1,296 research outputs found
Actuators and sensors for application in agricultural robots: A review
In recent years, with the rapid development of science and technology, agricultural robots have gradually begun to replace humans, to complete various agricultural operations, changing traditional agricultural production methods. Not only is the labor input reduced, but also the production efficiency can be improved, which invariably contributes to the development of smart agriculture. This paper reviews the core technologies used for agricultural robots in non-structural environments. In addition, we review the technological progress of drive systems, control strategies, end-effectors, robotic arms, environmental perception, and other related systems. This research shows that in a non-structured agricultural environment, using cameras and light detection and ranging (LiDAR), as well as ultrasonic and satellite navigation equipment, and by integrating sensing, transmission, control, and operation, different types of actuators can be innovatively designed and developed to drive the advance of agricultural robots, to meet the delicate and complex requirements of agricultural products as operational objects, such that better productivity and standardization of agriculture can be achieved. In summary, agricultural production is developing toward a data-driven, standardized, and unmanned approach, with smart agriculture supported by actuator-driven-based agricultural robots. This paper concludes with a summary of the main existing technologies and challenges in the development of actuators for applications in agricultural robots, and the outlook regarding the primary development directions of agricultural robots in the near future
Exploitation of environmental constraints in human and robotic grasping
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We investigate the premise that robust grasping performance is enabled by exploiting constraints present in the environment. These constraints, leveraged through motion in contact, counteract uncertainty in state variables relevant to grasp success. Given this premise, grasping becomes a process of successive exploitation of environmental constraints, until a successful grasp has been established. We present support for this view found through the analysis of human grasp behavior and by showing robust robotic grasping based on constraint-exploiting grasp strategies. Furthermore, we show that it is possible to design robotic hands with inherent capabilities for the exploitation of environmental constraints
MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics
El libro de actas recoge las aportaciones de los autores a través de los correspondientes artículos a la Dinámica de Sistemas Multicuerpo y la Mecatrónica (Musme). Estas disciplinas se han convertido en una importante herramienta para diseñar máquinas, analizar prototipos virtuales y realizar análisis CAD sobre complejos sistemas mecánicos articulados multicuerpo. La dinámica de sistemas multicuerpo comprende un gran número de aspectos que incluyen la mecánica, dinámica estructural, matemáticas aplicadas, métodos de control, ciencia de los ordenadores y mecatrónica. Los artículos recogidos en el libro de actas están relacionados con alguno de los siguientes tópicos del congreso:
Análisis y síntesis de mecanismos
; Diseño de algoritmos para sistemas mecatrónicos
; Procedimientos de simulación y resultados
; Prototipos y rendimiento
; Robots y micromáquinas
; Validaciones experimentales
; Teoría de simulación mecatrónica
; Sistemas mecatrónicos
; Control de sistemas mecatrónicosUniversitat Politècnica de València (2011). MUSME 2011 4 th International Symposium on Multibody Systems and Mechatronics. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/13224Archivo delegad
Design and control of components-based integrated servo pneumatic drives
On-off traditional pneumatic drives are most widely used in industry offering
low-cost, simple but flexible mechanical operation and relatively high power to
weight ratio. For a period of decade from mid 1980's to 1990's, some initiatives
were made to develop servo pneumatic drives for most sophisticated
applications, employing purpose-designed control valves for pneumatic drives
and low friction cylinders. However, it is found that the high cost and complex
installation have discouraged the manufacturer from applying servo pneumatic
drives to industrial usage, making them less favourable in comparison to their
electric counterpart. This research aims to develop low-cost servo pneumatic
drives which are capable of point-to-point positioning tasks, suitable for
applications requiring intermediate performance characteristics. In achieving
this objective, a strategy that involves the use of traditional on-off valve, simple
control algorithm and distributed field-bus control networks has been adopted,
namely, the design and control of Components-based Integrated Pneumatic
Drives (CIPDs).
Firstly, a new pneumatic actuator servo motion control strategy has been
developed. With the new motion control strategy, the processes of positioning a
payload can be achieved by opening the control valve only once. Hence, lowspeed
on-off pneumatic control valves can be employed in keeping the cost low,
a key attraction for employing pneumatic drives. The new servo motion control
strategy also provides a way of controlling the load motion speed mechanically.
Meanwhile, a new PD-based three-state closed-loop control algorithm also has
been developed for the new control scheme. This control algorithm provides a
way of adapting traditional PID (Proportional Integral Derivative) control
theories for regulating pneumatic drives. Moreover, a deceleration control
strategy has been developed so that both high-speed and accurate positioning
control can be realised with low cost pneumatic drives. Secondly, the effects of system parameters on the transient response are studied. In assisting the analysis, a second order model is developed to encapsulate the velocity response characteristics of pneumatic drives to a step input signal. Stability
analyses for both open loop and closed-loop control have also been carried out
for the CIPDs with the newly developed motion control strategy. Thirdly, a
distributed control strategy employing Lon Works has been devised and
implemented, offering desirable attributes, high re-configurability, low cost and
easy in installation and maintenance, etc to keep with the traditional strength for
using pneumatic drives. By applying this technology, the CIPDs become
standard components in "real" and "virtual" design environments. A remote
service strategy for CIPDs using TCP/IP communication protocol has also been
developed.
Subsequently a range of experimental verifications has been carried out in the
research. The experimental study of high-speed motion control indicates that the
deceleration control strategy developed in the research can be an effective
method in improving the behaviour of high speed CIPDs. The verification of
open loop system behaviour of CIPDs shows that the model derived is largely
indicative of the likely behaviour for the system considered, and the steady state
velocity can be estimated using the Velocity Gain Kv. The evaluation made on a
pneumatically driven pick-and-place machine has also confirmed that the
system setup, including wiring, tuning, and system reconfiguration can be
achieved in relative ease. This pilot study reveals the potential for employing
CIPDs in building highly flexible cost effective manufacturing machines. It can
thus be concluded that this research has developed successfully a new
dimension and knowledge in both theoretical and practical terms in building
low-cost servo pneumatic drives, which are capable of point-to-point
positioning through employing traditional on-off pneumatic valves and
actuators and through their integration with distributed control technology
(LonWorks) by adopting a component-based design paradigm
Is the purchasing behavior of suburban millennials affected by social media marketing? empirical evidence from Malaysia
An abundance of social media marketing research has been conducted on urban consumers, but notably, only a few attempts have been made in understanding suburban consumers, especially on low involvement products. Due to this lack of research, this study aims to understand how social media marketing influences online purchasing behavior of Millennials in suburban areas of low involvement products. This study adapts the theory of uses and gratification to justify online purchasing behavior among Millennials. This study also seeks to understand the role of consumer engagement as a moderator. A total of 384 respondents, aged between 18-35 years old who have experience purchasing low involvement products through online websites took part in this study. The results indicated that three (3) social media marketing dimensions, namely online communities, entertainment, and perceived trust, had significant effects on the Millennials’ online purchasing behavior of low involvement products. However, consumer engagement did not moderate the relationship between social media marketing dimensions and the online purchasing behavior of Millennials regarding low involvement products. This study contributes to the integration of two new dimensions, namely entertainment and perceived trust in the concept of social media marketing. The findings have supported the uses and gratification theory, whereby Millennials in suburban areas inclined to choose their favorite online websites to fulfill their needs and wants. This finding also helped marketing managers to design their websites to cater to the unique trends of Millennials. Apart from that, this study also contributes to the marketing literature in relation to the space of low involvement products, consumer engagement, and Millennials' online purchasing behavior
Inverse Kinematics to a Stewart Platform
Mechanical systems in motion type parallel structures are solid, fast and accurate. Between mobile systems parallel the best known and used system is that of a Stewart platforms, as being and the oldest system, quickly, solid and accurate. The paper presents a few main elements of the Stewart platforms. In the case where a motto element consists of a structure composed of two elements in a relative movement from the point of view of the train of propulsion and especially in the dynamic calculations, it is more convenient to represent the motto element as a single moving item. The paper presents an exact, original analytical geometry method for determining the kinematic and dynamic parameters of a parallel mobile structure. Compared with other methods already known, the presented method has the great advantage of being an exact analytical method of calculation and not one iterative-approximately
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