Optimization of flight distance and robustness in the discus

Kazuya Seo, Koji Shimoyama, Ken Ohta, Yuji Ohgi, Yuji Kimura

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

This paper describes the optimal flight of a discus. Two objective functions are considered. One is the flight distance, and the other is robustness. Robustness is defined as insensitivity to deviations from the local optimal release conditions. The aim of the optimization is to maximize both flight distance and robustness. There are ten control and design variables, which include variables concerned with the skill of the thrower and with the design of the equipment. It was found that there is a trade-off between flight distance and robustness. It was also found that lower drag is preferable in the first half of flight, and greater lift and drag are preferable in the latter half of flight for the world record throw of 77 m. In order to do this, the initial angle between the velocity vector and the discus planform should be negative at the launch, even if the initial lift acts vertically downward. The attitude of the discus should be inclined at launch. The discus rolls with time during the flight, so that the discus planform becomes almost in the horizontal plane in the latter half of the flight. Lower mass is good for achieving longer flight distance, but conversely, mass should be slightly greater for robustness.

Original languageEnglish
Pages (from-to)55-65
Number of pages11
JournalSports Engineering
Volume18
Issue number1
DOIs
Publication statusPublished - 2015

Fingerprint

Equipment Design
Planforms
Drag
Robustness
Optimization
Insensitivity
Inclined
Horizontal
Deviation
Objective function
Trade-offs
Maximise
Angle

Keywords

  • Concurrent optimization
  • Discus
  • Flight distance
  • Robustness

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Biomedical Engineering
  • Modelling and Simulation
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Optimization of flight distance and robustness in the discus. / Seo, Kazuya; Shimoyama, Koji; Ohta, Ken; Ohgi, Yuji; Kimura, Yuji.

In: Sports Engineering, Vol. 18, No. 1, 2015, p. 55-65.

Research output: Contribution to journalArticle

Seo, Kazuya ; Shimoyama, Koji ; Ohta, Ken ; Ohgi, Yuji ; Kimura, Yuji. / Optimization of flight distance and robustness in the discus. In: Sports Engineering. 2015 ; Vol. 18, No. 1. pp. 55-65.
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