Step-exchange strategy for balance control of a walking biped under a lateral impact

2014 ◽  
Vol 41 (5) ◽  
pp. 456-464
Author(s):  
Yeoun-Jae Kim ◽  
Joon-Yong Lee ◽  
Ju-Jang Lee
Keyword(s):  
External Force ◽  
Balance Control ◽  
Biped Robot ◽  
Conservation Equation ◽  
Hill Climbing ◽  
Lateral Impact ◽  
Content Type ◽  
Double Support ◽  
The Right ◽  
The Impact

Purpose – This paper aims to present a step-exchange strategy for balance control of a walking biped robot when a lateral impact acts suddenly. A step-out strategy has been recently proposed for balance control when an unknown lateral force acts to a biped robot during walking. This step-out strategy causes a robot to absorb the impact kinetic energy and efficiently maintain balance without falling down. Nevertheless, it was found that the previous strategies have drawbacks that the two foots should always be on the ground (double-support mode) after being balanced and the authors think it is difficult to continue walking after being balanced. Unlike the existing balance strategies, the proposed step-exchange strategy is to not only maintain balance but also to lift one leg in the air (single-support mode) after being balanced so that it is easy for a biped robot to keep walking after being balanced. Design/methodology/approach – In the proposed step-exchange strategy, forward Newton–Euler equation, angular momentum and energy conservation equation were derived. Hill-climbing algorithm is utilized for numerically finding a solution. To verify the proposed strategy, a biped robot by Open Dynamics Engine was stimulated, and experiments with a real biped robot (LRH-1) were also conducted. Findings – The proposed step-exchange strategy enables a walking biped robot under a lateral impact to keep balance and to keep a single-support mode after exchanging a leg. It is helpful for a biped robot to continue walking without any stop. It is found that the proposed step-exchange strategy can be applicable for maintaining balance even if a biped robot is moving. Even though this proposal seems immature yet, it is the first attempt to exchange the supporting foot itself. This strategy is very straightforward and intuitive because humans are also likely to exchange their supporting foot onto the opposite side when an unexpected force is acting. Research limitations/implications – The proposed step-exchange strategy described in this paper can be applicable in the situation when the external force is applied in the +Y direction, the left leg is the swing leg and the right leg is the stance leg, or it can also be applicable in the situation when the external force is applied in −Y direction, the right leg is the swing leg and the left leg is the stance leg (Figure 2 for ±Y force direction). If an impact force acts to the side of the swing leg, the other step-exchange strategy is needed. The authors are studying this issue as a future work. Originality/value – The authors have originated the proposed step-exchange strategy for balance control of a walking biped robot under lateral impact. The strategy is genuine and superior in comparison with the state-of-the-art strategy because not only can a biped robot be balanced but it can also easily continue walking by using the step-exchange strategy.

A force-resisting balance control strategy for a walking biped robot under an unknown, continuous force

Robotica ◽  
2014 ◽  
Vol 34 (7) ◽  
pp. 1495-1516
Author(s):  
Yeoun-Jae Kim ◽  
Joon-Yong Lee ◽  
Ju-Jang Lee
Keyword(s):  
External Force ◽  
Control Strategy ◽  
Balance Control ◽  
Biped Robot ◽  
Second Step ◽  
Double Support ◽  
Zero Moment ◽  
External Forces ◽  
Single Support Phase ◽  
Support Phase

SUMMARYIn this paper, we propose and examine a force-resisting balance control strategy for a walking biped robot under the application of a sudden unknown, continuous force. We assume that the external force is acting on the pelvis of a walking biped robot and that the external force in the z-direction is negligible compared to the external forces in the x- and y-directions. The main control strategy involves moving the zero moment point (ZMP) of the walking robot to the center of the robot's sole resisting the externally applied force. This strategy is divided into three steps. The first step is to detect an abnormal situation in which an unknown continuous force is applied by examining the position of the ZMP. The second step is to move the ZMP of the robot to the center of the sole resisting the external force. The third step is to have the biped robot convert from single support phase (SSP) to double support phase (DSP) for an increased force-resisting capability. Computer simulations and experiments of the proposed methods are performed to benchmark the suggested control strategy.

A Balance Control Strategy for a Walking Biped Robot under Unknown Lateral External Force using a Genetic Algorithm

2015 ◽  
Vol 12 (02) ◽  
pp. 1550021 ◽  
Author(s):  
Yeoun-Jae Kim ◽  
Joon-Yong Lee ◽  
Ju-Jang Lee
Keyword(s):  
Genetic Algorithm ◽  
External Force ◽  
Control Strategy ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Balance Control ◽  
Phase 1 ◽  
Biped Robot ◽  
Double Support ◽  
Support Phase

In this paper, we propose a force-resisting balance control strategy for a walking biped robot subject to an unknown continuous external force. We assume that the biped robot has 12 degrees of freedom (DOFs) with position-controlled joint motors, and that the unknown continuous external force is applied to the pelvis of the biped robot in the single support phase (SSP) walking gait. The suggested balance control strategy has three phases. Phase 1 is to recognize the application of an unknown external force using only zero moment point (ZMP) sensors. Phase 2 is to control the joint motors according to a method that uses a genetic algorithm and the linear interpolation technique. Against an external continuous force, the robot retrieves the pre-calculated solutions and executes the desired torques with interpolation performed in real time. Phase 3 is to make the biped robot move from the SSP to the double support phase (DSP), rejecting external disturbances using the sliding mode controller. The strategy is verified by numerical simulations and experiments.

Buyer-assisted lean intervention in supplier firms: a supplier development approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Imranul Hoque
Keyword(s):  
Financial Incentives ◽  
Large Scale ◽  
Qualitative Data ◽  
Research Approach ◽  
Capability Development ◽  
Content Type ◽  
Production Capability ◽  
Lean Tools ◽  
The Right ◽  
The Impact

PurposeThis study aims to investigate how buyer-assisted lean intervention in garment supplier factories affects garment suppliers' productivity and production capability development.Design/methodology/approachEmploying a qualitative research approach and a lean intervention design, a multiple case study method was adopted for this study. Quantitative data on productivity performance and qualitative data on production capability development were collected from a Danish buyer and their four corresponding garment suppliers. Collected data were analysed using standard lean measurement tools and qualitative data analysis techniques.FindingsThis study demonstrates that buyer-assisted lean intervention is a useful strategy for garment suppliers to enhance their productivity and production capability. However, suppliers need to select the right lean tools, ensure seriousness and commitment to lean initiatives, substantial involvement of top management and workers, arrange formal and informal training, provide performance-based financial/non-financial incentives and nurture a learning culture to facilitate suppliers' production capability development.Research limitations/implicationsThis study implemented few lean tools in a single sewing line in four supplier factories for a short intervention duration. Thus, there is a scope for future studies to investigate the impact of the lean intervention on a large scale.Practical implicationsThe findings of this study might bring new insights to the management of buyer and supplier firms concerning how buyers could involve in suppliers' lean intervention initiatives and what suppliers need to ensure to develop production capability.Originality/valueFor the first time, this study engaged a buyer in suppliers' lean intervention initiatives to improve productivity and production capability in the garment industry of a developing country.

Performance measurement and resource sharing among business sub-units in the presence of non-discretionary factors

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rita Shakouri ◽  
Maziar Salahi
Keyword(s):  
Resource Sharing ◽  
Content Type ◽  
Development Level ◽  
Proposed Model ◽  
Decision Making Unit ◽  
Efficiency Estimation ◽  
Overall Efficiency ◽  
And Performance ◽  
The Right ◽  
The Impact

Purpose This paper aims to apply a new approach for resource sharing and efficiency estimation of subunits in the presence of non-discretionary factors and partial impacts among inputs and outputs in the data envelopment analysis (DEA) framework. Design/methodology/approach First, inspired by the Imanirad et al.’s model (2013), the authors consider that each decision-making unit (DMU) may consist of several subunits, that each of which can be affected by non-discretionary inputs. After that, the Banker and Morey’s model (1996) is used for modeling non-discretionary factors. For measuring performance of several subunits, which can be considered as DMUs, the aggregate efficiency is suggested. At last, the overall efficiency is computed and compared with each other. Findings One of the important features of proposed model is that each output in this model applies discretionary input according to its need; therefore, the result of this study will make it easier for the managers to make better decisions. Also, it indicates that significant predictions of the development of the overall efficiency of DMUs can be based on observing the development level of subunits because of the influence of non-discretionary input. Therefore, the proposed model provides a more reasonable and encompassing measure of performance in participating non-discretionary and discretionary inputs to better efficiency. An application of the proposed model for gaining efficiency of 17 road patrols is provided. Research limitations/implications More non-discretionary and discretionary inputs can be taken into consideration for a better analysis. This study provides us with a framework for performance measures along with useful managerial insights. Focusing upon the right scope of operations may help out the management in improving their overall efficiency and performance. In the recent highway maintenance management systems, the environmental differences exist among patrols and other geotechnical services under the climate diverse. Further, in some cases, there might exist more than one non-discretionary factor that can have different effects on the subunits’ performance. Practical implications The purpose of this paper was to measure the performance of a set of the roadway maintenance crews and to analyze the impact of non-discretionary inputs on the efficiency of the roadway maintenance. The application of the proposed model, on the one hand, showed that each output in this model uses discretionary input according to its requirement, and on the other hand, the result showed that meaningful predictions of the development of the overall efficiency of DMUs can be based on observing the development level of subunits because of the impact of non-discretionary input. Originality/value Providing information on resource sharing by taking into account non-discretionary factors for each subunit can help managers to make better decisions to increase the efficiency.

scholarly journals Finding the right management approach in independent hotels

2019 ◽  
Vol 31 (7) ◽  
pp. 2862-2883 ◽  
Author(s):  
Alireza Nazarian ◽  
Peter Atkinson ◽  
Pantea Foroudi ◽  
Karen Dennis
Keyword(s):  
Leadership Style ◽  
Structural Equation ◽  
Management Approach ◽  
Snowball Sampling ◽  
Content Type ◽  
Organisational Effectiveness ◽  
Independent Hotels ◽  
The Right ◽  
Reward Mechanism ◽  
The Impact

Purpose This study aims to identify factors that managers can influence to improve effectiveness by examining the relationship between leadership and effectiveness in small and medium-sized independent hotels. Design/methodology/approach In total, 272 valid questionnaires were collected from managers of 83 small and medium-sized independent hotels in the Netherlands by using selective and snowball sampling techniques. A two-stage structural equation modelling approach was used to test the hypotheses. Findings Surprisingly, in contradiction to previous studies, neither transactional nor transformational leadership had a direct effect on organisational effectiveness. Instead, the effect was through the intervening variables of ability to acquire resources and reward mechanisms. Research limitations/implications The contradiction between this and previous studies may be due to the fact that constructs used in this study do not have the universal applicability that is customarily assumed and further investigation is needed. Practical implications This study suggests that managers in this type of hotel, first, should be adaptable in their leadership style and not rely on transactional leadership alone; second, managers must pay attention to resource acquisition; and third, managers must retain staff by using the right reward mechanism. Originality/value This study contributes to the literature of leadership and effectiveness in small and medium-sized independent hotels by being the first to focus on the impact of ability to acquire resources and reward mechanism. It also makes an important contribution to the growing body of hospitality literature that probes the supposed universal validity of organisational studies’ constructs.

Impact of bookshelf locations using eye-tracking methodology

2020 ◽  
Vol 41 (8/9) ◽  
pp. 617-629
Author(s):  
Sho Sato ◽  
Yukari Eto ◽  
Kotomi Iwaki ◽  
Tadashi Oyanagi ◽  
Yu Yasuma
Keyword(s):  
Eye Tracking ◽  
User Behavior ◽  
Public Library ◽  
Gaze Behavior ◽  
Content Type ◽  
User Behaviors ◽  
Significant Relationships ◽  
Vertical Location ◽  
The Right ◽  
The Impact

PurposeThis study aimed to understand better the user gaze behavior on bookshelves using eye-tracking technology.Design/methodology/approachAn eye-tracking experiment in a public library with 11 participants was performed. The impact of vertical shelf location of books on the number of times the books are looked at, the impact of horizontal location and the relationship between user behavior and location impact were examined by the findings.FindingsThe results showed that the vertical location of books has a significant impact on the number of times the books are looked at. More than 80% of the time spent looking at bookshelves was spent on books on the top to fourth rows. It was also revealed that the horizontal location of books has a little impact. Books located on the left side of shelves will be looked at significantly more often than those on the right side. No significant relationships between type of user behaviors and location impact were observed.Originality/valueThe study explored the impact of the vertical location of books on time spent looking at bookshelves using eye-tracking methodology. Few published studies do such experiments to address user gaze behavior on bookshelves. The study explored that the vertical location of books has a great impact, and horizontal location has a little impact on user gaze behavior.

Study shows psychological capital and work engagement mediate the impact of high-performance work systems (HPWS) on intentions to quit, creativity and extra-role performance

2019 ◽  
Vol 27 (7) ◽  
pp. 7-8
Keyword(s):  
Work Engagement ◽  
High Performance ◽  
Psychological Capital ◽  
Black Box ◽  
Role Performance ◽  
Employee Outcomes ◽  
Customer Contact ◽  
Content Type ◽  
The Right ◽  
The Impact

Purpose The researchers wanted to examine the mediating factors operating in the “black box” between HPWS and employee outcomes. Design/methodology/approach The authors obtained their data from a variety of customer-contact employees, such as front desk agents, food servers and concierges, in four and five-star hotels in the Romanian cities of Sibiu and Bucharest. They sent out questionnaires measuring psychological capital, such as self-reliance, hope, resilience and optimism, as well as work engagement, creative performance and extra-role performance. Supervisors were also asked their opinions. Findings The analysis of customer-contact employees and their supervisors in the Romanian hotel industry suggested that psychological capital and work engagement were the two most important factors operating in the “black box” between HPWS and employee outcomes. Originality/value There is great value for businesses in the conclusions of the research. It shows how critical it is to establish various HPWS programs that boost engagement, as well as indicating the importance of providing job security and designing recruitment processes that root out people with the right skills.

The impact of fair value estimates on audit fees: evidence from the financial sector in Jordan

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rateb Mohammad Alqatamin ◽  
Ernest Ezeani
Keyword(s):  
Positive Relationship ◽  
Stock Exchange ◽  
Random Effect ◽  
Audit Fees ◽  
Fair Value ◽  
Financial Information ◽  
Content Type ◽  
External Auditors ◽  
The Right ◽  
The Impact

PurposeThis study investigates the association between the estimates of fair value and external auditor's fees.Design/methodology/approachBased on a sample of 32 Jordanian financial companies listed on the Amman Stock Exchange (ASE) over the period 2005–2018. We employ random effect models to test our hypothesis.FindingsWe found a positive relationship between audit fees and the proportion of fair value assets, which implies that external auditors are more likely to spend more effort for complex estimates, thereby increasing audit fees. We examined the relationship between audit fees and three levels of fair value inputs and found a positive relationship between the level of effort spent on assessment of higher uncertainty fair value inputs and audit fees. The findings are consistent with the expectation that more audit effort is required in a highly regulated environment due to the possibility of a higher cost of litigation.Practical implicationsThe findings of this study could be beneficial for a number of users of financial information, such as investors, regulators, auditors. This group of users might consider the results of this study when they are using a company's financial information, and consequently, better able to make the right decisions.Originality/valueAlthough prior studies have researched fair value, no study to date among developing countries has investigated its relationship with audit fees. This study, therefore, provides new empirical evidence that the complexity and risk of fair value estimates significantly influences auditors' motivation to expend additional effort, resulting in higher audit cost.

Between flexibility and discipline in new product development: expertise as a boundary condition

2019 ◽  
Vol 37 (1) ◽  
pp. 33-49 ◽  
Author(s):  
Daniel Robey ◽  
Karl Hellman ◽  
Isabelle Monlouis ◽  
Kenneth Nations ◽  
Wesley J. Johnston
Keyword(s):  
Product Development ◽  
New Product Development ◽  
New Product ◽  
Market Definition ◽  
Content Type ◽  
Team Members ◽  
Award Winning ◽  
The Right ◽  
Cross Case Analysis ◽  
The Impact

Purpose The purpose of this paper is to study two aspects of new product development (NPD) success – the impact of learning and the impact of structure – are studied. Design/methodology/approach A multiple case study method within a single setting consisting of in-depth interviews of two teams that developed successful, award-winning products and two teams that developed unsuccessful products. Findings Case 1: flexibility and expertise permitted learning and radical redefinition of the product mid-project and commercial success. Case 2: flexibility enabled adding expertise which was instrumental in success, iterating permitted optimizing pricing. Case 3: flexibility led to focusing on technical issues to the exclusion of commercial viability. Case 4: flexibility led to skipping market definition and partnering with a particular customer whose situation was idiosyncratic. Cross-case analysis: flexibility in teams with both technical and commercial expertise yielded success. Flexibility permitted teams consisting of narrow experts to invest development resources in products with insufficient market. Research limitations/implications This paper argues that the right balance between structure and flexibility is dependent on the level of expertise of the members of the NPD project teams. However, getting this balance right is not a sufficient condition for NPD success. The cases were theoretically blocked to develop theoretical insight, but additional cases are needed for a strong test of theory. Practical implications The more experienced team members are, the more the project benefits from flexibility. Conversely, an inexperienced team will benefit from a more structured process. Projects require iteration. The dichotomy between structure and flexibility is false: the most expert teams benefit from some structure. The most inexperienced teams must employ flexibility to learn. Originality/value The analysis combines the virtues of the stage-gate school and the flexibility school previously thought mutually exclusive.

Architects and rural post-disaster housing: lessons from South India

2015 ◽  
Vol 6 (2) ◽  
pp. 206-224 ◽  
Author(s):  
Gertrud Tauber
Keyword(s):  
South India ◽  
Social Dynamics ◽  
Participant Observation ◽  
Indian Ocean Tsunami ◽  
Primary Data ◽  
Structured Interviews ◽  
Content Type ◽  
The Right ◽  
The Impact ◽  
Post Disaster

Purpose – This research aims to examine three housing projects implemented by local non-governmental organizations (NGOs) and planned by local architects after the Indian Ocean tsunami of 2004 in rural South India. The key to the acceptance of post-disaster houses lies in meeting the peoples’ wishes and needs, and in integrating local know-how into the course of the project process (a premise intensively discussed in theory). After the tsunami of 2004, many (NGOs) appointed architects, assuming that these professionals would be qualified to facilitate the implementation of people-oriented houses (and villages). However, the architects’ roles vary significantly, which had, as will be shown here, a considerable impact on the degree of success of the project. Design/methodology/approach – Primary data for this study were gathered through household questionnaires (110); informal interaction; participant-observation (work assignment: 2.5 years; field survey: 4 months); semi-structured interviews (NGO representatives, architects and engineers). Secondary literature was studied on post-disaster housing, building cultures and cultures of knowledge. Findings – This study reveals that, in the course of rural post-disaster reconstruction, there is a crying need to appoint the “right” personnel having, first of all, the capacity to comply with the social dynamics at project level, and, second, being able to address those aspects critical for the realization of people-oriented housing. Architects can be a valuable resource for both the NGO and the villagers. However, this paper shows that key to this is, among other considerations, a thorough understanding of the rural (building) culture, its abilities and requirements, the strategic interplay of various roles and abilities during the course of an intricate building process and the design of appropriate roles for adequately-skilled architects. Originality/value – To this date, the debate on the role of architects in the context of post-disaster housing has neglected to examine empirically the implications of appointing these professionals in rural post-disaster contexts. This paper addresses this imbalance and complements the existing corpus of work by examining the impact of different roles of architects on the degree of success of the project at village level.

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