Cranes: longer booms, lighter steel, load sway old control misses

The structure flexes and sways; the old controller no longer copes

What happens. New crane generations have longer booms and lighter steel. The structure bends under load and vibrates after every move, and the load swings below it. The control that worked on the stiffer predecessor now leaves the operator to wait until things calm down.

What it costs. Cycle time, because every lift ends with waiting, and safety, because a swinging load near people or structures is a risk. Customers notice when the new, bigger crane is slower than the old one.

Why the usual fix fails. Slower ramps and softer settings damp the motion but give back the speed the longer boom was meant to deliver. A tuning that works for one boom length and load is wrong for the next, and a filter tuned by hand cannot know the real flexible modes.

How a fixed-price remote diagnosis checks it. From drive and encoder logs, load and angle signals and what you know of the structure, I check which flexible modes dominate and whether sway can be computed from signals you already have. The fixed-price remote diagnosis tells you whether a flexible-structure model with sway and vibration control is realistic, and what measurements it would need.

Background: Robots and machine tools: path accuracy

Loads swing on warehouse and bridge cranes

What happens. A bridge or gantry crane accelerates, and the load swings like a pendulum. The operator, or the automatic system, waits for it to die down before lowering, or sets down gently and slowly to be safe. The faster the crane drives, the worse the swing.

What it costs. Cycle time on every move, and with it throughput of the warehouse or hall. Swinging loads also put wear on ropes and drives and raise the risk of hitting racks and people.

Why the usual fix fails. Lower speeds and longer waits are the common answer. A sway sensor on every hoist adds cost and a part that must be maintained, and a fixed input shaper is tuned for one rope length and one load, while real rope lengths change with every lift.

How a fixed-price remote diagnosis checks it. From travel, hoist and drive logs of a typical working day, and the rope lengths and loads you handle, I look at how large the sway really is and whether it can be estimated from drive signals alone. The fixed-price remote diagnosis tells you whether sway estimation and control can shorten your cycles, and what it would take.

Crane control software is tested late, on the real crane

What happens. The control software is written and then tried on the crane, in the yard or at the customer. Faults in the interplay of drives, safety functions and load logic show up only then, when a change is slow and expensive to make.

What it costs. Commissioning time, repeat visits and risk to people and equipment while the software is still being proven. Engineers who could improve the control spend their time on trials and on waiting for the crane to be free.

Why the usual fix fails. A crane model that is only used for one purpose rarely matches the real machine. Extra test days on site help, but are slow, depend on weather, and cannot safely try the dangerous cases.

How a fixed-price remote diagnosis checks it. From your control structure, interface list, test reports and what is measured on the real crane, I check how detailed a simulation model must be to test the software before the crane exists, and which cases belong in a simulation and which on the crane. The fixed-price remote diagnosis gives you a plan for testing with models in the loop, and what it takes to build one.