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Technical Paper
2014-09-28
David B. Antanaitis, Heewook Lee
An area of brake system design that has remained continually resistant to objective, computer model based predictive design and has instead continued to rely on empirical methods and prior history, is that of sizing the brake pads to insure satisfactory service life and fade resistance of the friction material. Despite advances in CAE tools and methods, the ever-intensifying pressures of shortened vehicle development cycles, and the loss of prototype vehicle properties, there is still considerable effort devoted to vehicle-level testing on public roads using "customer-based" driving cycles to validate brake pad service life. Furthermore, there does not appear to be a firm, objective means of designing the required pad volume into the calipers early on - there is still much reliance on prior experience. This paper builds upon previous work by GM [1], where short duration, objective vehicle and dyno tests were combined with a computer model to allow for accurate pad service life prediction without vehicle tests, and expands it into a methodology combining CAE (CFD), computer modeling, objective friction material characterization data, to enable confident sizing of the brake pads very early in the vehicle development process.
Technical Paper
2014-09-28
Jongsung Kim, Chjhoon Jo, Yongsik kwon, Jae Seung Cheon, Soung Jun Park, Gab Bae Jeon, Jaehun Shim
Electro-Mechanical Brake (EMB) is the brake system that is actuated by the electrical energy and the motor rotation. It has similar design with Electro-Mechanical Parking Brake (EPB). It uses the gear multiplication structure for the enough torque and screw/nut mechanism for changing rotational movement to linear. The differences with EPB are screw/nut and motor type and some specification of the inner parts because the needed performance of the service braking like braking time is much higher than EPB, and usually EMB includes the force sensor for controlling the actuator and solenoid-lever structure for EPB function. The highly responsive and independent brake actuators lead to enhanced controllability which should result in not only better basic braking performance, but also improvements in various active braking functions such as integrated chassis control, driver assistance systems, or cooperative regenerative braking. Although the EMB system has the potential for numerous advantages and innovations in braking, it has yet to be successfully introduced in series production mainly due to safety and cost concerns.
Technical Paper
2014-09-28
Abdulwahab A. Alnaqi, Suman Shrestha, David C. Barton, Peter C. Brooks
Aluminium alloys have been used extensively in the automotive industry to reduce the weight of the vehicle and improve the fuel consumption which in turn leads to a reduction in vehicle emissions. The main aim of the current study is to replace the conventional cast iron rotor material with a lightweight alternative such as wrought aluminium alloy. The main challenge has been to meet both the cost and functional demands of the modern mass-produced automotive braking systems. A sensitivity analysis based on the Taguchi approach was carried out to investigate the effect of various parameters on the thermal performance of a typical candidate disc brake. Wrought aluminium disc brake rotors coated with alumina on the rubbing surfaces were chosen as the best option for replacing the conventional cast iron rotor at reasonable cost. Optimisation of the structure was subsequently carried out using a genetic algorithm on the selected coated aluminium disc brake rotor. This determines the optimum thickness of the coating and the composition of the substrate based on selected criteria.
Technical Paper
2014-09-28
Klaus Augsburg, Dzmitry Savitski, Lukas Heidrich, Valentin Ivanov
The presented study discusses design of brakes and brake control system for all-wheel drive electric vehicle equipped with individually controlled in-wheel motors (IWM). Initial part of the paper is dedicated to the analysis of different packaging of wheel brakes to be mounted together with IWM in the wheel hub. Special attention is given to the implementation of perimeter brake setup. Parameterization and design of specific perimeter brake configuration is introduced. The second part of the paper introduces advanced strategies for brake blending and ABS control. The proposed strategy of blending control realizes brake force distribution targeting the increase of regenerative braking with taking into account the limitations placed by the IWM operation. The ABS architecture is based on the direct slip controller. Its functionality will be illustrated with different case studies investigating the ABS braking with electric motors and hydraulic brake system. The particular attention is also given to the valuation of the brake comfort.
Technical Paper
2014-09-28
Zhizhong Wang, Liangyao Yu, Yufeng Wang, Kaihui Wu, Jian Song, Ning Pan, Liangxu Ma
The Distributed Electro-hydraulic Braking System (DEHB) is a wet type brake-by-wire system for passenger vehicles, and is especially suitable for electric vehicles and hybrid electric vehicles. The basic DEHB comprises four independent brake actuators connected to four hydraulic brakes. The word ‘distributed’ refers to the distributed arrangement of the brake actuators on the vehicle. Each brake actuator comprises an electric motor to provide brake power, a mechanism to translate rotational motion of the motor shaft into translational motion of a piston. The piston moves back and forth in a cylinder under the control of the motor to push the brake fluid into the brake. In this way, braking pressure can be controlled by the motor. Like other brake-by-wire systems, brake pedal simulator and pedal sensors are also used in DEHB. Although the concept of DEHB traces back to 1990s, only a few research papers can be found. This paper gives a review and outlook on the design concepts of DEHB from the following three aspects. 1.
Technical Paper
2014-09-28
Lu Xiong, Bing Yuan, Songyun Xu, Xueling Guang
At the very beginning part, a detailed analysis on current status of electro-hydraulic brake system is carried out. By analyzing 28 electro-hydraulic brake systems, the paper provides a brief summarization on structural components of typical electro-hydraulic brake systems from the perspective of main functional units. Then a more in-depth analysis is conducted on the key functional units, particularly on Active pressure-building unit and Pedal simulation unit. For instance, in terms of Active pressure-building unit, electro-hydraulic brake system schemes can be divided into two categories according to active power sources: one is pump + high-pressure accumulator, the other electric motor+ reducing mechanism. Then author employs MK C1, the latest electro-hydraulic brake system launched by Continental AG, to illustrate its structural components and working principle. In the second part, the idea of dual-motor electro-hydraulic brake system is proposed. As a new solution, dual-motor electro-hydraulic brake system can actively simulate pedal feeling and merge pedal power (from the driver ) into braking power at the same time, which is a distinctive innovation compared to most current electro-hydraulic brake systems.
Technical Paper
2014-09-28
Michael Herbert Putz, Christian Wunsch, Markus Schiffer, Jure Peternel
With linear actuated brakes the actuation force (or actuation torque) rises linearly from 0 to the full actuation force at full braking, causing a very variable motor current. The electro-mechanical brake (EMB) of Vienna Engineering (VE) uses a highly non-linear mechanism to create the high pressing force of the pad. The advantage is that the pad moves very fast when the pad pressing force is low and moves slower with increasing pressing force. This non-linear actuation means that the motor is always running at relatively constant load (although the pad pressing force changes highly), resulting in a motor that can be optimized for constant torque and constant rpm, reducing size and costs and increasing efficiency. The normal force in EMBs is often controlled by observing mechanical deformation to conclude to stress or force, commonly using strain gauges. It causes costs of the gauge itself and attaching them to e.g. the caliper and a sensitive amplifier. The full gauge equipment goes into the safety-related brake control system.
Technical Paper
2014-09-28
Liang Zhou, Chuqi Su
In this paper,a strategy for recovery of braking energy in HEV with EMB is proposed, which is less limited to the performance of the 42V vehicle power supply, compared with the conventional recycling strategy without EMB. In the traditional HEV with 42V vehicle power supply, recovery of braking energy is mainly recycled to the 42V battery, directly. As charging current is too large, or charging time is too long can damage the battery, 42V battery is difficult to recycle braking energy effectively ,especially in complex urban condition with vehicle braking frequently and rapidly. But in HEV with EMB,the recovery transfers to the motor of EMB directly, which is utilized dynamically in the process of vehicle braking. Excess electricity transfers to the energy storage unit if the generator is performing a voltage higher than the required voltage of EMB brake motor, otherwise, the energy storage unit to supplement electricity. The kinetic energy of the HEV turned into electrical energy to EMB timely,rather than being stored statically in this process.
Technical Paper
2014-09-28
Mandeep Singh Walia, Magnus Karlsson, Lars Hakansson, Gaurav Chopra
Mandeep Singh Walia An analysis method to study the potentials in recovering the brake energy from Volvo articulated haulers has been developed. The study is made to find out how and where possible hybrid solutions can be used. The method is based on the mapping of the peak brake power, brake energy and engine energy. The method was developed using adequate signals collected on haulers at three different customer sites. A conceptual study was also carried out concerning the brake energy to understand the actual amount of brake energy that may be stored in the Energy storage systems (ESS). The results indicate that the analysis method developed can map the brake energy generated and also provide an overview of the actual amount of brake energy that can be accumulated in the ESS, which can also guide in an effective selection of the ESS for a particular work site.
Technical Paper
2014-09-28
Stanislav I. Pliassounov
The article discusses the common shortcomings of contemporary standardized automotive brake tubing connectors (tube joints) against the modern requirements. During last decade modern production excellence mindset and lean manufacturing practice have developed additional requirements to the tube joints, with the focus on their assembly process. Correspondingly, at least 99.9% probability to assemble and seal each connector from the very first attempt at the designated assembly station is necessary to resolve the challenge. The article deliberates that 99.9% probability as the design target in pursuing connectors’ excellence. The article also discusses the pathway to the connectors’ design perfection via replacement of the existing cone-to-cone mating type between the sealing surfaces with a sphere-to-cone one. Operational windows’ comparison provides the evidences of feasibility and superiority of the latter. Further opportunities in development of quick (snapping) connectors with superior sealing robustness through following that pathway have been also discussed.
Technical Paper
2014-09-28
Kyung-Jung Lee, Jae-Min Kwon, Jae Seung Cheon, Hyun-Sik Ahn
X-by-wire technology replaces mechanical connections with electrical signals, and is indispensable for realizing an intelligent vehicle. The technology has many advantages including reduction of parts, increase in design degree-of-freedom, and safety increase. Especially, the Brake-by-Wire (BBW) system consists of electromechanical actuators and communication networks, instead of conventional hydraulic or electrohydraulic devices, has emerged as a new and promising vehicular braking control scheme. It offers enhanced safety and comfort, cuts off cost associated with manufacturing and maintenance, and eliminates environmental concerns caused by hydraulic systems. The BBW system has recently invoked a lot of interest for both industry and academia worldwide. The FlexRay is an automotive network communications protocol built to be a deterministic, fault-tolerant bus system. It was developed by the FlexRay Consortium as a conjunction with the leading automotive manufacturers. The FlexRay is a new time-triggered communication system for high-performance in-vehicle applications.
Technical Paper
2014-09-28
Nehal Goudar, Bhavesh Jain Lalwani
In this paper we study the utilization of aerodynamic forces to assist braking in high speed motor bikes. The motive of this study is to raise this effective braking force and thereby improve safety and reduce braking distance. This can be done through drag plates mounted on the sides on the fairing. Aerodynamic braking in bikes has not been studied in detail before and such a study will further open gates towards research on differential turning in bikes by varying the flap angles independently. The utilization of these drag plates is feasible only in bikes whose speeds are in excess of 120 kmph and preliminary study has indicated that the drag plates can provide braking force of up to 0.4G which is 40% percentage of the braking force by conventional braking. There are three major parts to this study. First stage is where various parameters such as material, size and shape are considered for the designing of the drag plates. Based on literature survey and packaging constraints around the bike various shapes of high drag coefficient plates are designed using software tools.
Technical Paper
2014-09-28
Prabhakar Nagalingam, J Suresh Gayakwad, N. Prabhakar, K. Muthumanickam, E. Nagaraj
The present investigation deals with the failure load prediction during the wrong procedure of unlocking the hand brake valve. The design of the hand brake valve top cover should have adequate strength such that the driver cannot move the lever without lifting the sleeve during brake off condition. The objective of this work is to design the top cover with higher stiffness such that it requires more load during wrong procedure of unlocking the valve. In this study, the nonlinear analysis is conducted (which includes three types of nonlinearities namely material, geometry and contact) in order to study the stiffness of the top cover during abuse condition. The design adequacy of the top cover is estimated by elasto plastic analysis. The maximum load carrying capacity of the top cover is determined from Force Vs Deformation plot which is good in agreement with the experimental results . Various design iterations are carried out to propose the appropriate design. The Computer simulation of the nonlinear analysis significantly reduces the time and cost required to design the top cover according to the customer requirement.
Technical Paper
2014-09-28
Ning Pan, Liangyao Yu, Zhizhong Wang, Liangxu Ma, Jian Song, Yongsheng Zhang, Wenruo Wei
With the purpose of individual wheel cylinder pressure regulation and independent of engine vacuum, Brake-by-wire (BBW) systems are suitable for electric vehicles and hybrid electric vehicles. BBW system has been developed in recent years. Electro-Hydraulic Brake (EHB) system is the first step towards BBW system. Various EHB systems have been proposed by researchers. A typical design includes a high pressure accumulator to supply pressure source and pulse width modulated (PWM) solenoid valves to regulate the brake pressure, such as the product of Bosch and Toyota. The electrically driven booster system uses motor to boost driver brake input, such as the system proposed by Mobis. Continental Teves proposed an EHB system with modified ESC hydraulic unit and electric vacuum pump. This paper proposes a new compact EHB system, arming at decreasing the size and cost without compromise of performance. There are there sections in this paper, the first section of which is system configuration and basic operation principles, the second section is the hydraulic pressure control algorithm to regulate the cylinder pressure, and the last section shows the simulation study to verify the performance of the new proposed EHB and its pressure control algorithm.
Technical Paper
2014-09-28
Ashesh Anil Shah, Umesh Abhyankar, Sanjay Patil
The customer satisfaction index is higher for disc brake systems because of the advantages like less reaction time, shorter stopping distance and improved pedal feel compared to drum brake system. In the current market scenario of global competition and as per customer requirements, front disc brake module is becoming necessary in almost every vehicle. In the existing vehicle it becomes challenging to replace front drum brake module with disc brake module because of the packaging constraint and vehicle has to undergo legislative verifications and certifications with respect to pedal effort, stopping distance and circuit failed conditions etc. This paper explains in details the packaging constraints to shift from drum brake to disc brake and innovative concept of disc brake which has met the all the legislation with cost and weight reduction without compromising performance with respect to conventional disc brake. In case of conventional brake disc system brake rotor (disc) is of hat type construction which is much complicated structure considering manufacturing and also time consuming due to higher manufacturing lead time.
Technical Paper
2014-09-28
David B. Antanaitis
It is obvious at this point even to the most casual observer of the automotive industry that efforts to reduce mass throughout the vehicle are at a fervor. The industry is facing its most significant increase in fuel economy standards in its history, and light-weighting the vehicle is a major enabler. Despite the performance and quality of the brake system being intensely related to its mass, it too has not been spared scrutiny. However, like many modern automotive subsystems, it is very complex and mass reduction opportunities that do not sacrifice performance or quality are not always obvious. There are some interesting and sometimes even profound relationships between mass and other vehicle attributes built into brake system design, and making these more visible can enable a better balancing of brake system with the rest of the vehicle design objectives. Examples include – what is the cost, in terms of brake system mass, of added engine power? Of tire and wheel size? What is the mass cost of brake pad volume and service life?
Technical Paper
2014-09-28
Liangxu Ma, Liangyao Yu, Xuhui Liu, Zhizhong Wang, Ning Pan
The paper is focused on the research of the automotive magneto-rheological brake system whose braking force comes from the shear stress of magneto-rheological fluid under the condition of magnetic field. The MRF brake is designed for a small-sized electric passenger car to replace a conventional hydraulic disc-type brake. The brake disk is immersed in the MRF whose yield stress changes as the applied magnetic field. The braking torque of this system can be linearly adjusted by the current in just a few milliseconds without the conventional vacuum booster. This system has a quick response and precise control performance with a low hysteresis. Besides, the system has adopted the original complicated structure to save space and cost. Nowadays, most of the related research of MRF is about the construction of the prototype and the realization of the brake force. However, due to a lack of optimal design and the understanding of MRF, the main research progress is only about the simulation and the braking effect of the prototype can hardly meet the requirement of the vehicle braking.
Technical Paper
2014-09-28
Mohamed Samy Barakat
The Braking System is the most crucial part of the racing vehicle. There is no doubt, that if only one minority failure in the braking system took place, this would be more than enough reason to cause the racing team disqualification from the competition. Time is the main and the most important criteria for any racing competition; on the other hand the formula student “FS UK SAE” competition care the most about developing the automotive engineering sense in the students by putting them under strict rules normally taken from the original version “formula 1” to encourage their creativity to reach the optimum performance under these strict rules. One of the most important rules is “No Braking by wire”, and the obvious consequences are more stopping distance and time. Braking distance is a critical facture in achieving racing success in a competitive domain. This report will cover using the bias bar, dynamic weight distribution “before and after braking” and carefully choosing the braking and suspension system components dimensions, in order to fulfill the main functions of “ABS and EBD” which are preventing the wheels from lock-up and preventing side skid of the vehicle during cornering in the different dynamic tests with full consideration of the maximum approachable deceleration of the vehicle without locking up without using any kind of electronic “actuators or control”.
Technical Paper
2014-09-28
Guoling Wang, Xuexun Guo, Quan Zhou
New regulation was enacted in China for the aim of transportation safety, which said all heavy trucks should install air disc brake (ADB) on the front axle. From this compelling measure, we can see air disc brake must be better in performance. In fact ,compared with the conventional brake, the air disk brake has great superiorities in performance,installation , dependability and maintenance. As one of the most important stress parts of ADB, the actuating arm magnifies the force received from the brake cylinder and pushes the bridge forward through a rolling traverse. The tappet fastened on the bridge extends perpendicularly to the plane of the brake disc and then brake torque appears on wheels. The actuating arm is a lever substantially. The lever rate is key point influencing the quantity of braking torque. Meanwhile , for heavy truck, great brake torque is needed, it can be as large as 220kN•m. So the actuating arm should be strong enough to endure enormous pressure. Therefore, it’s necessary to give a specification about the calculation of the lever rate and the strength analysis of the actuating arm.
Technical Paper
2014-09-28
Shiwalik Ghosh, Baskar Anthony samy, Rajvirendra Singh Balwada, Ravi kaushik
The behavior of an automobile undergoing braking is critical in terms of both performance and passenger safety. The brakes are the single-most important safety component on an automobile, and are charged with the vital task of stopping the moving vehicle. The basic goals of braking systems are to decelerate a vehicle during stopping, to maintain vehicle speed during downhill operation, and to hold a vehicle stationary on a grade. Like many other aspects of automobile design, brake hardware is conventionally designed as a compromise between the different performance requirements. Furthermore, a factor of safety is designed into the components to assume best performance during ideal testing conditions, this could lead to a limiting performance in unfavorable conditions. New developments in integrated braking devices will give brake designers the freedom to control brake force without compromise, in order to ensure optimal braking and vehicle stability under all conditions. This thesis will investigate some of the possibilities in this area.
Technical Paper
2014-09-28
Shiwalik Ghosh, Baskar Anthonysamy, Ravi kaushik
Prevailing cut-throat competition in Indian Two wheeler segment confronts to enhance performance of traditional braking system with reduction in cost and weight as substantial consideration. The need of the hour requires subjecting the braking system to variable parameters to achieve progress in minimizing Stopping distance and increasing Mean Fully Developed Deceleration (MFDD). The purpose of this study is to augment the braking performance of two wheeler segment by comparing various combinations of twin leading drum brake layouts by method of Virtual Simulation. The conventional drum brake system utilizes one cam, one pivot, one leading shoe member and one trailing shoe member. In the event of braking, leading shoe causes the generation of drag force. The other shoe is "trailing", moving against the direction of rotation, is thrown away from the friction surface of the drum and is far less effective. The present study highlights the incorporation and enhancement of braking characteristics of bigger brake drum system into smaller brake drum system through the adoption of Twin Leading Shoe (TLS) concept with the added advantage of reduction in cost.
Technical Paper
2014-09-16
Viacheslav Pshikhopov, Mikhail Medvedev, Victor Krukhmalev, Roman Fedorenko, Boris Gurenko
The paper describes methods for control of docking of two moving stratospheric airships. One of them (cruiser) implements cruising flight at the defined altitude with defined velocity. The other one (feeder) fulfills the mission of chasing the cruiser with following docking operations. Mathematical model of exact airships are used in the work. Instances of structural and algorithmic implementation based on position-trajectory controller. Simulation of docking control were accomplished with proposed methods.
Technical Paper
2014-09-16
Rudolf Neydorf, Sergey Novikov, Nikita Kudinov
The airships constructors are exploring applications of the systems of many ballonets for roll airship control and attack angle airship control. However, this requires an effective automatic control system each of separately ballonet and for the entire system coordinated automatic control. This is especially necessary for unmanned airships and it makes it relevant the mathematical description, design and research of the systems and control laws for the airships having system of many ballonets. The automatic regulation of the system of many ballonets is a very difficult problem. This is because the some state variables of the separate ballonets are the technically not measurable variables. Mathematical model describes the change of the overpressure in the hull of the airship, and evaluates the process of this change. However, it does not allow calculating the mass of air in each ballonet. It is needs a system of differential equations for each of the ballonets. This is possible either by direct measurement of the volume of ballonets or by their dynamic identification as status variables.
Technical Paper
2014-09-16
Jay Wilhelm, Joseph Close, Wade Huebsch
A Hybrid Projectile (HP) is an aerial vehicle that is ballistically launched, and then transforms into an Unmanned Aerial Vehicle (UAV). It was desirable for a surveillance equipped HP to change its trajectory, and ultimately the point of impact, by departing from its ballistic trajectory after being launched. The exact control surface sizes, location, and actuation along with the control strategies were needed. A method was investigated to utilize deflectable control surfaces in conjunction with a guidance system to maneuver to HP to a desired point of impact while ensuring that the projectile remains statically and dynamically stable. Dual feedback control methods were devised to control heading and pitch using deflectable vertical and horizontal tail surfaces. These control methods were tested and tuned using the Six Degree of Freedom (6DoF) system in Simulink. A cruciform tail section, analyzed in previous work for a 40 mm HP, was utilized so that the HP was statically and dynamically stable.
Technical Paper
2014-09-16
Mario Luca Fravolini, Matthew Rhudy, Srikanth Gururajan, Silvia Cascianelli, Marcello Napolitano
A measurement device that is extremely important for Unmanned Aerial Vehicle (UAV) guidance and control purposes is the airspeed sensor. As the parameters of feedback control laws are conventionally scheduled as a function of airspeed, an incorrect reading (e.g. due to a sensor fault) of the Pitot tube could induce an incorrect feedback control action, potentially leading to the loss of control of the UAV. In this paper, building on prior research, the authors compare two models for Pitot tube free airspeed estimation. The analysis was carried out based on multiple flight records is acquired from the West Virginia University YF-22 scale model in order to assess their performance. The objective of this study is to establish the accuracy and reliability of the two airspeed estimation techniques for eventual use as the basis for real-time fault detection of anomalies occurring on the Pitot tube sensor. The first technique is based on an Extended Kalman Filter (EKF) that utilizes the nonlinear kinematic relations between GPS, Inertial Measurement Unit and Air Data System signals.
Technical Paper
2014-09-16
Rudolf Neydorf, Youriy Sigida, Nikita Kudinov, Elena Portnova
During the development and study of airships controlled movements are applied computer simulation methods, since the size of these air vessels do not allow to apply physical modeling. Computer model is needed to simulate not only the shape and movement of the airship, but also the conditions (parameters) of the flight environment. It is atmospheric conditions typical for the air vessel route [R. Neydorf, V. Krukhmalev, N. Kudinov, V. Pshikhopov «Methods of Statistical Processing of Meteorological Data for the Tasks of Trajectory Planning of MAAT Feeders», SAE Technical Paper 2013-01-2266, 2013]. Atmospheric environment settings depend on the geographical position, the planned heights of flight of the aircraft, calendar and time periods (time of year, month, and time of day). In addition, the atmospheric parameters depend on the spontaneously emerging phenomena of weather conditions. As a result these variables have both a regular component and a random component. The first determined by both geographical conditions, and calendrical and time conditions.
Technical Paper
2014-09-16
Yvan Wilfried Tondji Chendjou, Ruxandra Botez
Measurements of the inertial properties are needed during the design of aircrafts. Furthermore, the knowledge of these measurements is one of the most problems to be solved while studying aircraft rotational motion or even designing aircraft flight control systems. This is the reason why accurate methods for computing aircraft inertial properties have received sustained interest over the years. This paper firstly presents a structural analysis of a drone - the UAS-S4 ETHECATL. Mass, center of gravity position and mass moment of inertia are numerically determined through Raymer and DATCOM statistical-empirical methods, coupled with mechanical calculations. Then, experimental tests are performed using the pendulum method, in order to validate the numerical predictions. When experimentally determining the mass moment of inertia, the bifilar torsion pendulum is used for the moment vertical axis and the simple pendulum for the moment longitudinal and transversal axes determination. A nonlinear dynamic model is developed for rotational motions about the center of gravity of the system under tests.
Technical Paper
2014-09-16
Srikanth Gururajan, Mario Luca Fravolini, Matthew Rhudy, Antonio Moschitta, Marcello Napolitano
Recent catastrophic air crashes have shown that physical redundancy is not a foolproof option for failures on Air Data Systems (ADS) on an aircraft providing airspeed measurements. Since all the redundant sensors are subjected to the same environmental conditions in flight, any failure on one of the sensors is likely to occur on the other sensors under certain conditions such as extreme weather; this class of failure is known in the literature as “common mode” failure. In this paper, different approaches to the problem of detection, identification and accommodation of failures on the Air Data System (ADS) of an aircraft are evaluated. This task can be divided into component tasks of equal criticality as Sensor Failure Detection and Identification (SFDI) and Sensor Failure Accommodation (SFA). Data from flight test experiments conducted using the WVU YF-22 unmanned research aircraft are used. This research platform was designed, manufactured, instrumented, and flight tested by researchers at the Flight Control Systems Laboratory (FCSL) at West Virginia University (WVU).
Technical Paper
2014-09-16
Massimo Conte, Michele Trancossi
This paper presents the definition of a novel system for autonomous landing and docking, which has been conceived and developed inside the MAAT project, to allow an effective control during autonomous docking of cruiser and feeder in movement. In particular, this paper is a fundamental technological spin off the MAAT project. It is a new instrumental system for governing relative positioning between a movable target and air vehicles, such as helicopters, airships and multi-copters. In particular, a short time to market application relates to helicopter equipment (both manned and unmanned) to ensure autonomous landing capability even in case of reduced visibility. The proposed solution is based on infrared emitters allowing controlling both position and jaws angle. It is in advanced testing phase have concluded a preliminary testing phase using a quadcopter which has landed on a small platform mounted on an unmanned with capability of landing also in movement. The proposed solution is an effective alternative to more sophisticated vision based systems, which ensures higher affordability, higher simplicity and reduced costs.
Book
2014-09-04
William C. Messner
Over the years, the DARPA Challenges in the United States have galvanized interest in autonomous cars, making them a real possibility in the mind of the public, but autonomous and unmanned vehicles have been increasingly employed in many roles on land, in the water, and in the air. Military applications have received a great deal of attention, with weaponized unmanned aircraft (drones) being the most prominent. However, unmanned vehicles with varying degrees of autonomy already have many civilian applications. Some of these are quite familiar (such as the Roomba autonomous vacuum cleaner), while others remain largely out of the public eye (such as autonomous farm equipment). Additional applications and more capable vehicles are rapidly coming to the markets in the years ahead. This book examines a number of economically important areas in which unmanned and autonomous vehicles, also understood here as autonomous technologies, are already used or soon will be. Co-published by SAE International and AUVSI, Autonomous Technologies: Applications That Matter will assist the reader in identifying profitable opportunities and avoiding costly misconceptions with respect to civilian applications of autonomous vehicle technologies as it brings together chapters on how air, water, and ground vehicles are becoming ever more used and appreciated.
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