Kontrollarm

Kontrollarm is a mechanical linkage used in various engineering applications to transmit motion or forces while constraining movement to a defined path. The term is common in Swedish and Norwegian engineering literature and is often translated as control arm in English.

In automotive engineering, a kontrollarm is a suspension linkage that connects a wheel hub to the vehicle frame or subframe. It functions as a pivot and supports loads, helping to maintain wheel alignment and contact with the road. Vehicles typically have upper and lower control arms, or a single control arm in MacPherson-strut designs. Control arms accommodate bushings and ball joints to allow limited angular motion while absorbing road shocks. They are usually made from stamped steel, forged aluminum, or composite materials, selected for strength, stiffness, and weight.

In robotics or machinery, a kontrollarm may denote a rigid linkage in a robotic arm that transfers motion from actuators to the end effector. Such arms can be serial chains of links connected by rotary or prismatic joints, or part of a parallel linkage. The design determines reach, stiffness, payload, and kinematic behavior; control systems compute joint angles or displacements to achieve desired end-effector position.

Maintenance considerations include wear of joints or bushings, corrosion, and fatigue; inspection for cracks, lubrication of joints, and realignment after impacts or repairs. In automobiles, improper control arm wear can affect steering, handling, and tire wear, and damaged arms should be replaced in matched pairs to preserve alignment.