Abstract
This article describes the control of a rotary inverted pendulum utilizing on–off-type cold gas thrusters as the actuators, which have high similarities with thruster actuated spacecrafts with slosh dynamics. The study is completed in three phases. Firstly, a Pulse Width Modulator (PWM) design method is utilized to obtain quasi-linear thrust output from the on–off-type thrusters. Then, a single axis angle controller is designed and tested on the setup along with the PWM scheme. Finally, a pendulum is connected to the other end of the platform and a rotary inverted pendulum (Furuta Pendulum) is constructed. In this way, an inherently unstable, under-actuated, on–off driven system is obtained. For the swing-up motion of the pendulum, an energy-based method is employed. Balancing of the pendulum is achieved by an observer-based state feedback controller under small angle assumption and quasi-linear outputs from the PWM driven thrusters. All of these control methodologies are realized on a real-time target machine. The pendulum is stabilized in seven seconds after five swings, which is comparable to the systems with electric motors.
Highlights
Cold gas thrusters have been used in the space industry since the 1960s
There are differences in terms of dynamical characteristics between the cold gas types and other types of thruster systems, control strategies applied to the cold gas thrusters can be applied to any kind of thruster system with some modifications
Pulse Width Modulator (PWM) actuated cold gas thrusters were used for the control of a rotary inverted pendulum
Summary
Cold gas thrusters have been used in the space industry since the 1960s. They are preferred for all ranges of orbits and inter-planetary missions [1]. The inverted pendulum system is a classical control problem application that has been used for decades The system, whether it is rotary or linear, has inherently unstable, under-actuated and nonlinear dynamical characteristics. Reaction masses and control moment gyroscopes are commonly used for spacecraft attitude control applications In this work, another type of reaction control system, the cold gas thruster, is used as an actuator for the rotary inverted pendulum system. The main difference and challenge when compared with other types of actuators is that the cold gas thruster system used in this work is an on–off type of actuator. Inverted pendulums have not been actuated by on–off-type thrusters before in the literature This is the first study employing such actuators with the conventional control approach for rotary inverted pendulums.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
