating will also prevent damage caused by lack of concentration. All the operator has to do is specify the direction of movement of the boom tip, while the electronic control system calculates the necessary movement combination, making cranes equipped with SBC easier to operate.”
Control of the boom, rather than crane jib or grab control, is central to the system developed by the manufacturer John Deere. It’s Intelligent Boom Control (IBC) was first developed for forestry forwarder machines in 2013 and then harvesters in 2017.
Information from sensors control the boom joint movements, leaving the vehicle’s operator to focus on the grapple when lifting logs. The IBC allows the operator to direct the reach and height of the boom tip parallel to the ground with a single lever moving the boom tip horizontally, and a second lever guiding it vertically.
HIAB also offers features aimed at helping operators ‘perform even better’. Among them are load stability systems for horizontal and vertical movements and Boom Deployment Assistant. More information and videos can be found on the HIAB website at www.is.gd/ajimiz.
STABILISATION
Outside of lift and shift, last year Eaton Hydraulics developed a boom stability control system. It can reduce the amount of hydraulic boom oscillation, or boom bounce, up to 75%, says Mike Rannow, engineering specialist for hydraulics at Eaton.
It uses a control algorithm and Eaton’s CMA mobile valves, which feature active damping technology using the valve’s onboard sensing and independent metering capabilities to detect vibration and automatically stabilise the entire boom structure.
The system includes counterbalance valves and manifold, pressure transducers, position controller, drive controller and hydraulic valves with information sent/received by wireless receivers to a remote-control device.
This is where the algorithm kicks in to stabilise a working boom, as well as reducing the boom settling time movement by up to 90%, Rannow says.
“Our boom stability technology delivers a whole new level of control; this technology has the potential to reduce labour costs, decrease component wear and maintenance downtime, and enable the use of lighter, less-costly boom structures,” he adds.