Backstepping Control of an Industrial Delta Parallel Robot Model Selim Sivrioglu Department of Mechanical Engineering Piri Reis University Istanbul, Turkiye ssivrioglu@pirireis.edu.tr G. Ceyda Hacıoglu Graduate Student Department of Mechanical Engineering Piri Reis University Istanbul, Turkiye A. Suat Yıldız Department of Mechanical Engineering, Sivas University of Science and Technology, Sivas, Türkiye Abstract— In this research, a backstepping control design has been realized to improve the trajectory tracking performance of a delta robot system, which stands out with their lightness, speed and precision. As a result of the forward-inverse kinematic analysis of the delta robot system, the working area was determined, and different trajectory scenarios were created to remain within this area. The control performance under these designed trajectory conditions was tested in simulation studies. Keywords—delta robot model, trajectory performance, backstepping control I. INTRODUCTION Robots are generally classified as serial and parallel. Today, serial robots are mainly used in many industrial applications. Large mechanisms and heavier joints are used in serial robots where the axes are built on top of each other. Unlike serial robots, the joints are not placed on top of each other in parallel robots, but are all positioned on the same body. Thus, no arm has to lift the next one, and does not encounter the negativities caused by an unnecessary load. All axes provide the required workload without lifting the body of the robot. With the lightening of the robot joints, the inertias are also reduced, allowing the motors to work more dynamically and efficiently. In parallel robots, more precise positioning is possible because errors are not added to each other. They also move faster and consume less energy than serial robots. The most important reason for this is that the axes that transmit the movement are lighter. However, there are situations that limit parallel robots use and require the use of serial robots instead of parallel robots in some applications. The use of parallel robots is limited in practice because they narrow the closed- loop working space between their limited moving axes. Delta robots and other parallel robots have become popular in surgical applications because of their potentially high-precision operating principles. In recent years, the use of parallel robot structures in three-dimensional printers has become very common. The active use of 3D printers in the production area has generally led to developments in the research of parallel robots. Recently, there are many academic studies on the optimization of delta robots and multi-axis control systems[1-5]. In addition to conventional control strategies, various robust and nonlinear control approaches have also been developed for Delta parallel robots to improve tracking performance and handle uncertainties[6,7]. In this research paper, an industrial delta robot is studied to improve trajectory performance. A Lyapunov based backstepping control is designed using the obtained dynamic model of the delta robot. The controller performance is tested for a desired pick and place trajectory on a simulation model. II. STRUCTURE OF DELTA ROBOT A delta parallel robot is a three-degree-of-freedom rod mechanism connected to each other at an angle of 120 degrees between the fixed platform and the mobile platform to which the end processor is attached. An experimental use industrial delta robot structure is shown in Fig.1. It has components of servo motor with gear box, fixed platform, moving platform, long arm, short arm and supporting legs as shown in Fig.1. Parameters of delta robot is given in Table I. Fig.1 Layout and elements of delta robot [8] TABLE I. DELTA ROBOT PARAMETERS Meaning Symbol Value Radius of the fixed platform  105 mm Edge of triangle fixed platform  117 mm Length of short arm   150 mm Length of long arm   400 mm Radius of moving platform ℎ 34 mm Mass of the input link   0.168 kg Mass of one of the two connecting arms   0.300 kg Mass of the moving platform   0.215 kg III. DELTA ROBOT MODELING A. Forward Kinematic Analysis The aim of a kinematic analysis of delta robot mechanism is to determine the movement relationship between the joints. Cartesian coordinate values can be obtained from the angle values of the joint points with forward kinematic analysis. In delta robots, it is difficult to calculate kinematics since it is a closed loop manipulator. To simplify the model and reduce the number of parameters, the following assumptions are made. The moving plate always remains parallel to the base plate and its orientation about the axis perpendicular to the base plate is always zero. Thus, the parallelogram type links (long arm) can be replaced by simple rods without changing the robot’s kinematic behavior. The rotary joints 979-8-3315-1088-6/25/$31.00 ©2025 IEEE 2025 7th International Congress on Human-Computer Interaction, Optimization and Robotic Applications (ICHORA) | 979-8-3315-1088-6/25/$31.00 ©2025 IEEE | DOI: 10.1109/ICHORA65333.2025.11017056 Authorized licensed use limited to: ULAKBIM UASL - Piri Reis Univeristesi. Downloaded on June 10,2025 at 17:21:37 UTC from IEEE Xplore. Restrictions apply.