Dynamic Bat-Control of a Redundant Ball Playing Robot

This thesis shows a control algorithm for coping with a ball batting task for an entertainment robot. The robot is a three jointed robot with a redundant degree of freedom and its name is Doggy . Doggy because of its dog-like costume. Design, mechanics and electronics were developed by us. DC-motors control the tooth belt driven joints, resulting in elasticities between the motor and link. Redundancy and elasticity have to be taken into account by our developed controller and are demanding control tasks. In this thesis we show the structure of the ball playing robot and how this structure can be described as a model. We distinguish two models: One model that includes a flexible bearing, the other does not. Both models are calibrated using the toolkit Sparse Least Squares on Manifolds (SLOM) - i.e. the parameters for the model are determined. Both calibrated models are compared to measurements of the real system. The model with the flexible bearing is used to implement a state estimator - based on a Kalman filter - on a microcontroller. This ensures real time estimation of the robot states. The estimated states are also compared with the measurements and are assessed. The estimated states represent the measurements well. In the core of this work we develop a Task Level Optimal Controller (TLOC), a model-predictive optimal controller based on the principles of a Linear Quadratic Regulator (LQR). We aim to play a ball back to an opponent precisely. We show how this task of playing a ball at a desired time with a desired velocity at a desired position can be embedded into the LQR principle. We use cost functions for the task description. In simulations, we show the functionality of the control concept, which consists of a linear part (on a microcontroller) and a nonlinear part (PC software). The linear part uses feedback gains which are calculated by the nonlinear part. The concept of the ball batting controller with precalculated feedback gains is evaluated on the robot. This shows successful batting motions. The entertainment aspect has been tested on the Open Campus Day at the University of Bremen and is summarized here shortly. Likewise, a jointly developed audience interaction by recognition of distinctive sounds is summarized herein. In this thesis we answer the question, if it is possible to define a rebound task for our robot within a controller and show the necessary steps for this

Prediction and Situational Option Generation in Soccer

Paul Ward, Michigan Technological University Naturalistic models of decision making, such as the Recognition- Primed Decision (RPD) model (e.g., Klein, Calderwood, & Clinton-Cirocco, 1986; Klein, 1997), suggest that as individuals become more experienced within a domain they automatically recognize situational patterns as familiar which, in turn, activates an associated situational response. Typically, this results in a workable course of action being generated first, and subsequent options generated only if the initial option proves ineffective

Proceedings of Mathsport international 2017 conference

Proceedings of MathSport International 2017 Conference, held in the Botanical Garden of the University of Padua, June 26-28, 2017. MathSport International organizes biennial conferences dedicated to all topics where mathematics and sport meet. Topics include: performance measures, optimization of sports performance, statistics and probability models, mathematical and physical models in sports, competitive strategies, statistics and probability match outcome models, optimal tournament design and scheduling, decision support systems, analysis of rules and adjudication, econometrics in sport, analysis of sporting technologies, financial valuation in sport, e-sports (gaming), betting and sports

The Effects Of Various Warm-Up Devices on Bat Velocity and Trajectory in Collegiate Baseball Players

Purpose: The purpose of this study was to examine the effects of various weighted warm-up devices on standard baseball bat velocity and trajectory in collegiate baseball players. Methods: Three, right-handed hitters (mean age= 19.3yrs ±1.5yrs; height= 1.74m±.13m; mass=81kg ±20.4kg; baseball experience=14.2 ±1.3) volunteered for this study. Maximal bat velocity was obtained by swinging the 30oz standard bat for the control condition. Participants were then instructed to perform a general and specific warm-up with each of the weighted bats (standard bat with 16oz donut ring (46oz total) and standard bat with 24oz power sleeve (54oz total)) on separate days. Following the warm-up procedures, participants were instructed to swing 3 times with the 30oz standard bat for maximal velocity while impacting the ball resting on the tee located belt-high and in the middle of home plate.Results: No significant differences were revealed by Shewart Chart method for baseball bat velocity or trajectory. Also, it was observed that all participants swung the bat at its lowest point in its trajectory for all conditions. Conclusion: Based upon no changes in the dependent variables in the population tested, Division II collegiate athletes can choose any of the warm-up devices investigated because no deleterious effects were observed

The Effects Of Various Warm-Up Devices on Bat Velocity and Trajectory in Collegiate Baseball Players

Purpose: The purpose of this study was to examine the effects of various weighted warm-up devices on standard baseball bat velocity and trajectory in collegiate baseball players. Methods: Three, right-handed hitters (mean age= 19.3yrs ±1.5yrs; height= 1.74m±.13m; mass=81kg ±20.4kg; baseball experience=14.2 ±1.3) volunteered for this study. Maximal bat velocity was obtained by swinging the 30oz standard bat for the control condition. Participants were then instructed to perform a general and specific warm-up with each of the weighted bats (standard bat with 16oz donut ring (46oz total) and standard bat with 24oz power sleeve (54oz total)) on separate days. Following the warm-up procedures, participants were instructed to swing 3 times with the 30oz standard bat for maximal velocity while impacting the ball resting on the tee located belt-high and in the middle of home plate.Results: No significant differences were revealed by Shewart Chart method for baseball bat velocity or trajectory. Also, it was observed that all participants swung the bat at its lowest point in its trajectory for all conditions. Conclusion: Based upon no changes in the dependent variables in the population tested, Division II collegiate athletes can choose any of the warm-up devices investigated because no deleterious effects were observed

Toward Simulation-Based Training Validation Protocols: Exploring 3d Stereo with Incremental Rehearsal and Partial Occlusion to Instigate and Modulate Smooth Pursuit and Saccade Responses in Baseball Batting

“Keeping your eye on the ball” is a long-standing tenet in baseball batting. And yet, there are no protocols for objectively conditioning, measuring, and/or evaluating eye-on-ball coordination performance relative to baseball-pitch trajectories. Although video games and other virtual simulation technologies offer alternatives for training and obtaining objective measures, baseball batting instruction has relied on traditional eye-pitch coordination exercises with qualitative “face validation”, statistics of whole-task batting performance, and/or subjective batter-interrogation methods, rather than on direct, quantitative eye-movement performance evaluations. Further, protocols for validating transfer-of-training (ToT) for video games and other simulation-based training have not been established in general ― or for eye-movement training, specifically. An exploratory research study was conducted to consider the ecological and ToT validity of a part-task, virtual-fastball simulator implemented in 3D stereo along with a rotary pitching machine standing as proxy for the live-pitch referent. The virtual-fastball and live-pitch simulation couple was designed to facilitate objective eye-movement response measures to live and virtual stimuli. The objective measures 1) served to assess the ecological validity of virtual fastballs, 2) informed the characterization and comparison of eye-movement strategies employed by expert and novice batters, 3) enabled a treatment protocol relying on repurposed incremental-rehearsal and partial-occlusion methods intended to instigate and modulate strategic eye movements, and 4) revealed whether the simulation-based treatment resulted in positive (or negative) ToT in the real task. Results indicated that live fastballs consistently elicited different saccade onset time responses than virtual fastballs. Saccade onset times for live fastballs were consistent with catch-up saccades that follow the smooth-pursuit maximum velocity threshold of approximately 40-70˚/sec while saccade onset times for virtual fastballs lagged in the order of 13%. More experienced batters employed more deliberate and timely combinations of smooth pursuit and catch-up saccades than less experienced batters, enabling them to position their eye to meet the ball near the front edge of home plate. Smooth pursuit and saccade modulation from treatment was inconclusive from virtual-pitch pre- and post-treatment comparisons, but comparisons of live-pitch pre- and post-treatment indicate ToT improvements. Lagging saccade onset times from virtual-pitch suggest possible accommodative-vergence impairment due to accommodation-vergence conflict inherent to 3D stereo displays

The assessment of movement demands and neuromuscular fatigue in female softball players

Softball has experienced an increase in worldwide popularity over the last 15 years, and it is expected to rise following the reinstatement of softball as an Olympic sport in 2021. Previous softball research has primarily focused on the biomechanical characteristics of its athletes. However, there is a current lack of research concerning the movement demands occurring in gameplay and the development of neuromuscular fatigue in softball players during sportspecific movements, training sessions, or in competition play. Prior research has demonstrated that a majority of power generated during a bat swing or overhand throw comes from the lower body, with the hip musculature playing an essential role in stabilisation and kinetic energy transmission. Understanding the development of neuromuscular fatigue, particularly in the hip musculature of softball athletes, will allow coaches and sport scientists to optimise training sessions, athlete monitoring techniques, and recovery methods. Accordingly, the overall aims of this thesis were to 1) describe the movement demands of female softball players during defensive and offensive gameplay, with a focus on the frequency and duration of movements occurring and differences between positional groups; 2) determine the reliability of the ForceFrame Hip Strength Testing System in assessing hip and shoulder strength of female softball players unaccustomed to isolated joint isometric measures; 3) assess changes in isometric hip strength in female softball players caused by a repeated batting protocol; and 4) compare changes in isometric strength of female softball players in training and game settings. The outcomes of this thesis will help to establish a description of the movement demands of softball games, which may optimise future softball training and recovery methods. Additionally, data gathered in this thesis will provide a solid foundation for conceptualising neuromuscular fatigue in softball players. These results will thus allow for a greater understanding of athlete preparation. Study one determined that softball is primarily composed of low intensity activities, like standing or walking, with intermittent periods of high intensity activity (e.g. sprinting, bat swings, high intensity throws). The cumulative effect of these high intensity activities across game durations of two hours or greater, compact tournament schedules and environmental factors may amplify neuromuscular fatigue. Study two concluded that the ForceFrame was a reliable tool in assessing hip and shoulder isometric strength in female diamond-sport athletes, potentially providing sport scientists with a suitable alternative to handheld dynamometers in field-based isometric testing. Study three documented changes in electromyographic amplitude and median frequency, isometric hip strength, and batted ball velocity of female softball players during a repeated batting protocol. Results indicate repeated batting can lead to neuromuscular fatigue and underscores the importance of routine monitoring of softball players in settings with limited recovery. Results of study four demonstrated significant levels of fatigue following softball training and gameplay, as well as evidence of cumulative fatigue in softball players following several games during a multi-day tournament. The results of this study provide the groundwork for determining an appropriate balance between competition-level training and adequate recovery