Inverted 3-Arm Pendulum - Complex Control System Pendulum systems allow scientific investigations of control algorithms at a complex mechanic system. Further on they will be used in trainings of students.   An inverted pendulum is located at a horizontal mobile carriage. The pendulum will be positioned by the movement of the carriage using a multiphase motor and appropriate control algorithm. One feature of the system, produced by HASOMED, presents the ability to swing a single or double pendulum from rest to an inverted position and balancing of a 3-arm pendulum. The 3-arm pendulum has been developed in cooperation with Prof. Gilles, Max-Planck Institute Magdeburg, and HASOMED, and is worldwide only produced by HASOMED.

Mechanics   Solid construction, 2450 (length) x 1200 (height) x 450 mm, built of aluminium and heavy granite plates (first figure – please click to scale up) in order to avoid external disturbances to controlled arms.   Linear auf einer Schiene bewegter Wagen mit Ankopplung zum ersten Pendelarm eines einfachen bzw. doppelten Pendelsystems. Optionale Erweiterung auf ein System mit 3 Pendeln - 3-fach Pendelsystem. Linear trailed carriage with connection to the first pendulum arm of a single or double system. Optional extension to a system with 3 pendulums – 3-arm pendulum system. The carriage (third figure) moves over a guide rail with a distance of max. 1900 mm.   Following pendulums belong to the standard delivery package of a 3-arm pendulum:   1. Pendulum with a length of 800 mm as a standard pendulum (other sizes available) without connection to a second pendulum.1. Pendel (siehe zweite Abbildung): Länge 320 mm mit Ankopplung zum 2. Pendel. 2. Pendulum (second figure): length 320 mm with connection to a second pendulum.3. Pendel mit einer Länge von 450 mm. Pendulum with a length of 420 mm with connection to a third pendulum. Pendulum with a length of 450 mm.

	Control unit, servo control, electric power supply for pendulum in a separate box (Linux PC and Interface ME2600).
	The movement is electrically limited by automatic limit switches and is secured by buffers with dashpots
	Actuation of the carriage by a servo motor (700 watts). The position of the carriage is measured by a sensor on the axis of the motor with 8192 puls/rpm
	Electric power supply of the pendulum’s electronics (angular transmitter) by accumulators inside the pendulum (charging by delivered mains adapters)
	Switch for recognition of the carriage´s middle position, e.g. for starting the experiment (detectable by the software).
	Switch for starting the program (put out about software as well).

The construction of control algorithms happens via the standard software “Mathlab”. The control algorithm is transmitted, e.g. via network, to the controlling PC (Linux). The software on the Linux PC then takes over the control of the pendulum. All angles of the pendulums and the carriages are measured by incremental sensors with a resolution of 8.192 puls/rpm. A description of the hardware interface allows individual trial requirements via control software, generated by the user.

The 3-Arm-Pendulum is in use in the Max-Planck Institutes in Magdeburg and Stuttgart. Further references are the University of Magdeburg (Prof. Raisch) as well as the University of Karlsruhe (Mr Boehringer). In Karlsruhe even two pendulums are in use for a practical training.