scholarly journals Guidance Law Design for a Class of Dual-Spin Mortars

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Qing-wei Guo ◽  
Wei-dong Song ◽  
Yi Wang ◽  
Zhi-cai Lu
Keyword(s):  
Degrees Of Freedom ◽  
Vertical Plane ◽  
Variable Parameter ◽  
Ease Of Use ◽  
Gps Receiver ◽  
Guidance Law ◽  
Lateral Plane ◽  
The Cost ◽  
Guidance Laws ◽  
Geomagnetic Measurements

To minimize the cost and maximize the ease of use, a class of dual-spin mortars is designed which only rely on GPS receiver and geomagnetic measurements. However, there are some problems to be solved when the range is small, such as low correction authority and trajectory bending. Guidance law design for this mortar is detailed. Different guidance laws were designed for the ascending and descending segments, respectively. By taking variable parameter guidance law in the vertical plane and using compensation in the lateral plane, the problems mentioned above were resolved. Roll angle resolving algorithms with geomagnetic measurements were demonstrated and the experiment results proved to be effective. In order to verify the effectiveness, Seven-Degrees-of-Freedom (7-DOF) rigid ballistic model were established and hardware in the loop simulation was introduced. After the transform function of the actuator was obtained, the control model of the shell was improved. The results of the Monte Carlo simulation demonstrate that the guidance law is suitable and the mortar can be effectively controlled.

Optimal cooperative guidance with guaranteed miss distance in three-body engagement

2016 ◽  
Vol 232 (3) ◽  
pp. 492-504 ◽  
Author(s):  
Feng Fang ◽  
Yuan-Li Cai
Keyword(s):  
Linear Quadratic ◽  
Control Effort ◽  
Guidance Law ◽  
Cooperative Guidance ◽  
The One ◽  
Three Body ◽  
The Cost ◽  
Miss Distance ◽  
Penalty Weight ◽  
Guidance Laws

The three-body engagement where a target aircraft protects itself by using a cooperative defender missile to intercept an attacking missile is investigated. It is formulated as a constrained linear quadratic optimal problem. Two different optimal cooperative guidance laws for the target and defender are proposed in two cooperation schemes. Since any control effort to reduce the miss distance to smaller than missile’s lethal radius is wasted, the guidance laws are derived to achieve an upper bound on the missile–defender miss distance. In the two-way cooperation scheme, the target and the defender act as a team. How the target makes a trade-off between aiding the defender and evading the missile is investigated by considering both the missile–target zero-effort miss distance and the control effort into the cost function. Without the penalty weight on the missile–target zero-effort miss distance, the two-way minimum control effort guidance laws are available. In the one-way cooperation scheme, the target uses a known evasion strategy independently. The optimal cooperative guidance law is derived for minimizing the control effort of the defender. Simulation results show that these proposed guidance laws can provide a specified missile–defender miss distance and save the control effort compared with the zero-miss-distance guidance law. Two-way cooperation scheme outperforms one-way cooperation scheme.

Time-energy optimal guidance strategy for realistic interceptor using pseudospectral method

2020 ◽  
Vol 42 (13) ◽  
pp. 2361-2371 ◽  
Author(s):  
Arunava Banerjee ◽  
Mashuq Nabi ◽  
T. Raghunathan
Keyword(s):  
Optimal Control ◽  
Pseudospectral Method ◽  
Two Dimensional ◽  
Energy Usage ◽  
Proportional Navigation ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Legendre Pseudospectral Method ◽  
The Cost ◽  
Guidance Laws

This paper proposes the use of Legendre pseudospectral method (PSM) to obtain the optimal guidance strategy for a two-dimensional interceptor problem. An optimal control problem is formulated that addresses the conflicting objective of minimizing the energy usage, along with minimizing the time taken by missile to capture the target. The PSM-based guidance strategy is compared with other conventional guidance laws such as pure proportional navigation (PPN) guidance law and also evolutionary algorithm inspired differential evolution tuned proportional navigation (DEPN) guidance law. A scheme by which the PSM guidance strategy can be applied online is also included in this paper. The cost function value and the interception time indicates the superiority of the PSM-based guidance strategy.

Trajectory shaping guidance law design using constraint-combining multiplier

2021 ◽  
pp. 095441002098637
Author(s):  
Min-Guk Seo ◽  
Chang-Hun Lee ◽  
Tae-Hun Kim
Keyword(s):  
Design Method ◽  
Impact Angle ◽  
State Variables ◽  
Flight Trajectory ◽  
Potential Significance ◽  
Guidance Law ◽  
Terminal Constraints ◽  
The Impact ◽  
Guidance Laws ◽  
Impact Angle Constraint

A new design method for trajectory shaping guidance laws with the impact angle constraint is proposed in this study. The basic idea is that the multiplier introduced to combine the equations for the terminal constraints is used to shape a flight trajectory as desired. To this end, the general form of impact angle control guidance (IACG) is first derived as a function of an arbitrary constraint-combining multiplier using the optimal control. We reveal that the constraint-combining multiplier satisfying the kinematics can be expressed as a function of state variables. From this result, the constraint-combining multiplier to achieve a desired trajectory can be obtained. Accordingly, when the desired trajectory is designed to satisfy the terminal constraints, the proposed method directly can provide a closed form of IACG laws that can achieve the desired trajectory. The potential significance of the proposed result is that various trajectory shaping IACG laws that can cope with various guidance goals can be readily determined compared to existing approaches. In this study, several examples are shown to validate the proposed method. The results also indicate that previous IACG laws belong to the subset of the proposed result. Finally, the characteristics of the proposed guidance laws are analyzed through numerical simulations.

Design of finite-time guidance law based on observer and head-pursuit theory

2021 ◽  
pp. 095441002098456
Author(s):  
Chenqi Zhu
Keyword(s):  
Finite Time ◽  
Three Dimensional ◽  
Hypersonic Vehicle ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Reaching Law ◽  
Guidance Law ◽  
Fast Power ◽  
Simulation Results ◽  
Guidance Laws

In order to improve the guiding accuracy in intercepting the hypersonic vehicle, this article presents a finite-time guidance law based on the observer and head-pursuit theory. First, based on a two-dimensional model between the interceptor and target, this study applies the fast power reaching law to head-pursuit guidance law so that it can alleviate the chattering phenomenon and ensure the convergence speed. Second, target maneuvers are considered as system disturbances, and the head-pursuit guidance law based on an observer is proposed. Furthermore, this method is extended to a three-dimensional case. Finally, comparative simulation results further verify the superiority of the guidance laws designed in this article.

3D Nonlinear Guidance Law for Bank-to-Turn Missile

2011 ◽  
Vol 317-319 ◽  
pp. 727-733
Author(s):  
Shuang Chun Peng ◽  
Liang Pan ◽  
Tian Jiang Hu ◽  
Lin Cheng Shen
Keyword(s):  
Three Dimensional ◽  
Lyapunov Theory ◽  
Line Of Sight ◽  
Rate Model ◽  
Guidance Law ◽  
Terminal Constraints ◽  
Guidance Laws ◽  
3D Guidance ◽  
Guidance Model ◽  
Vector Description

A new three-dimensional (3D) nonlinear guidance law is proposed and developed for bank-to-turn (BTT) with motion coupling. First of all, the 3D guidance model is established. In detail, the line-of-sight (LOS) rate model is established with the vector description method, and the kinematics model is divided into three terms of pitching, swerving and coupling, then by using the twist-based method, the LOS direction changing model is built for designing the guidance law with terminal angular constraints. Secondly, the 3D guidance laws are designed with Lyapunov theory, corresponding to no terminal constraints and terminal constraints, respectively. And finally, the simulation results show that the proposed guidance law can effectively satisfy the guidance precision requirements of BTT missile.

A comparative study of qualitative immunochemical screening assays for the combined measurement of T-2/HT-2 in cereals and cereal-based products

2011 ◽  
Vol 4 (4) ◽  
pp. 385-394 ◽  
Author(s):  
J. Meneely ◽  
F. Ricci ◽  
S. Vesco ◽  
M. Abouzied ◽  
M. Sulyok ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Low Cost ◽  
Ease Of Use ◽  
The Other ◽  
Accuracy And Precision ◽  
Cost Implications ◽  
Electrochemical Array ◽  
The Cost ◽  
Preparation Techniques ◽  
Speed Of Analysis

Many different immunochemical platforms exist for the screening of naturally occurring contaminants in food from the low cost enzyme linked immunosorbent assays (ELISA) to the expensive instruments such as optical biosensors based on the phenomenon of surface plasmon resonance (SPR). The primary aim of this study was to evaluate and compare a number of these platforms to assess their accuracy and precision when applied to naturally contaminated samples containing HT-2/T-2 mycotoxins. Other important factors considered were the speed of analysis, ease of use (sample preparation techniques and use of the equipment) and ultimately the cost implications. The three screening procedures compared included an SPR biosensor assay, a commercially available ELISA and an enzymelinked immunomagnetic electrochemical array (ELIME array). The qualitative data for all methods demonstrated very good overall agreements with each other, however on comparison with mass spectrometry confirmatory results, the ELISA and SPR assay performed slightly better than the ELIME array, exhibiting an overall agreement of 95.8% compared to 91.7%. Currently, SPR is more costly than the other two platforms and can only be used in the laboratory whereas in theory both the ELISA and ELIME array are portable and can be used in the field, but ultimately this is dependent on the sample preparation techniques employed. Sample preparative techniques varied for all methods evaluated, the ELISA was the most simple to perform followed by that of the SPR method. The ELIME array involved an additional clean-up step thereby increasing both the time and cost of analysis. Therefore in the current format, field use would not be an option for the ELIME array. In relation to speed of analysis, the ELISA outperformed the other methods.

scholarly journals Optimal Path-Following Guidance with Generalized Weighting Functions Based on Indirect Gauss Pseudospectral Method

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Qi Chen ◽  
Xugang Wang ◽  
Jing Yang
Keyword(s):  
Degrees Of Freedom ◽  
Optimal Path ◽  
Pseudospectral Method ◽  
Path Following ◽  
Control Cost ◽  
Weighting Functions ◽  
Guidance Law ◽  
Computational Performance ◽  
Gauss Pseudospectral Method ◽  
Virtual Target

An indirect Gauss pseudospectral method based path-following guidance law is presented in this paper. A virtual target moving along the desired path with explicitly specified speed is introduced to formulate the guidance problem. By establishing a virtual target-fixed coordinate system, the path-following guidance is transformed into a terminal guidance with impact angle constraints, which is then solved by using indirect Gauss pseudospectral method. Meanwhile, the acceleration dynamics are modeled as the first-order lag to the command. Using the receding horizon technique a closed-loop guidance law, which considers generalized weighting functions (even discontinuous) of both the states and the control cost, is derived. The accuracy and effectiveness of the proposed guidance law are validated by numerical comparisons. A STM32 Nucleo board based on the ARM Cortex-M7 processor is used to evaluate the real-time computational performance of the proposed indirect Gauss pseudospectral method. Simulations for various types of desired paths are presented to show that the proposed guidance law has better performance when compared with the existing results for pure pursuit, a nonlinear guidance law, and trajectory shaping path-following guidance and provides more degrees of freedom in path-following guidance design applications.

Design and development of a novel 3D-printed non-metallic self-locking prosthetic arm for a forequarter amputation

2020 ◽  
pp. 030936462094829 ◽  
Author(s):  
Trevor Binedell ◽  
Eugene Meng ◽  
Karupppasamy Subburaj
Keyword(s):  
Computer Aided Design ◽  
Ease Of Use ◽  
Prosthetic Design ◽  
Forequarter Amputation ◽  
Digital Scanning ◽  
Survey Results ◽  
3D Printed ◽  
And Function ◽  
The Cost ◽  
Aided Design

Background: Upper limb, in particular forequarter amputations, require highly customised devices that are often expensive and underutilised. Objectives: The objective of this study was to design and develop a comfortable 3D-printed cosmetic forequarter prosthetic device, which was lightweight, cool to wear, had an elbow that could lock, matched the appearance of the contralateral arm and was completely free of metal for a specific user’s needs. Study Design: Device design. Technique: An iterative user-centred design approach was used for digitising, designing and developing a functional 3D-printed prosthetic arm for an acquired forequarter amputation, while optimising the fit and function after each prototype. Results: The cost of the final arm was 20% less expensive than a traditionally-made forequarter prostheses in Singapore. The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) 2.0 survey was administered, with results indicating that the 3D-printed arm was preferred due to its overall effectiveness, accurate size, ease of use and suspension. However, durability had a lower score, and the weight of the arm was 100 g heavier than the user’s current prosthesis. The technique described resulted in a precise fitting and shaped forequarter prosthesis for the user. Using the user’s feedback in the iterations of the design resulted in improved QUEST survey results indicating the device was effective, easy to use, perceived as lighter and more secure than the user’s traditionally-made device. Conclusion: A fully customised cosmetic forequarter prosthesis was designed and developed using digital scanning, computer-aided design modelling and 3D printing for a specific user. These technologies enable new avenues for highly complex prosthetic design innovations.

Generalized explicit guidance with optimal time-to-go and realistic final velocity

2019 ◽  
Vol 233 (13) ◽  
pp. 4926-4942
Author(s):  
Sabyasachi Mondal ◽  
Radhakant Padhi
Keyword(s):  
Optimal Solution ◽  
Optimal Time ◽  
Optimal Solutions ◽  
Final Velocity ◽  
Velocity Magnitude ◽  
Guidance Law ◽  
Optimal Guidance ◽  
Input Parameters ◽  
The Cost

This paper presents an approach to compute the optimal time-to-go and final velocity magnitude in the Generalized Explicit (GENEX) guidance. Time-to-go and final velocity magnitude are two critical input parameters in GENEX guidance implementation. Optimal time-to-go selects that optimal solution which yields less cost compared to the costs yielded by other optimal solutions. In addition to it, the input of realistic final velocity lowers the cost further. These developments relax the existing limitations of GENEX, thereby making this optimal guidance law more optimal, effective and generic.

scholarly journals An IoT Smart Broiler Farming Model for Low Income Farmers

2018 ◽  
Vol 6 (3) ◽  
pp. 95
Author(s):  
Hazael Phiri ◽  
Douglas Kunda ◽  
Jackson Phiri
Keyword(s):  
Low Income ◽  
Cost Model ◽  
Low Cost ◽  
Ease Of Use ◽  
Climate Control ◽  
Proposed Model ◽  
Zigbee Protocol ◽  
Gsm Network ◽  
The Cost ◽  
Broiler House

<p class="Abstract"><span lang="EN-US">The coming of Internet of things (IoT) brings opportunities for the deploying of wireless sensor networks. One area of deployment is smart poultry farming to improve the quality and security of chicken varieties that include broilers. The quality of broilers produced is dependent on the environment in which the broilers are kept. In addition, the revenue of the farmer is guaranteed if theft of stock is prevented. The current methods farmers use are labour intensive and time consuming as they are manual. Leveraging the features of IoT and sensors can help to monitor the environment and ensure adverse conditions are reported for farmers to take action before they harm the livestock. Incorporating intruder detection when monitoring conditions in the environment can also prevent stock theft and that can increase the income obtained by farmers. For such a system to be widely adopted by low income farmers, the cost should be low compared commercially available climate control systems that are meant for commercial farmers. The system should also provide ease of use for less technically skilled farmers, reduce the time taken by farmers to take action in controlling theft and conditions in the environment and be accessible from any location other than the broiler house. In this paper, we propose a low-cost model that can be used to monitor conditions in the environment of a broiler house and send the values to the farmer in real-time. The proposed model is based on open source microcontrollers, ZigBee protocol, GSM network, mobile applications and cloud computing. </span></p>

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