The vertical flight industry is on its way to a transformative era, with autonomous technologies set to alter aerial vehicle operations. While it seems certain that fully autonomous helicopters will eventually be deployed for a variety of missions, some high-stakes situations—like medical evacuations (MEDEVAC)—will for the foreseeable future demand human participation in the form of Emergency Medical Care-giving Crew. This study describes the testbed built to run and investigate hypothetical future situations in which a helicopter is autonomously piloted while a human medic with no aviation training, subjected to aviation and medical emergencies, manages patient care onboard. A total of 22 participants, with emergency medical technician certification, nursing or a medical board certification, were invited to run and evaluate the use of AI pilot (AP) in different scenarios of medical evacuation under the following emergencies: medical, empty fuel tank, pressure sensor miscalibration

Doda, Sanya, Feigh, Karen, Agbeyibor, Richard, Cortes, Carmen, Kolb, Jack, Magalhaes, Jose

Optimizing Comprehension and Performance in Technical Documentation: Does Adding Multimedia to Written Instructions Help to Safely and Accurately Perform Maintenance Tasks?

F-0081-2025-0144

5/20/2025

As part of a human factors research project aimed at optimizing technical documentation used in helicopter maintenance with multimedia elements, we compared different instruction formats to observe their effects on the performance of an assembly task. This task offers us the opportunity to test procedures that call for similar actions as a maintenance task (e.g., localization, action sequencing, assembly). Static (i.e., image and image with text) and dynamic instruction formats (i.e., video, video with text and video with audio) were compared to determine if dynamic formats allowed a better motor performance of the task for assembly reaction time (time needed to complete the assembly) and accuracy. We were also interested in how the use of the text instructions interacted with both visual dynamic and static instructions. Reaction times were recorded and measured with eye tracking data. Subjective data was collected in questionnaires during and after the experiment. Results showed

Faye, Myriam, Jahchan, Nataly, Condamines, Anne, Amadieu, Franck

Exploring capabilities of hydraulic actuators to achieve vehicle ride targets in frequency range beyond their operational bandwidth

2024-26-00601/16/2024

Active suspension systems employ sophisticated control algorithms to deliver superior comfort in vehicles. However, the capabilities of these algorithms are limited by the physical constraints of actuators. Many vehicles use hydraulic actuators in their active suspension system, which use fluid movement to control suspension motion. These systems inherently have slower response times due to the nature of fluid flow and the time required to build up or release pressure within the hydraulic system. Typically, hydraulic systems operate in a low bandwidth of 0-5 Hz. This limits their capability to only meeting vehicle’s primary ride targets which typically lie below 5 Hz. Although, they can be tuned to operate at slightly higher frequency range (up to 10 Hz), they perform poorly in attenuating the secondary ride vibration, i.e., 5 – 25 Hz. This paper focuses on identifying and developing control strategies that can allow us to affect the vehicle ride well beyond the actuator bandwidth. The

Agrawal, Ayush, Negi, Ayush, Joshi, Divyanshu

Model based Charge control for 3-cylinder TGDI Miller engine containing variable geometry turbocharger

2024-26-00431/16/2024

With the increase in the number of automobiles, there is a very strong emphasis on reducing the CO2 pollution which led to evolution of miller cycle engines. However, the inherent characteristic of Miller engine is the lower volumetric efficiency when compared to otto engines because of which small turbo chargers with variable geometry turbines are used to induct air into the engine. With miller engine and VGT turbo charger combination arises the challenges of charge controllability because of lower inertia and reduced vane control area. With conventional turbo charger control methods, the response time is slow thereby leading to turbo lag or sever over boosting, this is overcome by accurate engine modelling and using the same as input for charger control. In this study, model-based calibration approach was performed on a 1.2Litre 3 cylinder Miller GDI engine to model the charge exchange of the engine and use the same for determination required turbine vane positions to achieve the

Veeramani, Vivekanand, Karthi, Ramanathan, Shanmugam Ramakrishnan, Muthu

Digital Manufacturing Execution System for Special Processes

2022-26-11685/26/2022

Processes like Chrome Conversion Coating, Painting, Temper ETCH are categorized as Special Process in Aerospace. They have many variables in the process which need to be monitored, recorded and inter relationship studied using ML & AI. Study of Process Parameters using IIoT, their impact on Quality and the impact on life cycle (Industry 4.0) due to the process parameters maintained at that time of manufacture needs specialized, customized software for each and every process. The said software needs to have checks and alerts for maintenance of Process parameters. It should, on a daily basis do a few lab measurements to cross check whether the automated measuring accuracy is correct or not. Regular empirical calculations for the concentration of baths should be done and an 'alarm' needs to be raised if any mismatch with actual measurement is found. This way regular checking of measuring instruments should be carried out. This also ensures that the issue is found out before it translates

Damodaran, Ramamurthy

Predicting Driver Emergency Response Behaviour through Time-to-Impact

2022-01-09713/29/2022

Conventional forensic analyses of collision avoidance behaviours involve assigning a perception and response time (PRT) interval to a driver that precedes the onset of evasive action. However, this approach relies on the investigator identifying a ‘time zero’ for when to begin the PRT interval, which should align with the first moment of hazard detection. Depending on the incident circumstances, this moment may not be readily apparent or appropriate. Recent research has shown potential for a more universally applicable method that is based on the relationship between response onset and the projected time-to-impact (TTI). Accordingly, the aim of this research is to further investigate this relationship with diverse hazard scenarios. Twenty-one subjects viewed driver-perspective recordings of a simulated vehicle travelling down a major roadway past several two-way stop-controlled minor roads. At various intersections, intruding vehicles entered from either the left or right. These

Erazo, Fabian, Campbell, Adam

Three-axle Bus Handling Dynamics Evaluation Index

2022-01-03413/29/2022

This paper evaluates the handling characteristics of three-axle bus by using the unique comprehensive vehicle handling evaluation index. With the theory of total variance, the generalized side-slip angle unified transfer function is introduced to derivate the evaluation indexes of reaction time, transition time, damping ratio and total variance considering the suspension roll steer and camber thrust. The three-axle bus suspension roll steer and camber thrust produces extra lateral force. The three-axle vehicle response degree following the step steer input is analyzed with the effect of suspension roll on three-axle bus by using the total variance approach. The vehicle designers could use this approach to get optimization design parameters of bus suspension. The unique total variance evaluation index considering the suspension roll steer is useful and could serve as an important tool for evaluating the effect of suspension roll on three-axle bus handling dynamics.

Ding, Jinquan

Prediction of Lane Change on the Expressway Based on Logistic Regression

2021-01-703212/15/2021

In autonomous driving system, lane change decision-making plays an important role as the front-end of lateral control. However, the current prediction methods of lane change are typically performed by using basic variables as the features of model without deep processing, which reduces the accuracy of the prediction. Therefore, we propose a binary logistic regression method to solve the lane change decision problem under expressway conditions, which treat quantified willingness and risk as the inputs. Firstly, we design Lane Changing Willingness function and Lane Changing Risk function with the minimum safety spacing theory and traffic environment factors. Secondly, a binary logistic regression method for predicting lane change behavior is proposed. Thirdly, we develop the driving simulation platform with low latency data collecting tools and design the experiments. After training the model with the experiment data, the proposed method predicts the lane change decision with 94.02

Sun, Weiqi, Bai, Jie, Huang, Libo, Chang, Liang, Dong, Lianfei, Luo, Zhengang

SAE TOMORROW TODAY: Empowering Superheroes: Emergency eVTOL Aircraft from Start-Up Jump Aero

1317311/28/2021

In emergency situations, every second counts - but long distances to rural areas and congested city traffic often increase the time it takes to transport a patient to a hospital. Jump Aero is mobilizing eVTOL aircraft as a solution to cut emergency response time in half and save thousands of lives. Co-founders Carl Dietrich, President/Chief Designer, and Katerina Barilov, Head of Business Development, discuss their passion for the Jump Aero mission. Hear more about how electric aircraft can reduce the time it takes to get a responder on the scene, why their EMTs are required to learn how to fly an airplane, and how their commitment to engage with EMS communities builds partnerships and trust. Stay up to date on the latest news from Jump Aero: https://www.jumpaero.com/

Hineman, Marcie

Development of Thermal detection device for Automotive vehicles to monitor human body heat

2021-26-02329/22/2021

According to research study Epidemics such as SARS, COVID-19 spread have caused huge negative impacts on population health and the economy around the globe. The outbreak placed a huge burden on international health systems that were already straining to address AIDS, tuberculosis, malaria, and a host of other conditions. Research has proven that if infected person is not found easily then spread of infection in society will takes the shape of large-scale community transmission. Most of the infection spared cause due to infections may go unnoticed from the infected person. One part of the access checker scans a person’s body temperature by measuring infrared radiation emitted by their skin. Fever screening by infrared thermal imaging has become more widespread following the SARS infection, and particularly during the pandemic H1N1 and COVID-19 outbreak. skin temperature measured without contact by monitoring the emitted infrared radiation. Infrared thermal camera that monitor radiations

Pajgade, Sachin Madhukarrao, Bhargava, Aashish

Co-Simulation of BLDC Motor Control and Clutch actuation system with Ball Ramp Mechanism

2021-01-12369/21/2021

Electro-mechanical actuators are widely used in different forms in the automotive industry these days and are very effective in translating rotary motion of the motor to a linear motion with precision as per the requirement. With onset of electric drivelines and other complex driveline configurations, we see an increase in actuator applications. In this study, we developed high fidelity analytical model for a ball ramp clutch actuation system as per the proposed mechanical design and the software controls. The controls architecture is built in SIMULINK environment to drive the plant model of the BLDC motor. Whereas, the entire mechanical system which includes the gear train, ball ramp mechanism, clutch pack stiffness, etc. is modelled in ADAMS tool. The Ball Ramp consists of metal balls positioned in between opposing paired arc-shaped ramp grooves and guided by a cage to keep them equally separated in the same plane. While ADAMS model deals with high-fidelity contact dynamics using non

Rajendran, Raveen K., Roy, Nantu, Mehta, Yogesh

Prediction of Biodiesel Production from Sardine Fish Oil Methyl Ester Using Microwave Assisted Transesterification Method Using Response Surface Methodology

2021-01-12029/21/2021

This study presents a demonstration of generating biodiesel from fish oil utilising microwave with a significant reduction in the amount of catalyst needed during the reaction and the time of reaction. Various factors such as microwave power, catalyst concentration, reaction duration, and molar ratio were tested experimentally. The response surface approach was used to improve the reaction parameters. As reaction parameters, four levels were chosen: molar ratio, catalyst concentration, and reaction time. According to the RSM model results, molar ratio has a crucial role in the transesterification of fish oil to bio diesel. Confirmatory tests were carried out to validate the acquired data, and they proved to be worthwhile.

Sathyamurthy, Ravishankar, CHANDRA SEKHAR, S., Venkatesan PhD, M

Drivers’ Responses to Lead Vehicles: Thresholds for Triggering an Emergency Response, Age Differences, Crash Risks, and Influence of Secondary Task Engagement

2021-01-08984/6/2021

Analyses of driver response time studies and fatal crash statistics were examined to determine: 1. whether all rear-end crash types can be analyzed as one crash type, 2. average braking thresholds for drivers, and 3. the influence cell phone usage has on drivers’ response times when responding to a lead vehicle. The goal of this research is to recommend protocols for investigating LV crashes that is supported by the literature. Two distinct lead vehicle [LV] response time events emerged: LV platoon (two vehicles traveling together in close proximity) and LV looming (a vehicle approaching a stopped or much slower LV). In normal driving, platoon LV events were very common but resulted in very few crashes per exposure. Young drivers were over-represented when they did occur. Onset of the hazardous event was when the LV decelerated, and drivers began braking roughly 3 to 5 seconds before impact. These results were consistent with the braking thresholds by naturalistic drivers in congested

Muttart, Jeffrey, Dinakar, Swaroop, Edewaard, Darlene

Development of On-Board NH ₃ and N ₂ O Analyzer Utilizing Mid-Infrared Laser Absorption Spectroscopy

2021-01-06104/6/2021

The authors present a portable NH3 and N2O analyzer utilizing mid-infrared laser absorption spectroscopy for on-board emission measurements. The developed analyzer employs a newly developed absorption spectroscopy named “infrared laser absorption modulation”, hereinafter referred to as IRLAM, for the signal acquisition and concentration determination. Because of IRLAM’s simple and robust signal processing scheme, a highly sensitive, selective and robust measurement system can be realized within a compact size. The following performance metrics of the new analyzer are presented: linearity, detection limit, response time and zero/span drift. Notably, the detection limit (defined as 2σ of the zero signal) of ≤ 0.1 ppm is achieved in both NH3 and N2O measurements. The influence of vibration, and changes in environment conditions such as ambient temperature and atmospheric pressure, are also tested. The effect of random vibrations had little observable impact on the measurement noise level

Onishi, Yusuke, Hamauchi, Shota, Shibuya, Kyoji, McWilliams-Ward, Keegan, Akita, Masanobu, Tsurumi, Kazuya

A Research on Modeling and Pressure Control of Integrated Electro-Hydraulic Brake System

2021-01-01304/6/2021

A fourth-order mathematical model for I-EHB (integrated electro-hydraulic brake) system was derived from its mechanical and hydraulic subsystems. The model was linearized at equilibrium state and then was verified by AMESIM software. The friction model of the system was analyzed based on static friction and viscous friction. A bench test was designed to identify the parameters of friction model. As the I-EHB system worked at different braking conditions, a PID-based switching controller was designed to track the target servo cylinder pressure. Both simulations and experiments results showed that, the response time of pressure was less than 120ms, and there was no overshoot, which helped handling different braking conditions and improving the braking safety and comfort.

Wang, Bing, Wang, Minghui, Jiang, Yongfeng, Shangguan, Wen-Bin

Large-Area Flexible Organic Photodiodes

TBMG-383151/1/2021

The performance of flexible large-area organic photodiodes has advanced to the point that they can now offer advantages over conventional silicon photodiode technology, particularly for applications such as biomedical imaging and biometric monitoring that require detecting low levels of light across large areas.

Plant-Based Thermotherapy Patch

TBMG-3815212/1/2020

A biodegradable, transparent, flexible and fast-acting thermo-therapy patch from plant leaves is compatible with flexible electronic applications. Plant material was used to reduce the amount of electronic waste.

Designing High Reliability into Life-Saving Cardiac Care Instruments

TBMG-3816212/1/2020

One type of electronic device where high reliability is the most important design objective is medical instrumentation. Instruments such as defibrillators, which provide life-saving electrical stimulation of the heart, and portable ultrasound machines that can provide critical diagnoses such as mitral valve defects, are mission critical and must have a robust design to ensure that they maintain the necessary uptime for patient care. The markets for these instruments are both large, approximately $10 million for defibrillators and $7 million for ultrasound instruments and growing at a minimum of a compound annual growth rate of over five percent.1, 2

Driver Drowsiness and Fatigue in the Safe Operation of Vehicles - Definition of Terms and Concepts

J3198_202010 (Current)

10/26/2020

This SAE Information Report provides definitions and discussions of key terms concerning driver drowsiness and fatigue, and basic information on measuring drowsiness and fatigue. It also includes information and concepts for driver drowsiness as they relate to the safe operation of a vehicle. The key driver drowsiness and fatigue causal factors include the following: (1) sleep quality and quantity, (2) time of day, (3) time awake, (4) time on task (modulated by characteristics of the driving task), (5) task-related fatigue (variations of arousal levels related to task underload and overload), and (6) combinations of these factors. Medical conditions, medication, alcohol, or drugs exacerbate drowsiness; however, the discussion in this report is limited to fatigue concepts. This report has two primary outputs: (1) definitions and discussions of key terms concerning driver drowsiness and fatigue, and (2) basic information on measuring drowsiness and fatigue and its effects on the safe

Driver Metrics, Performance, Behaviors and States Committee

Influence of Optical and Gravito-Inertial Cues to Height Perception During Supervisory Control

F-0076-2020-16417

10/5/2020

Future vertical lift (FVL) missions will be characterized by increased agility, degraded visual environments (DVE) and optionally piloted vehicles (OPVs). Increased agility will induce more frequent variations of linear and angular accelerations, while DVE will reduce the structure and quality of the out-the-window (OTW) scene (i.e. optical flow). As helicopters become faster and more agile, pilots are expected to navigate at low altitudes while traveling at high speeds. In nap of the earth (NOE) flights, the perception of self-position and orientation provided by visual, vestibular, and proprioceptive cues can vary from moment to moment due to visibility conditions and body alignment as a response to gravitoinertial forces and internally/externally induced perturbations. As a result, erroneous perceptions of the self and the environment can arise, leading ultimately to spatial disorientation (SD). In OPV conditions, the use of different autopilot modes implies a modification of pilot

Godfroy-Cooper, Dr., Denquin, Francois, Bachelder, Dr., Miller, Joel, Jean, Dr.

Possible Significant Response Speedup from Detuning a Resonator Bolometer

TBMG-3778810/1/2020

Kinetic inductance bolometers and calorimeters, each consisting of a kinetic inductance device (KID) suspended on a membrane and embedded in a resonant circuit, are being developed for applications such as planetary science, climate science, and X-ray spectroscopy. Arrays of these resonator-bolometers, each with a unique resonant frequency, are coupled to a single feedline, allowing many bolometers or calorimeters to be multiplexed using microwave readout. These devices potentially offer a combination of high sensitivity, large arrays, and broadband response not available from competing technologies.

Development of Design and Engineering Recommendations for In-Vehicle Alphanumeric Messages

J2831_202007 (Current)

7/29/2020

This Information Report provides recommendations for alphanumeric messages that are supplied to the vehicle by external (e.g., RDS, satellite radio) or internal (e.g., infotainment system) sources while the vehicle is in-motion. Information/design recommendations contained in this report apply to OEM (embedded) and aftermarket systems. Ergonomic issues with regard to display characteristics (e.g., viewing angle, brightness, contrast, font design, etc.) should review ISO 15008.

Driver Vehicle Interface (DVI) Committee

Q&A

20TOFHP06_136/1/2020

Comfort Motion Global (CMG) engineers have developed and refined a “proactive” Motion Seating software technology throughout the past 15 years that improves blood flow and reduces occupant fatigue through automated, micro-adjustments (1° or less) of the driver and passenger seats. Studies conducted with researchers at Ball State University for passenger vehicles showed an increase in driver alertness. Reaction times improved by 200 milliseconds between the static seat and the motion seat, which translates to about 17 to 20 feet of stopping distance, according to Dr. Paul Phipps, an Indianapolis-based chiropractor who developed the customizable algorithm. The proprietary technology recently launched on a range of Mercedes-Benz vehicles, and now CMG has its sights set on the commercial trucking industry - a logical next step since truck drivers are on the road for extended periods of time. The company is working with several commercial-vehicle suppliers and fleet owners to make the

Gehm, Ryan

A Performance Measurement and Analysis Method for Infotainment System

2020-01-13474/14/2020

The software must be verified and optimized from time to time to ensure system performance quality from the development process. Because the later you discover performance issues, the greater the cost of performance improvements, along with the extent to which they are fixed in the source code. In particular, performance problems due to poor system design should be identified and corrected as soon as possible. Also, as development progresses, source code added for new features and modified by bugs can potentially increase system resource usage or worsen responsiveness. Therefore, the development process needs to periodically measure, analyze, and improve system performance. This paper introduces the system-wide performance analyzer and explains how to use it to measure and analyze the performance of the infotainment system for performance management and improvement. Also describe the application cases that use it, finally, explain future development directions to cover the area of the

Lee, Peace

Leverage wireless technologies in timber harvesting to enhance operational productivity and business profitability

2020-01-13784/14/2020

Growing needs of forestry products; primarily wood followed by pulp and paper industry have mechanized the process of harvesting timber in most part of world. Such job sites have several machines and vehicles working together to harvest and transport the logs. Timber logging is very similar to crop harvesting with longer harvesting cycle and hence it is critical that every part of it is effectively utilized; timely harvest and transport to factories play an important role. Traditionally, these areas have had little cellular connectivity, restricting communication between operators, machines, land owners and factories. With better connectivity, it will be easier to monitor and operate job sites for example if skidder would know how many trees are felled, how many logs and bunches are created and where they are kept; it would reduce time and fuel spent in searching for logs. Also, with better communication between machines, skidder would know when to pick up logs and avoid longer wait

Pandit, Ishani, Iyer, Suchitra

Investigation on Safety Improvements by Lighting for Pedestrians and Cyclists

2020-01-06334/14/2020

The paper will describe actual investigations on safety improvements by new lighting functions. Especially the new chance of projections on the road surface either by simple reflector technology or by modern signature and pattern projection will be investigated. Several different prototype technology will be checked by a set of new parameters, e.g. reaction time to signals, clear understanding, minimum and optimum visual contrasts etc.

Hamm, Michael, Hinterwaelder, Christian

Best Practices for Medical Device Design: Five Strategies for Success

TBMG-364144/1/2020

The medical industry is behind the times when it comes to user-centered design and user experience. Healthcare professionals are demanding a consumer product level experience. “Make it like my iPhone” is a phrase we have all heard. UX (user experience) positions and UX boot camps are starting to emerge in large medical companies to solve this problem but plugging in a prescribed process won’t cut it. When it comes to medical device design, the stakes are higher, the environments more extreme, and the technology more complex, not to mention the reign of regulatory.

The Effect of An Acoustic Startling Warning On Take-Over Reaction Time And Trunk Kinematics for Drivers in Autonomous Driving Scenarios

2019-22-00223/31/2020

The Acoustic Startling Pre-stimulus (ASPS, i.e. a loud sound preceding a physical perturbation) was previously found to accelerate action execution in simple flexion exercises. Therefore in this study we examined if ASPS can accelerate take-over reaction times in restrained teen and adult drivers who were asked to reach for the steering wheel while experiencing sled lateral perturbations simulating a vehicle swerve. Results showed that adult drivers lift their hands toward the steering wheel faster with the ASPS versus without (161 ± 23 ms vs 216 ± 27 ms, p<0.003). However this effect was not found in teens or in trials where the drivers were engaged in a secondary task. Adults also showed reduced lateral trunk displacement out of the seat belt with the ASPS. The ASPS could represent a novel warning that reduces take over time and out-of-position movements in critical autonomous driving scenarios.

Graci, Valentina, Griffith, Madeline, Maheshwari, Jalaj, Akkem, Rahul, Austin, Meta, Seacrist, Thomas, Arbogast, Kristy B.

The 6 Most Important Parts of a Temperature Monitoring System

TBMG-3546211/1/2019

In the past few years, it has become increasingly common for hospitals, clinics, healthcare and life science organizations, and other businesses to use an electronic temperature monitoring system to safeguard their products and satisfy regulatory demands. You may know that you need a monitoring system, possibly with alarming capabilities, but aren't sure how to select the best one to meet your needs. To complicate matters, there are literally dozens of different types of temperature monitoring systems with different features and a wide range of prices.

Fiber-Based Artificial Muscles

TBMG-351329/1/2019

While different approaches have been used to create artificial muscles — including hydraulic systems, servomotors, shape-memory metals, and polymers that respond to stimuli — they all have limitations such as high weight or slow response times. A fiber-based system was developed that is extremely lightweight and can respond very quickly.

Organic Semiconductor Thin-Film Sensors Detect Disease Markers in Breath

TBMG-348958/1/2019

Organic semiconductors (OSCs) have emerged as a new class of electronic materials promising a wide range of applications including organic field-effect transistors (OFET), solar cells, thermoelectrics, electronic skins, and chemical and mechanical sensors by virtue of their chemical versatility, solution processability, and mechanical flexibility.

German University Studying Assisted-Driving ‘Handoff’

19AVEP07_087/1/2019

Germany's Kempten University Adrive Living Lab will feature latest aVDS driving simulator to research ADAS stress levels. Researchers at Germany's Kempten University of Applied Sciences plan to embark this year on autonomous vehicle (AV) and advanced driver-assist system (ADAS) programs that will include investigation of the safest ways to achieve handover of a vehicle when control is returned to a human driver. To do so, it is installing an AB Dynamics advanced Vehicle Driving Simulator (aVDS) that will help measure driver stress levels if the vehicle is not capable of performing a particular maneuver. The aVDS has been designed to provide high level R&D capabilities specifically for autonomous systems. The university has established its Adrive Living Lab with the third-generation simulator helping to facilitate the study of the driver's interaction with autonomous systems and their effect on drivers' perceived safety and comfort. The program has identified these two areas as the most

Birch, Stuart

High Tech Comes to Fitness Monitoring

TBMG-345826/1/2019

Early wearable fitness monitoring devices were designed to perform a set of valuable but straightforward activities: tallying the number of steps we take daily, recording the number of hours we sleep, and monitoring our heart rate.

When You Need a Machine for Breathing, You’d Better Have Accurate Sensors

TBMG-345916/1/2019

Medical ventilation technology has come far since the original iron lung was first used more than 90 years ago. Using negative pressure to ventilate, the patient was inserted into an airtight chamber looking like a prop from a Sci-Fi movie. The iron lung mimicked the physiological act of breathing. Pumps controlling airflow periodically increased and decreased air pressure within the chamber and thus indirectly in the patient’s chest. Lungs were inflated by applying negative pressure to the patient’s body and then when the pressure inside the chamber increased, it compressed the patient’s chest and forced them to exhale. But the machines were bulky and restricted a patient’s ability to move. So, when positive pressure ventilators were developed in the 1950s, the technology caught on. Patients were not restricted, and caregivers could better examine them. Modern ventilators use either a tracheal tube or mask to apply positive pressure and inflate the lung during inspiration.

Prediction and Control of Response Time of the Semitrailer Air Braking System

02-12-02-0011

5/9/2019

The response time of the air braking system is the main parameter affecting the longitudinal braking distance of vehicles. In this article, in order to predict and control the response time of the braking system of semitrailers, an AMESim model of the semitrailer braking system involving the relay emergency valve (REV) and chambers was established on the basis of analyzing systematically the working characteristics of the braking system in different braking stages: feedback braking, relay braking, and emergency braking. A semitrailer braking test bench including the brake test circuit and data acquisition system was built to verify the model with typical maneuver. For further evaluating the semitrailer braking response time, an experiment under different control pressures was carried out. Experimental results revealed the necessity of controlling the response time. As a result, a braking pressure compensation system was designed through adding intake and exhaust solenoid valves to the

He, Ren, Xu, Chang