The Ball and Beam module is ideal to introduce various control concepts related to unstable closed-loop systems. You can use it to demonstrate real-world control challenges such as aircraft roll control. The Ball and Beam module attaches to the Rotary Servo Base Unit.
Ball and Beam
The Ball and Beam module consists of a steel rod in parallel with a nickel-chromium, wire-wound resistor forming the track on which the metal ball is free to roll. The track is effectively a potentiometer, outputting a voltage that’s proportional to the position of the ball.
When coupled to the Rotary Servo Base Unit, the tilt angle of the beam can be controlled by changing the servo gear angle. The Ball and Beam module can be operated in stand-alone mode, and the ball position can be controlled via the user interface.
| Brand | Quanser |
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The experiment is reconfigurable for various aerospace systems, from 1 DOF and 2 DOF helicopter to half-quadrotor. Integrating Quanser-developed QFLEX 2 computing interface technology, the Quanser AERO also offers flexibility in lab configurations, using a PC, or microcontrollers, such as NI myRIO, Arduino and Raspberry Pi. With the comprehensive course materials included, you can build a state-of-the-art teaching lab for your mechatronics or control courses, engage students in various design and capstone projects, and validate your research concepts on a high-quality, robust, and precise platform.
2 DOF Ball Balancer
The 2 DOF Ball Balancer module consists of a plate on which a ball can be placed and is free to move. Two Rotary Servo Base Units are connected to the sides of the plate using 2 DOF gimbals. The plate can swivel about in any direction. By controlling the position of the servo load gears, the tilt angle of the plate can be adjusted to balance the ball to a desired planar position.
The digital camera mounted overhead captures two-dimensional images of the plate and track coordinates of the ball in real time. Images are transferred quickly to the PC via a FireWire connection. Students can make the ball track various trajectories (a circle, for example), or even stabilize the ball when it is thrown onto the plate using the controller provided with the experiment.
2 DOF Inverted Pendulum
The 2 DOF Inverted Pendulum module consists of an instrumented 2 DOF joint to which a 12-inch rod is mounted. The rod is free to swing about two orthogonal axes. The module is attached to two Rotary Servo Base Units. Their servomotors’ output shafts are coupled through a four-bar linkage, i.e., 2 DOF Robot module, resulting in a planar manipulator robot. The 2 DOF Joint is attached to the end effector of the robot arms.
The goal of the 2 DOF Inverted Pendulum experiment is to command the position of the 2 DOF Robot end effector to balance the pendulum. By measuring the deviations of the vertical pendulum, a controller can be used to rotate the servos, so that the position of the end effector balances the pendulum.
Rotary Servo Base Unit
The Rotary Servo Base Unit is a geared servo-mechanism system. The plant consists of a DC motor in a solid aluminum frame. This DC motor drives the smaller pinion gear through an internal gear box. The pinion gear is fixed to a larger middle gear that rotates on the load shaft. The position of the load shaft can be measured using a high resolution optical encoder or a potentiometer. The encoder is also used to estimate the speed of the motor.
Rotary Flexible Joint
The Rotary Flexible Joint module consists of a free arm attached to two identical springs. The springs are mounted to an aluminum chassis which is fastened to the Rotary Servo Base Unit load gear. The module attaches to a DC motor on the Servo Base Unit that rotates a beam mounted on a flexible joint. The Rotary Flexible Joint module is supplied with three distinct pairs of springs, each with varying stiffness. It comes with three base and three arm anchors for the springs, and allows to obtain a wide variety of joint stiffness. The module is also supplied with a variable arm load that can be mounted at three distinct anchor positions to change the length of the load.
Rotary Double Inverted Pendulum
The Double Inverted Pendulum module is composed of a rotary arm that attaches to the Rotary Servo Base Unit, a short 7-inch bottom blue rod, an encoder hinge, and the top 12-inch blue rod. The balance control computes a voltage based on the angle measurements from the encoders. This control voltage signal is amplified and applied to the Servo motor. The rotary arm moves accordingly to balance the two links and the process repeats itself.
Multi-DOF Torsion
The Torsion Module is a rotary torsional system that consists of an instrumented bearing block, which is mounted in a cubic aluminum frame. A shaft is free to spin inside the bearing block and its angle is measured using an encoder. The shaft can be fitted with either a torsional load or a flexible coupling.
The assembly made of one Rotary Torsion module coupled to a Rotary Servo Base Unit constitutes one Degree of Freedom (1 DOF) torsional system. The Rotary Servo Base Unit lies on its side so that its DC motor and output shaft are horizontal and able to rotate a flexible coupling attached to a rotational load. The torsional load consists of two inertial disc masses, which can be located at different anchor points along their support bar. Up to seven torsion modules can be coupled in cascade to allow for multi-dimensional control problems.
