The concept of pulse width modulation is discussed, particularly from the viewpoint of its use in control systems. The effects and implementation of pulse width modulation are considered.
The concept of pulse width modulation is discussed, particularly from the viewpoint of its use in control systems. The effects and implementation of pulse width modulation are considered.
pulse width modulation (PWM) control is investigated for the Mecanum-wheeled mobile robot (MWMR) driven by servo motors with random disturbance. As a preliminary, PWM strategy of random nonlinear systems is obtained b...
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pulse width modulation (PWM) control is investigated for the Mecanum-wheeled mobile robot (MWMR) driven by servo motors with random disturbance. As a preliminary, PWM strategy of random nonlinear systems is obtained by the aid of the functional analysis tool. A smooth voltage controller is presented by the backstepping technique for MWMR. Based on the boundedness of input voltage caused by direct-current motors, the optimal bounded controller is obtained by the quadratic programming method. Therefore, the optimal duty ratio is generated by the positive part and the negative part of the optimal control, the digital controller is synthesized in turns. Finally, a simulation example is given to demonstrate the efficiency of the proposed PWM scheme.
Solid-state lasers are usually used as excitation light sources for measuring the upconversion luminescence spectra. But the output power of this kind of laser usually jitters at unsaturated output circumstances, lead...
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Solid-state lasers are usually used as excitation light sources for measuring the upconversion luminescence spectra. But the output power of this kind of laser usually jitters at unsaturated output circumstances, leading to unstable luminescence intensity and affecting the accuracy of excitation threshold measurement. Herein, pulse width modulation was used for adjusting the power of a 532 nm solid-state laser for measuring the upconversion threshold. The average output power of lasers can be adjusted by changing the pulsewidth at a constant pulse frequency. The stability is significantly higher than that of the output power using current modulation. The excitation threshold estimated by this method is similar to that of the continuous light excitation. pulse width modulation is expected to be applied to other lasers in power modulation and will play an important role in fluorescence detection and imaging.
This paper presents a fully integrated digital pulse-width-modulation three-level DC-DC buck converter. An internal switching frequency of 100 MHz is selected to minimize the value of passive components, and the packa...
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This paper presents a fully integrated digital pulse-width-modulation three-level DC-DC buck converter. An internal switching frequency of 100 MHz is selected to minimize the value of passive components, and the package bond-wire based inductor is selected. In the integrated voltage regulator, a three-level structure is used to reduce the output voltage ripple, and Digital pulse width modulation (DPWM) is employed to achieve efficient current and voltage control. This digitally configured control scheme is robust against external environmental factors, such as process, voltage, and temperature variations, and also achieves a fast load transient time. The proposed circuit is fabricated using a 130-nm BCDMOS process, and it can regulate the 5-V input voltage to the output voltage range of 3.3-3.7 V. The three-level buck converter with an active area of 1.035 mm(2) shows a power conversion efficiency of 72.4% under the load current of 200 mA.
This paper proposes a novel spike generator for processing in memory (PIM) technology. Most of the electronics today utilize a von Neumann architecture. The von Neumann architecture suffers from the separation of memo...
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Recently, higher display resolution of flagship smartphones has contributed to better quality 3D image rendering and mobile gaming applications. However, high-resolution displays require source-driver ICs (SD-IC) with...
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Compared with conventional space vector pulse width modulation (SVPWM), discontinuous pulse width modulation (DPWM) technique is esteemed for lower switching losses and more flexible sampling options. Moreover, the th...
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This paper proposes a control method with control frequency asynchronous to pulse width modulation (PWM) frequency for Vienna rectifier to enhance the stability when connected to the grid. By analyzing the bode diagra...
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Microwave wireless power transfer (MWPT) can realize long-range power transmission compared with other wireless power transfer techniques. The traditional MWPT system is based on a continuous power supply structure. W...
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Although diversified control schemes have been reported for ionic-polymer metal composites (IPMC) actuators, maneuvering the IPMC actuator in a static position with a large displacement for a long time is still challe...
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Although diversified control schemes have been reported for ionic-polymer metal composites (IPMC) actuators, maneuvering the IPMC actuator in a static position with a large displacement for a long time is still challenging because of its highly intrinsic non-linear and hysteresis characteristics. Instead of using a complex model, a simple and systematic control scheme based on the pulse width modulation (PWM) driving signal and feedforward compensation was first reported to solve this issue. We present the fabrication of the tested IPMC actuator and ensure its continuous alternative motion of amplitude 8 mm for more than 20 min. The fixed position control methodology is sequentially applied: examining the unipolar PWM signal test to find the optimal driving frequency, characterizing the delayed time and displacement by bipolar PWM signal, and performing closed-loop feedforward control of the IPMC actuator with optimal frequency bipolar PWM signal and delayed displacement compensation. Furthermore, a novel scheme was created to predict the occurrence of the wellknown perplexing back-relaxation behavior of the IPMC actuator by simply processing the control signal. With this control methodology, the underwater fixed position control in the range of +/- 4 mm, control time for 8 min, and above 50 % position error improvement compared to that without feedforward compensation have been demonstrated. The control results also show that the perturbation amplitude of the IPMC actuator around the setting position can be tuned. This control methodology paves the way for the versatile and practical operation of IPMC actuators.
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