Six Degrees of Freedom Robotic Testbed for Control Systems Laboratory Muhammad Awais Arshad, Muhammad Majid Gulzar, Jawad Khalid Qureshi, Aamir Hayat Faculty of Engineering University of Central Punjab Lahore, Pakistan awais_arshad@ucp.edu.pk Mohammad Shamir, Fawad Ahmed, Sadia Rasheed National Transmission and Despatch Company Water and Power Development Authority Lahore, Pakistan Abstract—A 6-DoF robotic testbed has been proposed, designed and developed for university students to learn the concepts of control systems theory in robotics. Testbed is comprised of two parts namely; 6-DoF platform and ball-plate balancing payload. Robotic maneuvers in platform are generated through rotary Stewart- Gough mechanism using inverse kinematic algorithm. Ball-plate balancing payload is fixed on top of platform. This paper presents a comparison among generic testbeds, available at standard control system laboratories. Design of robotic platform along with payload has been detailed and tested with software simulations in MATLAB Simulink. This work explains complete electrical, mechanical and software design along with development, testing and results. Keywords—ball-plate system; control system; degrees of freedom; rotary; robotic testbed; Stewart I. INTRODUCTION Dynamical systems (living organisms, electrical and electronic systems, mechanical systems, electromechanical systems, industrial systems, market behaviors, ecology, and so forth) can be considered, analyzed and controlled using information and system theories. As an illustrative example, the driver controls a car by managing speed, acceleration and steering wheel position using incoming information, such as traffic congestion, weather conditions, road conditions, red light monitoring, road signs etc. Concepts related to the control of dynamical systems are studied under the discipline of control system theory. Control system engineering is of significant interest in broad spectrum of science and technology and is applied to major advanced systems including but not limited to aircrafts, satellites, launch vehicles, rockets, missiles, submarines, torpedo, and cars [1]. Because of its diverse applications and industrial significance, control system engineering is a core subject for electrical, mechanical, mechatronics, chemical and aerospace engineering students. Engineering institutes develop control system laboratories for students to learn and practice control system theory. Control system laboratories are equipped with educational testbeds with applications specific to relevant industries. A good testbed for control system laboratory include some sensors/transducers, actuators, plant, input reference, input filter and comparator. Most common testbeds include inverted pendulum, DC/AC modular servo systems, magnetic levitator, twin rotor system, pneumatic servo systems, hydraulic servo systems etc. Twin-rotor-system control is somewhat similar to the control of a helicopter where two different rotors are provided to controls the horizontal level and direction of a beam. Inverted pendulum is considered a standard control laboratory equipment to be used by students to stabilize a naturally unstable system through different control schemes. Magnetic levitation testbed is used to magnetically levitate a ball at a particular height in free air using electro-magnetic force by controlling the current passing through electro-magnet. 2-DoF Ball-and-plate balancing system is also used as a control system laboratory testbed where position of a ball is controlled onto a plate under the action of gravitational force and rotational forces on plate in two degrees of freedom. Instantaneous position of a ball is detected either with a touch sensitive plate or with the help of digital camera on top of plate. Aforementioned educational testbeds are good for basic understanding of fundamental concepts in linear control system theory but very simple to work with. Ordinary educational testbed cannot challenge the cognitive or psychomotor skills of university students. Advanced industrial robotic systems, on the other hand, are quite complex and require good expertise in dynamic/kinematic modelling, algorithm design, sensor data processing, actuator commanding and cascaded control system design. Considering above mentioned industrial requirements, this paper proposes a testbed for control system laboratories which is a compromise between ordinary simplistic educational testbeds and complex advanced industrial systems. Proposed testbed is comprised of two parts namely; 6-DoF platform and ball-plate balancing payload. Ball-plate balancing payload is fixed tightly on the top of 6-DoF platform as shown in Fig. 1. Theme of this testbed is to move testbed in such a way that it can control the position of ball placed freely on plate. Instantaneous position of ball is detected with the help of a digital camera and associated digital image processing scheme. Ball-plate payload, fixed to platform, can execute six different maneuvers (roll, pitch, yaw, serge, sway and heave) with ranges of ±10 degrees in rotational domain (roll, pitch and yaw) and ±10cm in translational domain (serge, sway and heave). 978-1-5386-2234-6/17/$31.00 ©2017 IEEE .