Think outside the box for cranes and hoists

When contemplating entering the cranes and hoists market, panel builders and system integrators need to think outside the box - not only laterally but vertically as well. Mainstream horizontal applications like conveyors cannot be shoehorned into the same category as cranes and hoists. Tony Young, owner and director of CP Automation explains the complexities of vertical lift applications.

Cranes and hoists is a specialised market requiring expertise in variable speed drives (VSDs) and inverters, programmable logic controllers (PLCs), motion control, braking, safety systems and last but not least, best practices.

The latter is important when working at height and systems integrators need to be fully insured when taking on this specialised environment. They need to be ISO-registered and carry out risk assessments on all crane installations.

If one considers moving a heavy object on the end of a length of cable, there are lots of complexities involved, like using anti-swing program software for example, when setting motion ramps and profiles in an inverter or PLC.

The systems integrator needs to make sure that whatever the weight of the object, the crane or hoist should not be stopped so suddenly that the object starts swinging back and forth to the point of losing control and causing potential damage as well as delaying the actual hoisting.

This is not the same thing as a soft start because the problem is one of controlling motion along several axes at the same time. For example, where a load needs to be lifted from a ship while the boom of the crane is also rotating, the load is swinging around and needs to be slowed down correctly to avoid the crane operator losing control of the load.

A crane's load suspended from a cable creates a pendulum that swings in motion. Anti-swing control calculates and compensates for this motion. The trade-off is between reducing load oscillations and transferring the load in a reasonable time.

Anti-swing software

In the past, before proprietary anti-swing software was available, this required considerable skill on the part of the crane operator. Controlling the load position and its swing may be implemented in a proportional derivative (PD) tracking controller to follow a prescribed trajectory.

Then, another controller may need to be added to the control loop to damp the load swing using techniques like time-delayed feedback of the load swing angle and an anti-swing fuzzy logic control. A mapping method used for generating the rules can be applied to mimic the performance of an expert crane operator.

Other functions may also need to be programmed in an IEC 61131-compliant PLC language like ladder diagram (LD).

By partnering up with electrical and automation companies, systems integrators and panel builders can increase their technical capabilities and understanding of the market. A good industrial automation supplier should be able to provide both in house and on site commissioning, servicing of inverters and ancillary products used for motors in cranes and hoists.

Systems integrators need to kit out workshops that are fully equipped to rapidly identify faults and components failures. They also need to employ experienced and highly trained engineers to provide both in-house and on-site services for all types of drives. Furthermore, they should offer a complete industrial electronic service.

Training instructors need to be industry experienced engineers with current hands-on application experience, whose technical skills are annually assessed and updated. They should provide a comprehensive selection of first class industrial automation training products, assessment services and courses to meet customers' changing needs.

So when designing panels for cranes and hoist applications, it pays to think outside the box. Go to www.cpaltd.net for further information.

CP Automation Ltd

Unit 8, Ashley Industrial Estate
Exmoor Avenue
Scunthorpe
DN15 8NJ
UNITED KINGDOM

+44 (0)1724 851515

enquiries@cpaltd.net

www.cpaltd.net

More technical articles
25 minutes ago
Last few places on Machinery Safety Course
Just a handful of places remain available on the last Pilz City & Guilds accredited Machinery Safety Course in 2020. Diary date is December 14th to 17th
3 hours ago
Camozzi Automation launches new quick exhaust safety valves
Designed to provide a plug and play solution for OEMs that need to be compliant with Machinery Directive 2006/42/EC, Camozzi Automation says that its new quick exhaust 2-way safety valve range also complies with ISO 13849-1 covering the safe design of control systems which perform safety functions
3 hours ago
SICK’s Open Service for IO-Link function blocks
A new open software service for control systems has been introduced by SICK
3 days ago
Automatic bearing lubrication brings ore inspiring results in mining
By installing automatic lubricators for bearings on its conveyor drive motors and belt pulleys, an opencast mine in Hungary has seen a range of benefits, including the prevention of unplanned downtime, longer bearing life and reduced repair work
3 days ago
Kinoulton company conveys COVID-combating masks
Here's a great example of the germ of an idea resulting in the combating of COVID
3 days ago
FLIR Systems announces four new Exx-Series handheld thermal imaging cameras
New E96, E86, E76 and E54 models feature enhanced thermal resolution and provide on-camera routing capability for more efficient inspections
4 days ago
New C-Mount lenses bring focus for machine and system builders
IDS now offers more than 20 new C-mount lenses with resolutions of 5, 8 and 10 MP as well as different focal lengths and optical classes
4 days ago
Backup DC motor for two rolling mill applications
Menzel Elektromotoren has built a replica of an old DC motor for a large German steel strip manufacturer
4 days ago
Distributed safety systems webinar 30th October 0930
In this webinar Pilz UK Product Manager David Collier will examine the state-of-the-art technology available to meet the demands of decentralisation
4 days ago
New narrow FeedThrough connectors save panel space
New from Cliff Electronics is the SLIMS FeedThrough Connector range, designed and manufactured in the UK