Design and Fabrication of a Multi-Material Compliant Flapping Wing Drive Mechanism for Miniature Air Vehicles

Author(s):  
Wojciech Bejgerowski ◽  
John W. Gerdes ◽  
Satyandra K. Gupta ◽  
Hugh A. Bruck ◽  
Stephen Wilkerson

Successful realization of a flapping wing micro air vehicle (MAV) requires development of a light weight drive mechanism converting the rotary motion of the motor into flapping motion of the wings. Low weight of the drive mechanism is required to maximize the payload and battery capacity. In order to make flapping wing MAVs attractive in search, rescue, and recovery missions, they should be disposable from the cost point of view. Injection molded compliant drive mechanisms are an attractive design option to satisfy the weight, efficiency and cost requirements. In the past, we have successfully used multi-piece molding to create mechanisms utilizing distributed compliance for smaller MAVs. However, as the size of the MAV increases, mechanisms with distributed compliance exhibit excessive deformation. Therefore localizing rather than distributing the compliance in the mechanism becomes a more attractive option. Local compliance can be realized through multimaterial designs. A multi-material injection molded mechanism additionally offers reduction in the number of parts. This paper describes an approach for determining the drive mechanism shape and size that meets both the functional design and multi-material molding requirements. The design generated by the approach described in this paper was utilized to realize a flapping wing MAV with significant enhancements in the payload capabilities.

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Wojciech Bejgerowski ◽  
Arvind Ananthanarayanan ◽  
Dominik Mueller ◽  
Satyandra K. Gupta

Successful realization of a flapping wing micro-air vehicle (MAV) requires development of a light weight drive mechanism that can convert the continuous rotary motion of the motor into oscillatory flapping motion of the wings. The drive mechanism should have low weight to maximize the payload and battery capacity. It should also have high power transmission efficiency to maximize the operational range and to minimize weight of the motor. In order to make flapping wing MAVs attractive in search, rescue, and recovery efforts, they should be disposable from the cost point of view. Injection molded compliant drive mechanisms are an attractive design option because of manufacturing scalability and reduction in the number of parts. However, realizing compliant drive mechanism using injection molding requires use of multipiece multigate molds. Molding process constraints need to be considered during the design stage to successfully realize the drive mechanism. This paper describes an approach for determining the drive mechanism shape and size that meets both the design and molding requirements. The novel aspects of this work include (1) minimizing the number of mold pieces and (2) the use of sacrificial shape elements to reduce the impact of the weld-lines on the structural performance. The design generated by the approach described in this paper was utilized to realize an operational flapping wing MAV.


Author(s):  
A. Sholokhova ◽  
O. Tsibernaja ◽  
V. Mykhaylenko ◽  
J. Burlakovs ◽  
V. Kuusemets ◽  
...  

A landfill is a large bioreactor, in the body of which landfill gases are generated due to anaerobic degradation of organic material. According to European legislation, the emission of methane, one of the landfill gases, should be kept to a minimum as methane is a greenhouse gas and has a significant impact on our climate. With large volumes, methane can be used for energy production, but if the collection is uneconomic, an attractive option would be to cover the landfill with a bioactive layer to degrade methane in-situ. In operational Uikala sanitary landfill, Estonia, where active gas collection system exists, it was found that uncaptured gas could be degraded in bioactive cover layer. To check whether such cover layer could be built from fine fraction after mechanical biological treatment (MBT), two experimental cells were constructed (0-20 mm and 0-40 mm fractions). The paper presents the design of experimental cells, a description of materials for construction and construction process, and preliminary results. Measurement system was installed in both cells: gas wells at eight depths and on three locations on surface. Three-level lysimeters were installed to determine water balance. Research is planned for two years with monthly gas sampling. The objective of the work is proving which of the MBT fractions, 0-20 or 0-40 mm, function better for methane degradation. Confirmation of the methane degradation efficiency in fine MBT fraction is important not only from the ecological point of view. The use of a fine fraction as a material for methane degradation layer would reduce the cost of processing this fraction and become a good example to a circular economy since the landfill would be recultivated using its own resources.


The article focuses on the problem of the lack of objective evaluation of space-planning arrangement of buildings as a creative approach of the architect to the performing of functional tasks by the object. It is proposed to create a methodology for assessing the functional of space-planning solutions of buildings on the basis of numerical simulation of functional processes using the theory of human flows. There is a description of the prospects of using this method, which makes it possible to increase the coefficient of compactness, materials and works saving, more efficient use of space, reduce the cost of the life cycle of the building, save human forces and time to implement the functional of the building. The necessary initial data for modeling on the example of shopping and shopping-entertainment centers are considered. There are three main tasks for algorithmization of the functional of shopping centers. The conclusion is made about necessity of development of a method for objective assessment of buildings from the point of view of ergonomics of space-planning decisions based on the study of human behavior in buildings of different purposes.


Author(s):  
Vitaly Lobas ◽  
◽  
Elena Petryaeva ◽  

The article deals with modern mechanisms for managing social protection of the population by the state and the private sector. From the point of view of forms of state regulation of the sphere of social protection, system indicators usually include the state and dynamics of growth in the standard of living of the population, material goods, services and social guarantees for the poorly provided segments of the population. The main indicator among the above is the state of the consumer market, as one of the main factors in the development of the state. Priority areas of public administration with the use of various forms of social security have been identified. It should be emphasized that, despite the legislative conflicts that exist today in Ukraine, mandatory indexation of the cost of living is established, which is associated with inflation. Various scientists note that although the definition of the cost of living index has a well-established methodology, there are quite a lot of regional features in the structure of consumption. All this is due to restrictions that are included in the consumer basket of goods and different levels of socio-economic development of regions. The analysis of the establishment and periodic review of the minimum consumer budgets of the subsistence minimum and wages of the working population and the need to form state insurance funds for unforeseen circumstances is carried out. Considering in this context the levers of state management of social guarantees of the population, we drew attention to the crisis periods that are associated with the market transformation of the regional economy. In these conditions, there is a need to develop and implement new mechanisms and clusters in the system of socio-economic relations. The components of the mechanisms ofstate regulation ofsocial guarantees of the population are proposed. The deepening of market relations in the process of reforming the system of social protection of the population should be aimed at social well-being.


ROBOT ◽  
2011 ◽  
Vol 33 (3) ◽  
pp. 366-370 ◽  
Author(s):  
Pengcheng CHI ◽  
Weiping ZHANG ◽  
Wenyuan CHEN ◽  
Hongyi LI ◽  
Kun MENG ◽  
...  

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 305
Author(s):  
Juan Yan ◽  
Marietta Haffner ◽  
Marja Elsinga

Inclusionary housing (IH) is a regulatory instrument adopted by local governments in many countries to produce affordable housing by capturing resources created through the marketplace. In order to assess whether it is efficient, scholarly attention has been widely focused on its evaluation. However, there is a lack of studies evaluating IH from a governance perspective. Since IH is about involving private actors in affordable housing production, the governance point of view of cooperating governmental and non-governmental actors governing society to achieve societal goals is highly relevant. The two most important elements of governance—actors and interrelationships among these actors—are taken to build an analytical framework to explore and evaluate the governance of IH. Based on a research approach that combines a literature review and a case study of China, this paper concludes that the ineffective governance of Chinese IH is based on three challenges: (1) The distribution of costs and benefits across actors is unequal since private developers bear the cost, but do not enjoy the increments of land value; (2) there is no sufficient compensation for developers to offset the cost; and (3) there is no room for negotiations for flexibility in a declining market. Given that IH is favored in many Chinese cities, this paper offers the policy implications: local governments should bear more costs of IH, rethink their relations with developers, provide flexible compliance options for developers, and perform differently in a flourishing housing market and a declining housing market.


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