Golf Swing Robot Research Articles

Robust Control of Golf Swing Robot Using Backstepping Based on Fuzzy Sliding-Mode and Super-Twisting Backstepping Sliding-Mode Algorithms

This paper focuses on trajectory tracking, robustness and stabilization of a golf swing robot which has been recently developed to simulate the ultra-high-speed swing motions of a golfer. The proposed control strategies are based on the Lyapunov stability theory and include Backstepping and Sliding-Mode Control based techniques. To attenuate the chattering phenomena caused by a discontinuous switching function and improve the dynamic response of the manipulator, a fuzzy system is used in this research; a Backstepping Sliding-Mode Controller (BSMC), a Backstepping Fuzzy Sliding-Mode Controller (BFSMC) and a Super-twisting Backstepping Sliding-Mode Controller (STBSMC) are used to evaluate the proposed hybrid controller’s BFSMC performance. The Lyapunov stability theory is used to guarantee the stability of the proposed closed-loop robot technique. Numerical simulations show the effectiveness of the proposed strategy based on the fuzzy logic mechanism under different disturbances and uncertainties.

A Knee-Guided Evolutionary Computation Design for Motor Performance Limitations of a Class of Robot With Strong Nonlinear Dynamic Coupling

Robots for high-speed manipulation require to produce motions beyond the performance limitations set by the traditional approaches. Recent results integrate the properties associated with dynamic coupling driving and structural mechanics to compute optimal smooth arm motions; however, when accelerating the convergence speed of potential solutions, those approaches cannot avoid premature convergence. In this article, we propose an autonomous motion planning method at the torque level for a class of robots considering multiple conflicting performance metrics. Specifically, we focus on the hyper dynamic manipulation of a golf swing robot using a knee-guided multiobjective optimization algorithm. Compared with traditional planning methods in position or velocity level, it can study motor performance limitations with strong nonlinear dynamic coupling beyond the motion limits designed by the manufacturers. First, the robot’s joint torque is approximated by the B-spline method using the solution at each iteration. Then, we transform the motion planning problem into a multiobjective optimization problem with soft constraints of torque limits and hard constraints of joint stops, and develop a knee-guided evolutionary algorithm to find the optimization solution with the quality tradeoffs between the scale of parameters and metrics. Finally, we conduct the simulation to demonstrate the dynamics performance of the golf swing robot. The results indicate that our approach can generate superior dynamics performance beyond limits with low energy consumption and high precision.

압축강도, 반발계수가 다른 골프공의 성능비교시험

The purpose of the study is to provide objective data on the performance of golf balls by comparing ball compression and coefficient of restitution(COR) using seven types of products. Seven types of golf balls weighed 45.442 to 45.711 g, while the outside diameter was measured at 42.703 to 42.773 mm, with a distribution of 0.59 % in weight and 0.16 % in diameter. As a result of measuring the outer diameter of a golf ball by increasing the compression load from 200 lb to 300 Ibrahim, the four-piece golf ball was altered by 0.600 mm and the three-piece golf ball was changed by 0.638 to 0.820 mm. The coefficient of restitution(COR) of golf balls tends to decrease to 0.852, 0.846 and 0.801 as the ball speed of firing was increased to 80, 85 and 125 mph. After measuring the deformation of a golf ball with a high-speed camera, the deformation of the ball was not related to coefficient of restitution and increased in cases of large changes in compressive strength. The results of the seven types of golf swing robot tests showed a ball speed of 2.3 mph, a total distance of 6.023 m, and a standard deviation of 1.4 % and 2.2 %. The difference in ball rotation was 361 rpm, which resulted in a relatively large standard deviation of about 14 %.

스윙 스피드에 따른 드라이버 샤프트의 변형이 골프볼의 궤적에 미치는 영향

This study was been focused on comparison of swing spot, ball trajectory, deflection of shaft with change of swing speed for two kind of shafts which have a different stiffness. Driver A(CPM=246) and Driver B(CPM=218) were joined to Golf Swing Robot, and then swing test was carried out at 80 mph, 90 mph, 100 mph for swing speed. An increase of swing speed resulted in a closing of face angle, an increasing of beginning velocity and carry of ball. As for deflection of shaft, that of Driver A increased toward swing direction with swing speed, and that of Driver B increased with swing speed but decreased in range of 100 mph. As for Droop of both Driver A and Driver B, it was not a significant difference in range of 80 mph, 90 mph, but there showed a significant difference in range of 100 mph. In comparison of carry between Driver A and Driver B at 100 mph swing speed, that of Driver A was longer than that of Driver B, because a deflecting direction of Driver A is same to the swing direction so dynamic energy of club head could be transferred more to golf ball than that of Driver B of which deflecting direction was opposite to the swing direction.

J1010305 ゴルフスイングのシミュレーションに関する研究 : スイングスピードがゴルフクラブのしなりに及ぼす影響

Golf is the sports that have been enjoyed by the people of a wide age group. The many golfers aim to get the high score and hope to getting the longer distance and to raising the ball speed with the golf club (Driver). And the improvement of the golf club head has been accomplished. In 2008, the upper limit of the coefficient of restitution of the golf club head was regulated. Therefore, the study of the golf club shaft comes to attract more attention. The authors already proposed the swing simulation referring the swing image of the golf swing robot. In the proposed swing simulation, the finite element model of golf club which consists of the golf club head and the laminated composite shaft is used. In this study, using the proposed swing simulation, the effect of the swing speed to the behavior of the swinging golf club shaft is clarified.

1P1-P02 三脚型ゴルフスイングロボットの姿勢安定制御(動作計画と制御の新展開(1))

1P1-P02 三脚型ゴルフスイングロボットの姿勢安定制御(動作計画と制御の新展開(1))

Optimizing Motion Planning for Hyper Dynamic Manipulator

Optimizing Motion Planning for Hyper Dynamic ManipulatorThis paper investigates the optimal motion planning for an hyper dynamic manipulator. As case study, we consider a golf swing robot which is consisting with two actuated joint and a mechanical stoppers. Genetic Algorithm (GA) technique is proposed to solve the optimal golf swing motion which is generated by Fourier series approximation. The objective function for GA approach is to minimizing the intermediate and final state, minimizing the robot's energy consummation and maximizing the robot's speed. Obtained simulation results show the effectiveness of the proposed scheme.

801 2次元スイング中のゴルフクラブの挙動解析

Composite materials have been employed in many sporting gears. Especially, laminated composite materials are used for the golf club shafts. The purpose of study is to present the two-dimensional swing simulation of the golf club refereeing the swing image of the golf swing robot to clarify the deflection of the swinging golf club shafts. Firstly, a finite element model of golf club which consists of the simplified golf club head and the laminated composite shaft is presented. And, it is proposed that the two-dimensional swing simulation of the golf clubs using the relationship between the time and the angular velocity of the grip of golf club estimated from the swing image of the golf swing robot. Next, from the results obtained by the proposed swing simulation, the validity of the grip position of the golf club is clarified. Finally, the effects of the stacking sequence of the golf club shaft and the swing speed to the deflection of the shaft during the swing are examined, respectively.

Motion planning of a golf swing robot

We report our studies of a new motion planning method for a two-link golf swing robot. We introduce two fundamental properties of manipulator dynamics: the time-reversal symmetry property and the pendulum property. The former is used to reverse the rest-to-point pre-impact swing (backswing and downswing) into a symmetric point-to-rest swing in time, and the latter is used to design a proportional-derivative plus gravity, joint and coupling torque compensation control algorithm to plan the reversed pre-impact swing and the point-to-rest follow-through swing. By using this method, accurate impact position and hitting speed control of the golf swing and low computational cost are achieved. The introduced properties hold true for general multi-revolute-joint planar manipulators and the proposed motion planning algorithm can be implemented on them too.

Identification of a golf swing robot using soft computing approach

Golf swing robots have been recently developed in an attempt to simulate the ultra high-speed swing motions of golfers. Accurate identification of a golf swing robot is an important and challenging research topic, which has been regarded as a fundamental basis in the motion analysis and control of the robots. But there have been few studies conducted on the golf swing robot identification, and comparative analyses using different kinds of soft computing methodologies have not been found in the literature. This paper investigates the identification of a golf swing robot based on four kinds of soft computing methods, including feedforward neural networks (FFNN), dynamic recurrent neural networks (DRNN), fuzzy neural networks (FNN) and dynamic recurrent fuzzy neural networks (DRFNN). The performance comparison is evaluated based on three sets of swing trajectory data with different boundary conditions. The sensitivity of the results to the changes in system structure and learning rate is also investigated. The results suggest that both FNN and DRFNN can be used as a soft computing method to identify a golf robot more accurately than FFNN and DRNN, which can be used in the motion control of the robot.

Development of a golf robot for simulating individual golfer’s swings

Golf robots are widely used by manufacturers for equipment testing as players are inconsistent and fatigue. Traditional golf swing robots have a ‘standard’ swing profile yet every golfer swings a club differently and needs equipment customised for their swing to perform optimally. Therefore, a robot is needed that can replicate different golfers’ swings to improve the development of customised equipment. This paper details the evaluation of a golf robot developed to enable biomechanical data measured from a golfer’s swing to be used to program the robot to recreate that swing. The angular motions of different golfers were accurately replicated by the robot although differences were observed in the shaft loading between golfers and the corresponding simulation.

Motion Control of a Golf Swing Robot

In this paper we discuss our simulation and empirical study of a golf swing motion controller for a two-link golf swing robot. We distinguish two variants of the whole golf swing termed as hitting problem and stopping problem. For the hitting problem arising from backswing and downswing, we map the task into the output of a target dynamic system—a harmonic oscillator—under energy control. For the stopping problem that arises from follow-through, we propose a Proportional plus Gravity and Coupling Torque Compensation (PGCTC) feedback controller. Preliminary simulation study shows the proposed controllers solve the hitting problem and the stopping problem respectively. The controllers are implemented on a physical robot. Experimental results indicate the robot is able to perform desired golf swing-backswing, downswing, and follow-through. We also give a preliminary analysis on the proposed method to understand its merits and weaknesses.

221 ゴルフスイングロボットによるゴルフクラブの物理パラメータ同定

221 ゴルフスイングロボットによるゴルフクラブの物理パラメータ同定

Impedance Control for a Golf Swing Robot to Emulate Different-Arm-Mass Golfers

Various golfers can play different golf swing motions even if they hold the same golf club. This phenomenon casts light on the significance of the dynamic interaction between the golfer’s arm and golf club. The dynamic interaction results in different swing motions, even if the robot has the same input torque of the shoulder joint as that of a golfer. Unfortunately, such influence has not been considered in the conventional control of a golf swing robot. An impedance control method is proposed for a golf swing robot to emulate different-arm-mass golfers in consideration of the dynamic interaction between human arm and golf club. Based on the Euler–Lagrange principle and assumed modes technique, a mathematical model of golf swing considering the shaft bending flexibility is established to simulate the swing motions of different-arm-mass golfers. The impedance control method is implemented to a prototype of golf swing robot composed of one actuated joint and one passive joint. The comparison of the swing motions of the robot and different-arm-mass golfers is made and the results show that the proposed golf swing robot with the impedance control method can emulate different-arm-mass golfers.

Shock and Vibration Control of a Golf-Swing Robot at Impacting the Ball

A golf swing robot is a kind of fast motion manipulator with a flexible link. A robot manipulator is greatly affected by Corioli's and centrifugal forces during fast motion. Nonlinearity due to these forces can have an adverse effect on the performance of feedback control. In the same way, ordinary state observers of a linear system cannot accurately estimate the states of nonlinear systems. This paper uses a state observer that considers disturbances to improve the performance of state estimation and feedback control. A mathematical model of the golf robot is derived by Hamilton's principle. A linear quadratic regulator (LQR) that considers the vibration of the club shaft is used to stop the robot during the follow-through action. The state observer that considers disturbances estimates accurate state variables when the disturbances due to Corioli's and centrifugal forces, and impact forces work on the robot. As a result, the performance of the state feedback control is improved. The study compares the results of the numerical simulations with experimental results.

Motion generation for hyper dynamic manipulation

Basic concept about how to realize hyper dynamic manipulation by a robot has been given by the authors in previous works. Based on the analysis results of human hyper dynamic manipulation, two key issues concerning the realization of hyper dynamic manipulation by an anthropomorphic mechanism, namely, utilization of dynamically coupled driving and structural joint stops, have been emphasized. Therefore, unlike that for conventional manipulators, our approach is to design and control a hyper dynamic manipulator based on the utilization of dynamically coupled driving and structural joint stops. Motion generation based on this approach is critical to the utilization of dynamically coupled driving and joint stops, and presents great difficulties. In this paper, a new method for motion generation is proposed, and its superior numerical stability achieved with high accuracy is shown by simulation results. Many meaningful and interesting results for the hyper dynamic manipulation for a two-joint manipulator are obtained in simulation. Moreover, the hyper dynamic manipulation is realized successfully by a prototype of a golf swing robot, designed based on the concept presented in this paper.

2P1-A05 ゴルフスイングロボットに関する研究 : 改善したストッパモデルによる運動制御(動作計画と制御の新展開)

2P1-A05 ゴルフスイングロボットに関する研究 : 改善したストッパモデルによる運動制御(動作計画と制御の新展開)

2P1-A04 ゴルフスイングロボットに関する研究 : エネルギー制御を用いた運動軌道の生成(動作計画と制御の新展開)

A golf swing robot which has a smart structure and enables high-speed swing based on dynamic coupling drive has been developed by authors. We have reported the feasibility of combining target dynamics and energy control to generate the golf swing trajectory from address position to impact position by now. In this paper, we apply the method to generate the whole swing trajectory and show its efficacy through experimental results.

DESIGN FOR HIGH DYNAMIC PERFORMANCE ROBOT BASED ON DYNAMICALLY COUPLED DRIVING AND JOINT STOPS

A new design approach is proposed for high dynamic performance robots, such as robots performing high-speed dynamic motions. This method is based on the utilization of dynamically coupled driving and joint stops. In the method, the dynamic performance index (DPI) formulated by the desired maximum motion specifications and the boundary conditions on initial/final configurations are combined to form a design index (DI) first. Then a dexterous mechanism consisting of very light actuators and links is initially designed under an assumption of utilizing dynamically coupled driving and joint stops. By increasing the load capabilities of the actuators step by step, an iterative process of searching for the solution of DI=0 with minimal torque needs is implemented to validate and improve the initial design. This process yields a robot that is lighter than conventional robots and capable of performing dynamic motions more efficiently by utilizing dynamically coupled driving and joint stops. Based on the method, a two-link golf swing robot performing high-speed swings is designed. Simulation results indicate the method can reduce the needs for the torque and power as compared with conventional design methods. The experiment clearly illustrates the merits of the method.

Multiple modulation torque planning for a new golf-swing robot with a skilful wrist turn

A new golf-swing robot that included a feed-forward controller in the shoulder joint and a passive wrist joint was suggested in previous studies to more closely model a skilful golfer. In this study, multiple modulation torque planning for a new golf-swing robot that is capable of modelling a skilful golfer’s swing with a delayed wrist turn was analytically examined. The twostep modulation torque included the effects of whole-body motion on shoulder acceleration, which improved the efficiency index of the swing motion and the club head speed at impact with a correctly timed wrist turn. In addition, it was demonstrated that the optimum moment of inertia and optimum design of club shaft rigidity for several types of golfers could be determined by torque planning in a virtual performance test.