Arch Appl Mech https://doi.org/10.1007/s00419-019-01571-8 ORIGINAL Armen Nunuparov · Felix Becker · Nikolay Bolotnik · Igor Zeidis · Klaus Zimmermann Dynamics and motion control of a capsule robot with an opposing spring Received: 6 September 2018 / Accepted: 29 May 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Non-classical locomotion systems have the perspective for a wide application in the vast fields of bio-medical and maintenance technology. Capsule bots are small, simple, and reliable realizations with a great potential for practical application. In this paper, the motion of a capsule-type mobile robot along a straight line on a rough horizontal plane is studied applying analytical and experimental methods. The robot consists of a housing and an internal body attached to the housing by a spring. The motion of the system is generated by a force that acts between the housing and the internal body and changes periodically in a pulse-width mode. The average velocity of the motion of the robot is studied as a function of the excitation parameters. The results from the model-based and experimental investigations agree with each other. It can be concluded that the presented robot design can be a basis for the creation of mobile robotic systems with locomotion properties that can be controlled by the parameters of a periodic actuation force. Keywords Mobile robot · Motion control · Capsubot · Locomotion · Self-propulsion · Vibration-driven system 1 Introduction A capsule robot (capsubot) is a locomotion system that can move in a resistive environment without external propelling devices (legs, wheels, caterpillars, fins, water screws, etc.) due to the motion of internal bodies and interaction of the housing with the environment. A capsule robot consists of a rigid housing (capsule) and internal bodies that can be driven relative to the housing by actuators. The actuators provide interaction of the internal bodies with the robot’s housing. The forces applied by the actuators to an internal body cause the reaction force applied to the housing, due to which the velocity of the housing relative to the environment A. Nunuparov Moscow Institute of Physics and Technology, Dolgoprudny, Russia E-mail: anunuparov@me.com A. Nunuparov · N. Bolotnik Laboratory of Robotics and Mechatronics, Institute for Problems in Mechanics of the Russian Academy of Sciences, Moscow, Russia E-mail: bolotnik2004@mail.ru F. Becker · I. Zeidis (B ) · K. Zimmermann Technical Mechanics Group, Technische Universität Ilmenau, Ilmenau, Germany E-mail: igor.zeidis@tu-ilmenau.de F. Becker E-mail: felix.becker@tu-ilmenau.de