Energy Harvesting Backpacks for Human Load Carriage: Modelling and Performance Evaluation

Abstract

In recent years, there has been an increasing demand for portable power sources as people are required to carry more equipment for occupational, military, or recreational purposes. The energy harvesting backpack that moves relative to the human body, could capture kinetic energy from human walking and convert vertical oscillation into the rotational motion of the generators to generate electricity. In our previous work, a light-weight tube-like energy harvester (TL harvester) and a traditional frequency-tuneable backpack-based energy harvester (FT harvester) were proposed. In this paper, we discuss the power generation performance of the two types of energy harvesters and the energy performance of human loaded walking, while carrying energy harvesting backpacks, based on two different spring-mass-damper models. Testing revealed that the electrical power in the experiments showed similar trends to the simulation results, but the calculated electrical power and the net metabolic power were higher than that of the experiments. Moreover, the total cost of harvesting (TCOH), defined as additional metabolic power in watt required to generate 1 W of electrical power, could be negative, which indicated that there is a chance to generate 6.11 W of electricity without increasing the metabolic cost while carrying energy harvesting backpacks.

Collecting the energy generated by manual workers to monitor their working status and improve their working conditions by using a flexible rack mechanism

“…As many researchers have delved into the field of human movement energy harvesting [9,10], an increasing number of energy harvesters that can be worn on the human body are being developed [11,12]. These energy harvesters convert the bioenergy collected from human movement into electricity [13], replacing or extending the life of traditional batteries that are used to power a wide range of wearable devices [14][15][16][17].…”

Harvesting Inertial Energy and Powering Wearable Devices: A Review

“…To attain optimal power generation from the generator, it is essential to carefully calibrate the constituent parts and their assemblies to ensure that the system's inherent frequency is in line with the excitation frequency. [ 32 ] It requires harmonising the spring's elastic constant k with the load‐bearing mass m , while considering $${\omega }_n = \sqrt {k/m} $$.…”

“…System damping, spring stiffness, and load mass have significant effects on the output performance of the energy-harvesting backpack. [32][33][34] At present, the key problem is how to reduce the complex mechanical structure and reduce the interference to the human body under the premise of ensuring the output power. Improving material properties, optimizing structural design, and improving the flexibility of energy-harvesting backpack are the keys to solve the above problems.…”

Experimental Energy Recovery from a Backpack Using Various Harvester Concepts

“…Mostafavi et al [19] presented the design and modelling of an energy-harvesting backpack that utilizes a mass-spring-damping oscillating system and a mechanical motion rectifier unit. The prototype designed for normal walking speed exhibited an average power of 4.37 W. Huang [20] discussed the power generation performance and efficiency of two types of harvesters installed in backpacks during human walking, suggesting the potential to generate electrical power of 6 W without increasing metabolic costs. Liu et al [21] conducted an analysis and comparison of three different backpacks, considering the dynamic interaction between the human body and the backpack.…”