# Active Mass Damper

## Control Vibrations in Tall Building-like Structures

The Quanser Active Mass Damper (AMD) is a bench-scale model of a tall building instrumented with an accelerometer. It is ideal to study control techniques used to suppress vibrations in tall buildings. The AMD experiment is available in 1 floor or 2 floors configurations. Students learn how to:

• model the linear servo plant from first principles to obtain open-loop transfer function
• design a proportional-velocity (PV) position controller to drive the active mass and cause vibrations of the flexible structure
• model the AMD plant using the Lagrange method and obtain its state-space representation
• design and tune a state-feedback controller strategy to dampen oscillations of the structure
• implement the mode-switching control scheme on the AMD system and observe its performance

In addition to teaching control concepts, the Active Mass Damper can be used for research in various areas, including acceleration feedback and Linear Quadratic Gaussian control.

## Create a Configuration That Suits your Needs

The AMD structure with 1 or 2 floors can be used as a stand-alone system. You can also use several one-storey AMD structures in series or parallel configuration. Moreover, you can use the AMDs as an add on structure for any of Quanser Shake Tables and create different MIMO experiments.

How It Works

The One Floor Active Mass Damper plant consists of a single-story building-like structure with a controllable linear cart (i.e. active mass) on the top. The cart is driven by a high quality DC motor through a rack and pinion mechanism and is free to move along in the same direction as the structure. The AMD frame is made of steel and is flexible along its facade. The top floor is instrumented with an accelerometer to measure the acceleration of the “roof” relative to the ground.

The cart position is directly measured using an encoder. The encoder shaft meshes with the track via an additional pinion. Two masses can be attached to the cart to increase its inertia to absorb vibrations of the structure. The masses can be used individually, together or can be removed to assess the robustness of the controller and effects of variations in parameters.

In the Two Floors AMD configuration, the plant consists of a two-storey building-like structure with a controllable linear cart (i.e. active mass) on the top. Both floors are instrumented with accelerometers measuring the acceleration of the middle and top floors relative to ground.

## Quanser-developed Courseware Included

The AMD 1 and 2 floors experiments come with Quanser-developed courseware. The workbook with practical exercises, together a comprehensive User Manual, pre-designed controllers and a dynamic model allow you to get your lab running faster, saving months of time typically required to develop lab materials.

• High quality DC servo motor and gearbox
• High-resolution optical encoders for precise cart position measurements
• Precise, stiff and heavy-duty machined components
• Fully compatible with MATLAB®/Simulink® and QUARC® control software and with LabVIEW™
• Sample model and control design documented and derived in Maple™ worksheet
• Open architecture design, allowing users to design their own controller
 AMD 1 floor structure Dimensions (L x W x H) 32 cm x 11 cm x 63 cm Total mass 2.85 kg Flexible structure height 50 cm Cart rack height 13 cm Flexible structure natural frequency 2.5 Hz Flexible structire linear stiffness 500 N/m Cart travel ± 9.5 cm Cart encoder resolution 4096 counts/rev Accelerometer sensitivity 1.0 g/V
 AMD 2 floors structure Dimensions (L x W x H) 32 cm x 11 cm x 113 cm Total mass 4.45 kg Flexible structure height (one floor) 50 cm 1st floor flexible structure linear stiffness (relative to the ground) 500 N/m 2nd floor flexible structure linear stiffness (relative to the 1st floor) 500 N/m Cart travel ± 9.5 cm Cart encoder resolution 4096 counts/rev Accelerometer sensitivity 1.0 g/V

Topics included in the Quanser-developed courseware:

• PV control
• Pole location
• State-space representation
• Transfer function representation
• State-feedback control
• Control parameter tuning
• Switching-mode control
##### The Active Mass Damper system can be used to teach also other topics not included in the Quanser-developed courseware.

To set up your Active Mass Damper workstation, you need additional components. Quanser engineers recommend:

 for MATLAB®/Simulink® users 1x Q2-USB data acquisition device¹ 1x VoltPAQ-X1 linear voltage amplifier QUARC real-time control software

¹ alternatively, you can use Q8-USBQPIDe, or any equivalent NI DAQ device supported by QUARC

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