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Technical Paper

Design of a Mock-up for Supported Ingress/Egress Using a DHM

2009-06-09
2009-01-2268
This paper presents the usage of the Digital Human Models (DHM) PCMAN and RAMSIS to determine parameters for a supported ingress and egress on a mock-up. Sports cars with lower seating positions show occurring difficulties among older drivers during ingress/egress. To equip sports cars with higher seats or narrow door sills seems limited due to design aspects. Therefore the idea of an ingress/egress support system arose. To build a mock-up, it needs specific dimensions already in the CAD design phase. Here DHM-systems are utilized. As no similar systems are known, no ballpark figures for trajectories of the seat or movement ranges can be derived from literature. Therefore pre-tests were done with a simple manually moved seat. Test persons showed high acceptance and discomfort reduction. In order to design a proper testing environment for repeatable and reliable results, a variable seat with electric motors is built into a mock-up with a package of a sports car.
Technical Paper

Statistical Approach to a Model-based Anthropometry Description

2009-06-09
2009-01-2298
This pilot study shows an approach to generate a man-model-based anthropometry description. With the video-based software PCMAN, which has the same model structure as the DHM Ramsis, the individual anthropometry of a subject can be measured manually and expressed by a set of 476 model parameters. On the basis of 140 available anthropometric data sets statistical analysis has been done and four factors could be identified which allow for a good general description of human body shapes. Having shown the applicability of the approach the described method would now have to be applied to large, high quality data sets from body scans.
Technical Paper

Sight Analysis with ‘RAMSIS Cognitive’: Step II

2009-06-09
2009-01-2295
The perception of visual information is the major input requirement for the psychological cognition process. The quality of perception of visual information is impaired by the geometrical and optical conditions of the displayed information. This concerns all technical information of the car as instruments, optical indicators, telltales and control displays. The international widely-used 3D-Man-Model System RAMSIS receives some additional functionality for analysis and practical design to simulate these viewing conditions in the car. These new RAMSIS functions include methods for the analysis of sight shadows, limits of visibility of liquid crystal displays, the time of focus shifts of the driver and the modelling of the optical parameters of head-up displays. These capabilities will enable a RAMSIS user to allow for (degraded) visual performance when designing the rising number of user interface displays in cars and airplanes.
Technical Paper

Predicting Long Term Riding Comfort in Cars by Contact Forces Between Human and Seat

2005-06-14
2005-01-2690
In this paper a project is described on finding a relationship between discomfort and contact force distribution between human and seat. In the first step experiments were conducted to find correlations between pressure and discomfort. In the second step these findings were validated for long term discomfort. The gained knowledge provides the possibility to check the long term riding properties of a car seat by taking the pressure distribution which takes only a few minutes. Furthermore, pressure distributions which are computed by digital human models can be evaluated with this knowledge.
Technical Paper

Objectifying the Comfort of Car Seats

2006-04-03
2006-01-1299
This paper concerns a former experimental study of the Lehrstuhl für Ergonomie of TU München, where in the first step correlations between pressure and discomfort were found for the seat pan. In the second step these findings were validated for long term discomfort. Now an additional correlation for the back should be found, which is essential for later research. In this context tests conducted before should now be confirmed and validated by another seat comfort model with a higher number of subjects and a long term test, too. Interesting part of this study will be the intercorrelation between seat pan and back.
Technical Paper

New Features for the Sight Analysis with RAMSIS

2008-06-17
2008-01-1877
Ergonomic product design can be divided into the parts of physical ergonomics (anthropometrics) and cognitive ergonomics. I regard to the visual cognition, the anthropometric and cognitive ergonomics are very closely connected. The visual cognition process is based on physical as well as psychological components. The information processing in the brain needs the visual perception with the eyes. This visual perception needs some optical attributes for good viewing conditions of the eye. The international widely-used 3D-Man-Model System RAMSIS receives some additional functionality for analysis and practical design of to simulate these viewing conditions in the car. These new RAMSIS functions include methods for the analysis of reflective glare, visual acuity, reading precision, visual fields, limited accomodation, glasses, progressive addition lenses and electronic displays.
Technical Paper

Discomfort Model for Arm Movements

2008-06-17
2008-01-1872
The group human modeling of the Lehrstuhl für Ergonomie at the Technische Universität München has the aim to develop an autonomous digital human model. On this way a general dynamic discomfort model for posture and movement shall be developed in order to predict the perceived discomfort of a human during a task (e.g. lifting of a weight). This can be used to provide suggestions for the concept of a new product. Using a discomfort model in the dynamic situation that is based on force and posture is unique and leads to a new quality, because the rate of the force or torque potential of a person can be taken into consideration. Motion prediction under load will be improved. This can help to solve current questions of automotive companies like ingress/egress. In this paper a discomfort model for an arm movement is described and generated in the context of a lifting task. It is derived from a static model and accounts for the force level of a subject.
Technical Paper

Spine Load in the Context of Automotive Seating

2007-06-12
2007-01-2485
In modern society the automobile is an essential companion in everyday life. Be it commuting to and from work or during our leisure time - every week most of us spend many hours sitting in their car. In this context the seat is the main interface between the human being and the automobile itself. Functioning well, this close relationship can foster the well-being of the passenger and raise his spirit; being flawed it can otherwise cause severe pain in the back after a longer journey. Thus, for car manufacturers, the aspects of seat comfort are becoming more and more prominent in distinguishing themselves from their competitors. Despite its importance the development of comfort parameters in automotive seating is still being consigned to the subjective judgements of a poor number of seating experts or randomly selected test subjects.
Technical Paper

Simulation of Target Directed Movements within the CAD-Manmodel RAMSIS

1999-05-18
1999-01-1919
The ergonomic design of automobiles has changed over in the last years. It is increasingly being transferred from the usage of two-dimensional templates of the human shape to computer-aided manmodels. So far these models were mainly used for static anthropometric investigations on the drivers workplace. Dynamic questions can be answered only very insufficiently. In the context of this work a methodology was developed to precalculate target directed human movements in a motor vehicle environment with the CAD-manmodel RAMSIS. A new two-piece model was developed. In this model dynamic boundary conditions, so called dynamic restrictions, for any movement in a car are determined, concerning outside parameters. In the following, the entire bodyposture is determined by a statistical posture probability model, considering these dynamic restrictions. A control theory of human movements was derived from the field of neurophysiology.
Technical Paper

Human-model Based Movement-capturing Without Markers for Ergonomic Studies

2001-06-26
2001-01-2113
This paper presents a movement measurement system to acquire human motion data without markers. The system uses an accurate human man model as template to measure, based on image processing, movements. This method enables quick ergonomic measurements because no preparation of a subject with markers or special clothes is needed. All results which are achieved with this system are conform to the used man model and can be directly used for human modeling. Exemplary three investigations are presented concerning in-vehicle head and arm movements and riding a bike.
Technical Paper

Measuring of Human Anthropometry, Posture and Motion

1999-05-18
1999-01-1913
An electronic measurement system called PCMAN has been developed by the Institute of Ergonomics of the Technische Universität München to carry out body and posture measurements. PCMAN can produce model-like, three-dimensional images of a body quickly, reliably and precisely. The resulting data can be computer-processed using the CAD human model RAMSIS. PCMAN works with several images taken from different directions. From these, three-dimensional coordinates can be calculated by measuring corresponding points on the frames. The RAMSIS grid model can also be fitted into the subject's body measurements and posture. This is done by over-laying RAMSIS on the bitmaps of the subject and adjusting it to the subject's exact shape by changing the body surface and the location of the joints. PCMAN works with standard cameras operating at 25 frames per second.
Technical Paper

Simulation of Complex Movement Sequences in the Product Development of a Car Manufacturer

2003-06-17
2003-01-2194
Cutting development times in car manufacturing means bringing forward the knowledge processes. Simulations based directly on CAD data reduce or replace time-consuming hardware loops significantly and therefore make a significant contribution to this. Ergonomic product design is an area that is challenged as far as the further development of virtual methods is concerned. Simulation of the static and quasi-static positions of passengers inside the car is the current state of the art in ergonomic product design. For this reason, interest is strongly focused on the simulation of complex movement processes within the context of enhancing simulation tools. For the car manufacturer, the manner in which people enter and leave the car is of particular interest. Getting into the car is the customers' first actual contact with it. It may also develop into a serious problem for car drivers, as they get older.
Technical Paper

Influence of Forces on Comfort Feeling in Vehicles

2000-06-06
2000-01-2171
When investigating the posture comfort in vehicles two important influencing factors can be distinguished: In order to evaluate these influences a combined laboratory-field-experiment was carried out. A real car was equipped with cameras to record the body posture and the joint angles. The static forces exerted by the driver on his contact points were recorded in a corresponding mock-up. The forces to maintain the body posture were calculated. The following results were found:
Technical Paper

Predicting Overall Seating Discomfort Based on Body Area Ratings

2007-04-16
2007-01-0346
For car manufacturers, seating comfort is becoming more and more important in distinguishing themselves from their competitors. There is a simultaneous demand for shorter development times and more comfortable seats. Comfort in automobile seats is a multi-dimensional and complex problem. Many current sophisticated measuring tools were consulted, but it is unclear on which factors one should concentrate attention when measuring comfort. The goal of this paper is to find a model in order to predict the overall seating discomfort based on body area ratings. Besides micro climate, the pressure distribution appears to be the most objective measure comprising with the clearest association with the subjective ratings. Therefore an analysis with three different test series was designed, allowing the variation of pressure on the seat surface. In parallel the subjects were asked to judge the local and the overall sensation.
Technical Paper

Computational Approach for Entry Simulation

2006-07-04
2006-01-2358
A comprehensive experimental study was conducted to investigate human movements when entering a vehicle. The primary goal of this study was to understand the influence of environmental changes on entry motions selected by a driver to enter a vehicle. The adjustable hardware setup “VEMO” (Variable Entry Mockup) was used for the experiments. With VEMO it is possible to simulate different types and classes of vehicle configurations. Around 30 test persons of different anthropometry participated in the experiments. The visual measurement system VICON was used for motion capturing, motion data cleaning and biomechanical analysis. The results corroborate the theory of leading body parts (LBPs) i.e. body parts that control targeted movement of the entire body. It could be demonstrated how motion patterns of LBPs, including spatial and dynamic characteristics such as orientation and velocity, respond to modifications of the geometrical environment.
Technical Paper

Ergonomic Layout Process for a Driver Working Place in Cars

2006-07-04
2006-01-2313
During early phases of interior car layout a lot of different aspects have to be considered like crashworthiness, regulations, philosophy of the company etc.. Ergonomic aspects do not always play the most important role in these cases. Since aspects of comfort in cars are getting more and more important in nowadays these aspects should be taken into account very early in the interior car layout process. This paper shows a way to design the interior layout of a car from scratch for a good postural comfort for all anthropometries with the aid of a digital human model (RAMSIS). The novelty of this approach is to use the digital human model to design the interior and not to verify or correct an existing one.
Technical Paper

From Aviation down to Vehicles - Integration of a Motions-Envelope as Safety Technology

2006-02-14
2006-01-1958
Some systems like the ESP already exist to support the driver for the stabilization of the vehicle. But the next generation of active safety system will have to deal with a wider environment of the vehicle, to go closer to the limit of the vehicle dynamic etc. With such a complexity the systems will also have to take into account their own limits and to reduce their actions when they have a low confidence, e.g. when sensors are degraded. This article describes firstly a virtual driver and secondly a decision control that fuses their command depending on their confidences in order to improve the reliability of the command level.
Technical Paper

SPARC Technology - Concept of a New Safety Relevant Architecture

2005-11-01
2005-01-3514
This paper introduces a concept of predictive active safety by means of a full redundant architecture with the driver, from the perception of the environment to the vehicle controllers. The bottleneck of the current driver-vehicle association will be analyzed first. Then a virtual driver and the safety envelope of the different maneuvers will be described. A decision control will be presented that it matches the driver's command in this safety envelope. It is designed to give adequate feedback to the driver and can safely perform the command to the optimum of the chosen maneuver.
Journal Article

Emocard – An Approach to Bring More Emotion in the Comfort Concept

2008-04-14
2008-01-0890
In modern society the automobile is an essential companion in everyday life. Be it commuting to and from work or during our leisure time – every week most of us spend many hours sitting in their car. In this context the seat is the main interface between the human being and the automobile itself. Functioning well, this close relationship can foster the well-being of the passenger and raise his spirit; being flawed, it can cause severe pain in the back after a long journey. Thus, for car manufacturers, the aspects of seat comfort are becoming more and more prominent in distinguishing themselves from their competitors. Despite its importance, the development of comfort parameters in automotive seating still is consigned to the subjective judgements of a small number of seating experts or randomly selected test subjects.
Technical Paper

Sensitivity of Human Pressure Feelings while Sitting

2004-06-15
2004-01-2140
To describe feelings of discomfort while sitting, many experiments have been conducted to find a link between interface pressure on the seat and the feelings of discomfort of test subjects. Most of these experiments found no relation or correlation between discomfort and pressure while others actually found a relation. A question which arose was how sensitive the human body is to pressure differences during sitting. The attempt of this study was to determine the sensitivity to pressure for an area of the thigh. Therefore a test stand was designed allowing the variation of pressure on an area of a thigh during sitting. In parallel, the subjects were asked to judge the pressure sensation. By analyzing the frequencies of answers given by the test subjects, a curve could be derived which describes the sensitivity of pressure sensation. In this paper the test stand, the test procedure, the results and further experiments will be discussed.
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