자율주행자동차의 Jerk에 따른 평균주행속도 변화 분석

정승원,문영준,황기연 한국교통연구원 2018 交通硏究 Vol.25 No.1

Jerk is a differential value of accelerating or decelerating speed that influences on driving stability and riding comfort. Since ordinary drivers feel difficult to control jerks when they adjust speed, it is rarely used in road traffic. By applying the concept of jerk that affects driving stability, the study analyzed average vehicle speed changes both on main and entry-exit sections in a freeway according to varying entrainment rate and density of Automated Vehicles (AVs). This study finds, in main freeway sections, that low jerk with low entrainment rate in a high density showed a high average vehicle speed, while in entry and exit sections showed a low jerk high average vehicle speed regardless of entrainment rate. As jerk increases, the gap between acceleration and deceleration widens and a deceleration becomes more frequent due to shock wave. Since ordinary cars are rarely affected by AVs under a low traffic density, it is assumed that average vehicle speed of high jerk is higher. By contrast, ordinary cars are more or less affected by AVs due to indispensable conflicts in entry and exit sections. Overall the application of jerk into AVs does not have great impacts on traffic flow. So that when jerk is limited in consideration of driving stability and riding comfort for passengers, it has limited influence over general traffic flow. Furthermore, it can be asserted that loosening limitations of jerks for AV can promote traffic flow more smoothly or improve driving capability rather than driving stability. Jerk는 가속도의 미분 값으로 주행안정성 및 승차감에 영향을 준다. 일반적인 운전자가 가감속할 때 Jerk를 컨트롤하는 것은 어렵기 때문에 도로교통에서 자주 활용되는 개념은 아니며, 철도나 승강기에서 활용하는 개념이다. 자율주행자동차는 조향 및 가속 장치를 자동화하여 운전자의 역할의 일부를 수행하는 기술로서, Jerk의 개념 적용이 가능하다. 자율주행자동차는 Jerk의 제한을 낮춰서 승차감을 향상시킬 수 있고, 반대로 주행속도와 주행성을 고려하여 Jerk의 제한을 높일 수도 있다. 다만 자율주행자동차와 일반 자동차가 혼재된 교통류에서 자율주행자동차의 Jerk의 제한을 어떻게 두는가에 따라 교통흐름의 부정적인 영향도 있을 수 있다는 우려가 따른다. 이에 본 연구에서는 자율주행자동차의 Jerk로 인해 일반 자동차와 전체 교통류의 흐름에 어떤 영향을 주는지 분석하였다. 분석방법으로 행위자기반모형 시뮬레이션 툴인 Netlogo를 이용하여 시뮬레이션 분석을 수행하였다. 기본구간과 진입출구간, 밀도와 자율주행자동차의 혼입율에 따른 다양한 시나리오를 설정하고, 각 시뮬레이션 분석 결과를 통해 자율주행자동차의 Jerk 영향을 분석하였다. 분석 결과 기본구간에서는 저혼입율일수록 고밀도일 때 낮은 Jerk의 평균주행속도가 높게 분석되었고, 진입출구간에서는 혼입율과 상관없이 저밀도일 때 낮은 Jerk의 평균주행속도가 높게 분석되었다. 즉, 승차감이나 주행안정성을 고려하여 Jerk를 반영하여도 일반자동차나 전체 교통류에 큰 영향을 미치지 않으며, 경우에 따라서는 평균주행속도가 높아질 수도 있다. 따라서 자율주행자동차에 Jerk를 반영하여 주행안정성을 향상시킬 수 있으며, 반대로 Jerk의 제한을 여유있게 두어 주행성을 향상시킬 수도 있을 것으로 판단된다.

ORIGINAL : Correlation Analysis between Dance Experience and Smoothness of Dance Movement by Using Three Jerk-Based Quantitative Methods

( Yang Sun Park ) 한국운동역학회 2016 한국운동역학회지 Vol.26 No.1

Objective: The aim of this study is to investigate the association between dance experience and smoothness of hand trajectory during dance by using three jerk-based quantitative methods (integrated squared jerk, mean squared jerk, and dimensionless jerk). Methods: Eleven Korean traditional dancers whose experience of dancing ranged from 5 years to 20 years participated in this study. Dancers performed the Taeguksun motion in Korea traditional dance. Six infrared cameras were used to capture the movement of the hands of the dancers. The smoothness of hand movement was calculated using three jerk-based methods. Results: With regard to the smoothness of the right hand, dance experience was significantly correlated with dimensionless jerk (r=0.656, p=0.028), while dance experience was not significantly correlated with integrated squared jerk (r=0.581, p=0.552) and mean squared jerk. With regard to the smoothness of the left hand, there was no correlation between dance experience and any of the three jerk values. Conclusion: Our results showed that individuals with more dance experience performed the task more smoothly. This study suggests that dimensionless jerk should be used as a predictor for smoothness in dance movement. Thus, our results support the idea that smoothness is an aspect of movement quantity distinct from speed and distance.

Correlation Analysis between Dance Experience and Smoothness of Dance Movement by Using Three Jerk-Based Quantitative Methods

박양선 한국운동역학회 2016 한국운동역학회지 Vol.26 No.1

Objective: The aim of this study is to investigate the association between dance experience and smoothness of hand trajectory during dance by using three jerk-based quantitative methods (integrated squared jerk, mean squared jerk, and dimensionless jerk). Methods: Eleven Korean traditional dancers whose experience of dancing ranged from 5 years to 20 years participated in this study. Dancers performed the Taeguksun motion in Korea traditional dance. Six infrared cameras were used to capture the movement of the hands of the dancers. The smoothness of hand movement was calculated using three jerk-based methods. Results: With regard to the smoothness of the right hand, dance experience was significantly correlated with dimensionless jerk (r=0.656, p=0.028), while dance experience was not significantly correlated with integrated squared jerk (r=0.581, p=0.552) and mean squared jerk. With regard to the smoothness of the left hand, there was no correlation between dance experience and any of the three jerk values. Conclusion: Our results showed that individuals with more dance experience performed the task more smoothly. This study suggests that dimensionless jerk should be used as a predictor for smoothness in dance movement. Thus, our results support the idea that smoothness is an aspect of movement quantity distinct from speed and distance.

Correlation Analysis between Dance Experience and Smoothness of Dance Movement by Using Three Jerk-Based Quantitative Methods

Park, Yang Sun Korean Society of Sport Biomechanics 2016 한국운동역학회지 Vol.26 No.1

Objective: The aim of this study is to investigate the association between dance experience and smoothness of hand trajectory during dance by using three jerk-based quantitative methods (integrated squared jerk, mean squared jerk, and dimensionless jerk). Methods: Eleven Korean traditional dancers whose experience of dancing ranged from 5 years to 20 years participated in this study. Dancers performed the Taeguksun motion in Korea traditional dance. Six infrared cameras were used to capture the movement of the hands of the dancers. The smoothness of hand movement was calculated using three jerk-based methods. Results: With regard to the smoothness of the right hand, dance experience was significantly correlated with dimensionless jerk (r=0.656, p=0.028), while dance experience was not significantly correlated with integrated squared jerk (r=0.581, p=0.552) and mean squared jerk. With regard to the smoothness of the left hand, there was no correlation between dance experience and any of the three jerk values. Conclusion: Our results showed that individuals with more dance experience performed the task more smoothly. This study suggests that dimensionless jerk should be used as a predictor for smoothness in dance movement. Thus, our results support the idea that smoothness is an aspect of movement quantity distinct from speed and distance.

최소저크궤적과 X축-스웨이를 이용한 4족 보행로봇의 안정적 걸음새 연구

이동구,신우현,김태정,이정호,이영석,황헌,최선 한국정보전자통신기술학회 2019 한국정보전자통신기술학회논문지 Vol.12 No.2

In this paper, three theories for improving the stability of quadruped robot are presented. First, the Minimum-Jerk Trajectory is used to optimize the leg trajectory. Second, we compare the newly proposed sine wave and the conventional LSM in this paper based on the Jerk value. Third, we calculate the optimum stride of the sway through repetitive robot simulation using ADAMS-MATLAB cosimulation. Through the above process, the improvement of the robot walking is compared with the existing theory. First, the average gradient of the point where the leg trajectory changes rapidly was reduced from at least 1.2 to 2.9 by using the Minimum-Jerk targetory for the movement of the body and the end of the leg during the first walk, thereby increasing the walking stability. Second, the average Jerk was reduced by 0.019 on the Z-axis, 0.457 on the X-axis, and 0.02, 3D on the Y-axis by 0.479 using the Sin wave type sways presented in this paper, rather than the LSM(Longitude Stability Margin) method. Third, the length of the optimal stride for walking at least the Jerk value was derived from the above analysis, and the 20cm width length was the most stable. 본 논문에서는 4족복 보행 로봇의 주행 안정성을 개선하기 위한 3가지 이론을 제시한다. 첫 번째는 Minimum-Jerk Trajectory를 이용하여 다리궤적을 최적화 시킨다. 두 번째는 본 논문에서 새롭게 제시한 사인파와 기존의 방식인 LSM을 Jerk값에 근거하여 비교한다. 셋째는 ADAMS-MATLAB co-simulation을 이용하여 반복적인 로봇 시뮬레이션을 통해 스웨이의 최적 보폭을 계산한다. 위의 과정을 통해 로봇의 보행 개선점을 기존의 이론과 비교하여 나타내었다. 첫 번째로 정 보행시 몸체와 타원형태의 다리 끝의 움직임에 Minimum-Jerk trajectory를 사용하여 다리 궤적이 급격하게 변하는 지점의 평균 기울기를 최소 1.2에서 최대 2.9까지 감소시켜 지면에 다리 끝점이 도달할 때 충격을 최소화하여 안정성을 증가 하였다. 두 번째로 기존 LSM(Longitudinal Stability Margin)기법과 본 논문에서 제시한 사인파형 Sway를 사용하여 비교한 결과 평균 Jerk를 Z축에서 0.019, X축에서 0.457, Y축에서 0.02, 3D는 0.479만큼 감소 시켰다. 특히 X축 Jerk는 크게 감소 하였다. 셋째로 로봇이 최소 Jerk 값으로 보행하기 위한 최적의 보폭의 길이를 상기 분석을 통해 도출하였으며 그 결과 20cm보폭 길이가 가장 안정적이었다.

정규 저크(Normalized Jerk)를 이용한 태권도 돌려차기 동작 분석

조임형(Lim Hyeong Cho),강성철(Seong Chul Kang),강신배(Sin Bae Kang),박석(Sok Park),김태완(Tae Wan Kim),고석곤(Suk Gon Go),권문석(Moon Seok Kwon) 한국사회체육학회 2012 한국사회체육학회지 Vol.0 No.49

The purpose of this study was to evaluate the round-house kick of Teakwondo and to compare between elite and novice Teakwondo players using the normalized jerk method. MATLAB v6.5(Mathworks Inc., USA) was employed to analyze the normalized jerk. Fourteen male subjects who had no musculo-skeletal diseases were participated and were classified into two groups(7 elite and 7 non-elite Teakwondo players). While all subjects performed the round-house kick, the height of target set up based on the center of trunk position, respectively. In this study, independent t-test (elite and non-elite) was applied to obtain the differences of normalized jerk value between the two groups. Significance level was set as p=.05. The forward backward and upward downward normalized jerk values of the kicking foot COM(center of mass) were found to be significantly different between elite and non-elite groups in the maximum knee flexion phase. Significant difference was seen in the upward downward normalized jerk value of the kicking foot COM from maximum knee flexion to impact between elite and non-elite groups(p<.05). The forward backward and upward downward normalized jerk values of the kicking foot COM were found to be significantly different between elite and non-elite groups during overall round-house kicking phase(p<.05). The left-side right-side and upward downward normalized jerk values of the whole body COM(center of mass) were found to be significantly different between elite and nonelite groups in the maximum knee flexion phase(p<.05). Significant difference was seen in the left-side right-side normalized jerk value of the kicking whole body COM from maximum knee flexion to impact between elite and non-elite groups(p<.05). The normalized jerk values of upward downward were found to be significantly different between elite and non-elite groups during overall round-house kicking phase(p<.05).

스포츠심리학 : 골프 칩샷 기술의 제어 특성: Normalized jerk의 적합성

박승하(SeungHaPark),이승민(SeungMinLee) 한국체육학회 2005 한국체육학회지 Vol.44 No.6

The normalized jerk, absolute jerk standardized relative to movement time and distance, have been accepted as the index of smoothness for evaluating the quality of movement in single- and/or planar two-joint movement. The purpose of this study was to determine if the variable of normalized jerk is appropriate as index of the movement smoothness in performing complex sport task such as chip shot in golf. We calculated the normalized jerk value of two end-points, the left wrist and the toe of club's head, and examined it's difference as function of skill level and hits/misses. Eighteen golfers, 9 experts and 9 non-experts, participated in the study. Each participant performed the chip shot at 8m distant from the hole until getting at least three hits and three misses. The results indicated the downswing of expert golfers was faster than that of non-expert golfers, but there were no differences in the swing duration between two skill levels in backswing and follow through. The normalized jerk value of left wrist was lower than that of club's head, regardless of swing phases. From the results of normalized jerk across swing phases, we confirmed expert golfers characterized the smoothness of movement in downswing among swing phases, and that the smoothness of swing in y- and z-direction was important for successful chip shot. In conclusion, we suggest that the variable of normalized jerk can be used as the index of smoothness in complex sport skill, but we should to step the process for identifying the validity of normalized jerk by the further studies.

Jerk-Constrained Time-Optimal Control of a Positioning Servo

Raymond Shieh,Yu-Sheng Lu 제어로봇시스템학회 2010 제어로봇시스템학회 국제학술대회 논문집 Vol.2010 No.10

This paper presents a jerk-constrained time-optimal control (JCTOC) method for a positioning servo. While high jerk, the derivative of acceleration with respect to time, can cause problems such as vibrations and high wear to mechanical parts, it is then important to limit the maximum jerk in many control applications. Many trajectory planning methods have been proposed, limiting the maximum jerk during the optimized planning of the desired path. Distinct from the previous path-planning methods that yield jerk-constrained ideal trajectories only, the approach proposed in this paper directly controls the jerk of the plant while guaranteeing minimum-time performance under the specified jerk constraint. Simulation studies of the JCTOC compared with the conventional PD controller have been conducted, demonstrating that the proposed control requires less control effort and also offers the time-optimal response with admissible jerk.

Global Minimum-Jerk Trajectory Planning of Space Manipulator

Panfeng Huang,Yangsheng Xu,Bin Liang 대한전기학회 2006 International Journal of Control, Automation, and Vol.4 No.4

A novel approach based on genetic algorithms (GA) is developed to find a global minimum-jerk trajectory of a space robotic manipulator in joint space. The jerk, the third derivative of position of desired joint trajectory, adversely affects the efficiency of the control algorithms and stabilization of whole space robot system and therefore should be minimized. On the other hand, the importance of minimizing the jerk is to reduce the vibrations of manipulator. In this formulation, a global genetic-approach determines the trajectory by minimizing the maximum jerk in joint space. The planning procedure is performed with respect to all constraints, such as joint angle constraints, joint velocity constraints, joint angular acceleration and torque constraints, and so on. We use an genetic algorithm to search the optimal joint inter-knot parameters in order to realize the minimum jerk. These joint inter-knot parameters mainly include joint angle and joint angular velocities. The simulation result shows that GA-based minimum-jerk trajectory planning method has satisfactory performance and real significance in engineering.

초음파 센서를 이용한 담적(痰積)진단시스템의 설계와 응답특성

李均正(Qyoun-Jung Lee),李瑢欽(Yong-Heum Lee),申泰民(Tae-Min Shin) 대한전기학회 2006 전기학회논문지 D Vol.55 No.4

Dam jerk causes a chronic stomach disorder. The number of the patient of the Dam jerk increase in these days. However, there are no objective and Quantitative study for a diagnosis of Dam jerk. Therefore, we designed diagnosis system using ultrasonic response signal for a diagnosis of Dam jerk. It was used to collect the response signal that is reflected at Dam jerk region of the abdominal. And then, the response signal at the Dam jerk region is 20% higher than the normal region. In the result, we could prove the reliability of the system.