Modernization of Existing Chassis Dynamometers - Testing Solutions for Passenger Cars
Modernization of Existing Chassis Dynamometers
The basic modernization focuses on the upgrade of controller components to ensure efficient usage of the equipment. One possibility is the upgrade by an accuracy package to achieve a more precise force and speed measurement chain for higher control and measurement accuracy. A power package is also available.
Benefits at a Glance
- Higher availability of testbed.
- Improvement of service and spare part availability.
- More efficient use of equipment.
- Precise force and speed measurement for higher control and measurement accuracy.
Basic Modernization Package
A technical solution for the modernization of a chassis dynamometer is prepared following an engineering study. The existing chassis dynamometer is analyzed in detail and a specification of the necessary changes prepared. The detailed requirements for the modification are handed over to the AVL modernization team
The technical solution from the engineering study is taken as the basis for the electrical engineering. The original documentation is reviewed and part lists are created. Then the interface predefinition is prepared for the component selection and design. Software components are prepared prior to the intervention as a basis for the commissioning on site.
With the modernization to VECON the following advantages get effective:
- Robust industrial design leads to higher testing availability.
- Due to the high sampling rate, excellent control quality is achieved.
- A sophisticated control concept with high repeatability and accuracy in road load simulation (feed forward control) is established.
- Upgrading the controller hardware ensures quick response time on service and spare part availability.
- The VECON controller has all features, like graphical user interface, data logging possibilities and an AK interface to be controlled by a host computer.
- The modernized electrical parts of the chassis dynamometer are again "State Of The Art"; all used parts are well established industrial components based on Profibus-DP.
AVL covers the electrical installation and commissioning of the modernized components, especially the installation of the cables between cabinets, the control room and the chassis dynamometer. The final acceptance procedure completes the commissioning of the modernized components. This work is carried out by AVL service technicians. The final part of the modernization is the electrical (and mechanical) documentation of the modernized components.
Different versions of the accuracy package is available.
- A speed sensor conversion kit which provides an accurate and reliable speed measurement. The quality of the speed signal has significant influence on the quality of the road load simulation. A new high-resolution 2-channel speed pick-up will be installed on the existing chassis dynamometer.
- A force sensor conversion kit which provides an accurate and reliable force measurement. The quality of the force signal has high influence on the quality of the road load simulation. A new high precision load cell will be installed on the existing chassis dynamometer. The tractive force of a cradled mounted dynamometer is measured by this load cell. The existing design is modified in accordance to the new load cell. The load cell type will be chosen at the beginning of the project.
- A control sensor kit which allows to monitor special chassis dynamometer functionalities. The quality of the sensors has high influence on the quality of the chassis dynamometer monitoring functionality. The control sensor kit will be chosen at the beginning of the project. Each functionality of the existing chassis dynamometer should be monitored by a control unit. This also could mean a need to install new sensors, which weren't present before.
You can profit from the advantages by exchanging a power cabinet:
- Robust industrial design
- Latest converter technology
- Easy and fast exchange of single components through splitting the drive in modules
Additional components in the power cabinet for power supply of auxiliary equipment are installed. Chassis dynamometers which have auxiliary electric consumers (e. g. centering device) request additional power component from the power cabinet. This is necessary if the remaining power component is not sufficient (e. g. existing power component is malfunctioning). An additional auxiliary consumer may be installed and commissioned by the AVL modernization team. The functionality will be evaluated prior to the installation.
Example technical facts of an acoustic chassis dynamometer with four rollers and motors Speed synchronization results before the modernization.
Speed synchronization results after the modernization