Ultima Computing : Jurnal Sistem Komputer, Vol. 13, No. 2 | December 2021 50 ISSN 2355-3286 Modeling and Controlling the Actuator Joint Angle Position on the Robot Arm Base Using Discrete PID Algorithm Machdiar Rohman 1 , Dede Irawan Saputra 2 Universitas Jenderal Achmad Yani, Program Studi Teknik Elektro Cimahi, Indonesia 1 machdiarrohman@gmail.com, 2 dedeirawan.saputra@lecture.unjani.ac.id Accepted 09 June 2021 Approved 22 September 2021 Abstract— DC motor is a motor that is easy to apply. Its application in robotic DC motor control often occurs errors due to the existing load, so that the DC motor becomes inaccurate. The control used is PID (proportional integral differential). This PID control system works by processing calculations based on the control variables Kp, Ki, and Kd to achieve the conditions according to the expected setpoint. To make a DC motor position control device can be controlled with a PID controller. In practice, the variable to be controlled in this research is position control in the form of degrees. With the Arduino Mega controller, the motor driver as a DC motor rotation controller, the DC motor is given feedback in the form of an encoder sensor, the software used is the Arduino IDE. The results showed that PID control can correct errors and transient responses with a time constant value of 1.50 seconds, a rise time of 1.60 seconds, a settling time of 2.30 seconds and a delay time of 1.20 seconds and a peak time of 1.6 seconds and an error value of 0.33% through tuning parameter Kp = 16 Ki = 0.001 Kd = 16. Index Terms— Motor DC, Discrete PID, System response I. INTRODUCTION DC motor is a type of drive that is often used in all fields, one of which is the field of robotics and control [1]. DC motors in the field of robotics can be controlled to regulate speed [2], position or a combination of them [3]. DC motor has a fast response, but still has a steady state error [4]. To reduce steady state error value of DC motor as position control, a controller is needed. The PID controller is the most widely used because it is simple and easy to learn and tuning its parameters. More than 95% of processes in the industry use these controllers. This controller is a combination of proportional (P), integral (I), and derivative (D) controllers [5], [6]. In most speed control systems, what is desired is to keep the rotational speed constant for all load conditions, not set the rotational speed to vary over time as the reference input changes. Not so with the positioning system. In these systems, system accuracy is usually measured not only by steady-state error for step inputs, but also by steady-state error for time- varying inputs. This is usually termed as following error. The addition of a PID controller can actually improve performance of positioning system in terms of magnitude of this following error [7]. As for some control positions for application of DC motors in the field of robotics, namely controlling position of motor on the goods moving robot with input in form of images that are read by camera [8]. Then, control the PID Training Kit ELABO TS 3400 Using a Position Sensor which is implemented on a DC motor whose control uses a potentiometer [9] Next, the use of a DC motor on an arm flip folding machine that uses PID control [10]. In this study, the application of a DC motor to the basic motion of the robot arm will be carried out to determine the position of the robotic base arm using the discrete PID method by providing input via a serial monitor. The design of base arm robot is carried out by using actuator base arm robot in form of a brushed DC motor to achieve the angular position of encoder sensor [11] with motor control in form of the PID method [12]. There are several approaches that can be implemented, one of which is discrete PID [13]. The design of the PID controller in discrete domain is expected to approach the application of using a microcontroller and is expected to be able to increase transition response and reduce the value of base movement error with a predetermined constant on the PID controller. The determination of initial design carried out by transfer function modeling process using identification system of open loop and close loop approaches [14] with System Identification Matlab tools [15]. II. DESIGN SYSTEM A. Movement Mechanism Design At this point components that used in the robotic arm are computer controller which functions is to determine the input angle which inputted through the