IDENTIFICATION OF IMPULSE RESPONSE OF DYNAMIC MODEL OF PROTOTYPE SUSPENDED LOAD BACKPACK WITH MOTION CAPTURE SYSTEM FOR EVALUATION BACKPACK PERFORMANCE BASED ON DYNAMICS OF FREQUENCY RESPONSE TO LOAD VARIATIONS

• Main Author: Fikri El Faiz, Dzar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/52586
• Institution: Institut Teknologi Bandung

Many people wear backpack from different jobs or groups in their daily life. The type of backpack can be determined from which user and what purpose, and for every type of backpack there is maximum load which cannot be exceeded. The reason is the excessive backpack load can cause injury, coupled with the impact force of the backpack which is the implication of dynamic user activity. The magnitude of the impact force could exceed the weight of backpack itself, thereby can increase the likelihood of injury to the user. The impact force can be minimized if conventional backpacks are added with suspension system, thereby can make the load float relative to the part of backpack which is fixed on the back of the body. Based on the concept of the basic form and function from suspended load backpack, Kelompok Keahlian Manusia dan Produk Industri – Desain Produk ITB is currently developing prototype of suspended load backpack which functionally can carry loads. To acquire the benefit from the use of suspended load backpack in many load variations carrying, the dynamic parameter identification is required for the prototype. Ideally, a shaker machine can provide sinusoidal deviation input that can be adjusted over a certain frequency range to simulate walking and running conditions. But unfortunately the facility is still not available in ITB. This thesis conducted alternative method in the form of impulse response identification from the suspended load backpack prototype, in which the change of deviation of floating load on backpack was being monitored by high speed motion capture. Then parameter identification is conducted from the transient response data of floating load deviation to each mass experiment ranged from 0-5 kg with 0.25 kg interval. The identification results dynamic system with 5 poles approach, this approach can give dynamic model estimation for each mass experiment. For each dynamic model the frequency response evaluation is conducted as an alternative of shaker machine. This evaluation can give the relationship between input frequency and probability of overshoot in floating load deviation. And then the evaluation of the change of input-output deviation to the frequency is conducted for input frequency identification which can give negative phase shift. The results of the evaluation of the frequency response to load variation show that the prototype of suspended load backpack is only effective in reducing impact force in displacement oscillation in range 10-20 Hz. For use in real applications, it is necessary to adjust and perfect the structure and parameters of the spring suspension and support frame system.