Kenji Suto

Multi-mode and multi-axis vibration power generation effective for vehicles

This paper presents an effective method of power generation from the multi-mode and multi-axis vibration of a vehicle. First, road tests considering the mass and velocity variation are conducted and analyzed. Next, in order to select an optimal lead zirconate titanate (PZT) device for the power generation, no-load and load tests are performed. Based on the characteristic results of the vehicles vibration, a multi-mode and multi-axis power generator is proposed. Then, a prototype generator using the selected PZT device is developed. Finally, vibration experiments on both the vertical and horizontal axes are performed, and the effectiveness of the proposed multi-mode and multi-axis vibration power generator is verified through system identification results.

Comparison and evaluation of vibration-based piezoelectric power generators

Vibration energy regeneration with lead zirconate titanate piezoelectric (PZT) device has been reported by many researchers for many years. Various factors influence the energy regeneration efficiency of the PZT devices in converting the mechanical vibration energy to the electrical energy. This paper presents the analytical and experimental evaluation of energy regeneration efficiency of PZT devices through impedance matching method, energy regeneration efficiency of different shape of PZT devices, and effects of forced vibration input with concentrated load applied on the device to the PZT devices energy regeneration ability. The results show that the impedance matching method has increased the energy regeneration efficiency to between 4% and 88% while triangular shape of PZT device produce a stable efficiency in the energy regeneration. Besides that, it becomes clear that energy regeneration of triangular PZT device as well as its efficiency is optimum with auxiliary mass of 2.6g.

Multi-mode vibration-based power generation for automobiles

This paper presents a novel vibration power generation device for vehicles where effective power generation can be obtained by multi-mode vibration of the vehicles. First, road tests of the vehicle are performed, and then, the obtained data is analyzed. Next, a vibration power generation device specially designed for the vehicle is proposed. This new device is composed of multiple masses and spring plates equipped with a lead zirconate titanate (PZT), and is effective in multi-mode vibration. The validity of the developed device is confirmed by the simulation and experimental results.

The Effect of the Parameters of a Vibration-Based Impact Mode Piezoelectric Power Generator

This study reports the effects of the parameters of a vibration-based impact mode piezoelectric power generator. First, an evaluation of the effects of the impact parameters, the mass, and the impact velocity is presented. It is found that the output voltage of the piezoelectric device in impact mode is directly proportional to the velocity, whereas the output power is equal to a quadratic function of the same variable. For the same impact momentum, the effect of the velocity in generating a higher peak output is dominant compared with the mass. Second, the vibration-based impact mode piezoelectric power generator is discussed. The experimental results show that a wider operating frequency bandwidth of the output power can be achieved with the preloading configuration. However, regarding magnitude, due to the high velocity of impact, the configuration with a gap between the tip and the piezoelectric device produces a higher output.

Reproduction of Vehicle Vibration by Acceleration-Based Multi-Axis Control

This paper presents the development of the 3-axis vibrating machine precisely reproducing vehicles acceleration characterized with multi-mode vibration. For the reproduction in vertical axis, at first, the system identification experiment of the vibrator is carried out. Using the identified model, the feedforward control based on the pole-zero cancellation method is applied to realize the ideal transfer gain of one from the acceleration reference to its output. Next, for reproducing the acceleration in horizontal plane, the continuous-path tracking (CPT) control system is constructed using the precision XY stage. In the CPT control system, the disturbance observer is introduced focusing on the accurate reproduction within limited frequency. Finally, the experimental verification of the proposed 3-axis acceleration vibration reproduction system is shown using the developed DSP-controlled 3-axis vibrating machine.

A flapping-based piezoelectric power generator for bicycle applications

We demonstrate a novel structure of a flapping-based piezoelectric power generator for bicycle pedals. The flapping structure and the circuit configuration have been proposed, and the effectiveness of the proposed structure is experimentally evaluated by the bicycle trainer. In the proposed structure, the number of lights can be freely selected by changing the number of flapping poles, and the light colors of the front and rear LEDs can be automatically switched by using the pedaling force. In addition, the flapping-based piezoelectric power generator can be easily applied to the commonly-used bicycle pedals.

Evaluation on mechanical impact parameters in piezoelectric power generation

This paper presents a study on effect of two mechanical impact parameters on impact mode piezoelectric power generation. The parameters are velocity and mass. Free fall experiment is used as the evaluation method. It turns out that peak of instantaneous output voltage is proportional to the impact velocity and for output power it is in a straight line relationship with the same parameter. For the same impact velocity, advantage in the usage of heavy object becomes clearer as its momentum and impact force are higher. However, adjustment in the velocity of impact is found to be more effective for higher instantaneous output power than the mass. This is proven by the output power which has been generated by 4g steel ball with momentum of 4.34gm/s is nearly 300% higher than that of 8g steel ball for the same momentum. Further analysis with forced vibration-based impact mode piezoelectric power generation experiment shows that the same conclusion can be made.

A Multi-Mode Vibration-Based Power Generator for Vehicles

This paper presents a novel vibration power generation device for vehicles where effective power generation can be obtained by multi-mode vibration of the vehicles. First, road tests of the vehicle are performed, and then the obtained data is analyzed. Next, a vibration power generation device specially designed for the vehicle is proposed. This new device is composed of the multiple masses and spring plates equipped with lead zirconate titanate (PZT), and is effective in multi-mode vibration. The validity of the developed device is confirmed by the simulation and experimental results.

Multi-Axis Vibration Power Generation Device for Automobiles

In achieving the practical use of vibration power generation, the challenges are that the energy to be generated is small and the vibration frequency range for efficient power generation is limited. So, it is needed to improve the output level and establish a vibration transmission structure capable of covering a wider vibration frequency range. In this report, we propose a multi-axis vibration power generation device that is mounted on the vehicle and capable of generating electric power from vibrations in the running vehicle and evaluate its principle model based on the stress analysis. For the model, we employed the structure in which the elastic body (a flat spring with piezoelectric elements on it) is deflected by mass vibration and the elements are bent and strained. We made two types of the principle models using the same elastic body; one is H-type having a mass on both sides of the elastic body, and the other is T-type having a mass on one side only, and conducted tests for the system identification of them.

Development of a Wiper System with Piezoelectric Element for CCD Camera

We succeeded in creating of a very small wiper system for a CCD camera. The source of driving force of it is a vibration phenomenon of a piezoelectric element. In this paper, we will describe the structure and motion of our newly proposed wiper system and the fundamental motion of a piezoelectric element in it. And in order to clarify the driving principle, we carried out a theoretical analysis using the Principle of Hamilton. As a result, a driving mechanism was found, that is, when the blade displaces at a high angular velocity into one direction, the shaft rotates in the opposite direction. We were able to confirm the driving mechanism also by experiments.