## 1 Introduction
In consideration of the costs and control complexity/accuracy, stepping motors with open-loop control are applied to many products. Accordingly, stepping motors are also used for positioning and discharging control in this study. There have been many research works on stepping motors carried out in the past. Reference [9] uses a back-electromotive force (back-EMF)-based load angle estimation (a senseless load angle estimator) for step loss detection and stall detection of a stepping motor. Reference [10] analyzes the working mode of stepping motors in half step and full step in dynamic conditions at different frequencies. Reference [11] proposes an adaptive control of a stepping motor drive using a hybrid neuro-fuzzy approach in which the ANFIS [12] is used to build a Sugeno fuzzy model for controlling the stepping motor drive. Reference [13] presents an application of the fuzzy logic principle to control the speed of a stepping motor drive in a closed-loop control and uses a low-cost microcontroller to verify design performance. Reference [14] shows a LabView-based soft control method for the starting acceleration and stopping deceleration stages of stepping motors. Reference [15] presents a controller driver for a 2-phase stepping motor with full step sequence, using a voltage to frequency converter. The acceleration/deceleration control curves of trapezoidal and new S model of a stepper motor under the open-loop control based on Microcontroller Unit (MCU) were studied in Reference [16], and the relationship curve between the control pulse and time was discretized to determine the stepping motor control scheme. The results showed that the acceleration/deceleration control of the new S model exhibited little noise, high positioning accuracy, and good flexibility. Reference [17] studied the open-loop stepping drive of PMSM (permanent magnet synchronous motor) using an open-loop compensation method of PWM dead-time to improve the control precision of the winding current and the precision of the step interval under stepping drive mode. Reference [18] discusses the implementation of an open-loop stepping motor drive controller using CPLD; the improvement in CPLD computing speed improved the performance of the controller. Reference [19] proposed a control scheme for reducing the resonance of hybrid stepping motors. The motor currents are controlled in a synchronously rotating frame with excitation frequency. The d-axis current provides the torque for the external load, and the q-axis current provides the transient torque for damping the motor. The angle of the motor back-EMF is used by an observer to estimate the motor speed. The simulation and experimental results showed that this proposed method was able to effectively damp the resonance of micro-stepping controlled motors. Reference [20] showed that the spontaneous reverse speed of a permanent magnet stepping motor when controlled in full step, open-loop mode was equal to three times the forward speed. The reverse running will arise when the undershoot of the single-step response exceeds 50% (or a damping factor of less than 0.11). The growth of the undershoot in response to repeated steps will cause resonance problems, including stalling and speed reversal. Most past research works on weighing have focused on error correction and dynamic response compensation. Reference [21] proposed a practical compensating method for the creep error in load cells through the use of digital processing. A weighted composite function as a compensation function for use in flexibly expressing a creep error curve and a compensation model for calculating the amount of compensation corresponding to the weight loading history were presented. However, the weight being measured in this research was in kg, while the weight measured in our study is in g. Reference [22] applied a double load cells self-balance method for measuring the static load of bridges. Reference [23] proposed a novel model-based signal filtering technique to improve the dynamic measurement of load cells.