Designing a controller that balances two links adds an extra challenge when compared to the single inverted pendulum system. The additional challenge of a second pendulum can be used to demonstrate advanced controls concepts, or as a basis for research.
Linear Double Inverted Pendulum
The double inverted pendulum represents a complex challenge with real-world applications that include stabilizing the takeoff of a multi-stage rocket and modeling the human posture system.
The force between electromagnet and ball is highly nonlinear. Further, the electromagnet itself has its own dynamics that must be compensated for. The challenging dynamics of the system make it perfect for teaching modeling, linearization, current control, position control, and using multiple loops (i.e. cascade control). It could also be used to test and implement more advanced control strategies, such as multi-variable, gain scheduling, and nonlinear control.
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.
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.
Designed in association with Prof. Karl Åström and Prof. Karl Henrik Johansson, the Coupled Tanks system consists of a single pump with two tanks. Each tank is instrumented with a pressure sensor to measure the water level. The pump drives the water from the bottom basin up to the top of the system. Depending on how the outflow valves are configured, the water then flows to the top tank, bottom tank, or both. The rate of flow can also be changed using outflow orifices with different diameters. The ability to direct water flow, together with variable outflow orifices allows for several interesting Single Input Single Output (SISO) configurations. Further, two or more Coupled Tanks can be combined together for Multiple Input Multiple Output (MIMO) experiments.
QLabs Controls is a collection of virtual laboratory activities that supplement traditional or online control systems courses. The virtual hardware labs are based on Quanser QUBE-Servo 2 and Quanser AERO systems which allows you to combine physical and virtual plants to enrich lectures and in-lab activities and increases engagement and students’ learning outcomes in class-based or online courses.
Same as the physical Coupled Tanks, the virtual system features a single pump and two tanks. Each tank is instrumented with a pressure sensor to measure the liquid level. The different outflow valves configurations allow to direct the flow of the liquid, while the flow rate can be changed by using outflow orifices of different diameters.
The 3 DOF Gyroscope consists of a disk mounted inside an inner gimbal which in turn is mounted inside an outer gimbal. The entire structure is supported by a rectangular frame that is free to rotate about its vertical axis of using a slip ring design. The gimbals are also equipped with slip rings, allowing them to rotate freely and giving the disk three degrees of freedom. The plant is equipped with four DC motors and four encoders, with the ability to fix individual axis. Axes positions are measured using high-resolution optical encoders. Although the gimbals and outer frame are free to rotate, the plant provides the ability to fix any desired axis (outer frame, red and blue gimbals).