Resultado final
The results of Task 3 the also comprise the design of the vehicle concerning best pedestrian protection. For this reason different numerical simulation are done to assess the vehicles behaviour and possible design characteristics having influence on the pedestrian safety. The result is the knowledge about different systems and design variables to influence the pedestrian safety of new kind of three wheeled vehicles.
Construction of two scale 1:4 models:
1: complete model with rapid prototyping technology (stl) to check the cad-datas of the outside surfaces.
2: frame model including wheels and suspensions, seats and frame brackets to check package dimensions and interfearences.
Both models are in use for exhibitions and events.
Constructing of a fully functional prototype according to all drawings and CAD-Datas (reproducible prototype).
Vehicle is running with CNG.
Electrical devices are working (Headlights, rear lights, turn signals, signal-horn, dashboard...)
Vehicle is under testing and showed to the public.
Within the design phase of the vehicle different assumptions are made concerning the dimensioning and the package of the vehicle. To be able to assess these ideas it is helpful and also necessary to have a 3D visualisation of the vehicle. For this reason a seat reference model was build up. With the help of its three dimensional geometry it is possible to assess the proportions of CLEVER and to make modifications very early in the development process. One result of WP 3 is the seat reference model which was build at the facilities of the TUB.
In the scope of Task 6 various crash test will be conducted. These tests comprise frontal impact against a rigid wall and side impacts against another car. The results of these tests are designed to help to assess the results of the numerical simulations on the one hand and to determine the safety of a small urban vehicle on the other hand.
Within Task 3 the vehicle structure has to be designed and dimensioned for best self and collision partners protection. In the scope of this work different numerical simulations are done to get knowledge about the behaviour of this new kind of vehicle. In the particular case the special front end design of small vehicles has to be investigated. The result is the information gathered about the crash behaviour of three wheeled vehicles and strategies to get best collision protection for the driver as well as for the collision partner.
The result describes development of a tilting three wheeled chassis to enable small wheeltrack, with one wheel at the front and two at the rear. The main vehicle cabin tilts with the front wheel using an active control system operating hydraulic actuators.
Potential applications:
- City vehicles
- Other classes of car
- Light goods vehicle
- Other land vehicles, especially where upright stability is required, or rollover is common
End users:
- Automotive industry
- University teaching courses, internal and industrial.
Main innovative features:
- Servo-operated hydraulic system responding to driver inputs and vehicle attitude using modern control approach.
- Vehicle dynamics largely adjusted using software modifications - Current state of the art uses mechanical linkages to operate hydraulic valve, so vehicle dynamics vehicle will be improved.
Chassis dynamics (suspension, geometry, tyres) developed in harmony with control system.
Majority of development performed with numerical simulation.
Vehicle maintains direct steer link to front wheel and therefore driver feel of the road.
Development in tyre and steer geometry achieves the correct feel.
Failsafe operation captured in control algorithm, and backed up by mechanical device (confidential).
Hydraulic system sized to exact power requirements for efficient operation. Use of accumulator and variable unloading valve ensures minimal engine power interruption when pump is online.
Small number of hardware components for tilting system because of direct steer hence low cost.
Potential barriers:
Difficulties in achieving correct steer torque (hence driver feel) for all driving conditions.
The CLEVER vehicle should be base for a review of the monitoring rules for the CO2 fleet consumption. The current situation of a case by case decision does not allow any strategic planning reliability for the development of alternative vehicle concepts below category M1 vehicles. The monitoring rules for three-wheeled vehicles have to be specified according to the CLEVER vehicle concept, in order to facilitate the planning and to permit the construction of such a vehicle.
Construction of a fully functional prototype vehicle for chassis systems and tilting system development and tuning. Used during the project period to validate vehicle models and refine tilting system before implementation on show/trim vehicle prototype. Initial experimental results disseminated in PhD theses of Drew and Barker (2006, University of Bath).
Market Potential:
The share of trips of residents which can be shifted to the CLEVER vehicle has a range between 2 and 13% indicated by the results of a two phase survey in the case cities Graz and Thessaloniki, which indicates quite a respectable market potential. This modal shift comes mainly from car drivers but one third can be originated also from public transport. The size of this range is caused by different influencing factors. On the one hand very important are the existing traffic conditions as the parking and congestion problem. A high lack of parking spaces and a high load of traffic in central parts of the conurbations increases the potential of the CLEVER vehicle. On the other hand the quality and standard of the alternative modes relating to the car has a strong influence on the market potential of CLEVER: The availability of alternative modes on a high quality level reduces the potential share. That leads to the conclusion, that the CLEVER vehicle is an interesting alternative in cities with big car traffic problems. It has to be stated that also the cultural and climatic background plays a role. It seems that the Mediterranean countries have a greater potential for CLEVER as it can be observed also for motorbikes. The user costs of cars (e.g. fuel price and road pricing) and the purchase costs of the CLEVER vehicle are an additional influencing factor for the potential share of the modal split. Accompanying promoting measures have a less effect on the use of CLEVER than expected. The range of the potential differs between the scenario with and without accompanying promotion measures for CLEVER (e.g. allowance of use of bus lanes for CLEVER, designated parking spaces for CLEVER, exception of road pricing) only up to 2 %. The potential user group of CLEVER consists mainly of male persons in the age group between 45 and 65 years.
Economic and Environmental Effects:
The main important benefits of the CLEVER vehicle are the reduction in exhaust gas emissions and fuel consumption. The reduction has a potential range up to 17 % dependent of the single components of pollutants and the realized mode shift to CLEVER. The implementation of the CLEVER vehicle lets expect a small decrease of the travelled journey time. The potential reduction for CO2-emissions and fuel consumption indicates a range up to 12% for the analysed scenarios. There is no significant change in the indicators of traffic safety and the total economic costs, but there is a remarkable benefit from the side of public household: the implementation of the CLEVER vehicle doesn t require huge public investments, it is mainly based on private investments.
Attitudes of Policy Makers Towards CLEVER:
An international expert survey has shown, that policy makers and transport experts have a mostly positive attitude towards CLEVER - mainly based on the contribution to reduce air pollutants and CO2 emissions as well as the innovative vehicle aesthetic design. They welcome a new vehicle like CLEVER on the market, but they see no urgent need to give specific incentives and support for the implementation of the CLEVER vehicle, because the positive effect of these accompanying measures for the CLEVER is not respectable enough to argue such activities towards the public.
Vehicle manufacturers are forced to apply lightweight solutions by a lot of needs and legal conditions. They are applied in order to save weight and resources, to improve the driving performance of vehicles and also to demonstrate and exploit technology progress. The Aluminium space frame consists of aluminium profiles, which are connected by cast aluminium connection nodes.
Nodes can also include mechanical functions like supports for hinges, locks etc. Frame strictures of sports cars are often produced from simple or standard aluminium or using large section aluminium profiles in combination with panels and formed parts. In order to realize a maximum fuel consumption of one litre per 100 km in a two seater motorcar prototype, Volkswagen realized a lot of outstanding innovative details.
This innovative prototype vehicle demonstrates the weight saving potential by a consequently use of new lightweight materials and lightweight design. Mechanical joining systems are Screws and threads with washers, all kinds of rivets and joints by material forming. The clinch method is a new cold joining technique. In coherence with increasing aluminium application in the automotive industry also welding technologies were developed intensively. Adhesive bonding methods emerge more and more to common joining methods in the automotive industry. Adhesives can also seal up the joints.
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