Automotive: test bench and production control
Fully automatic paint defect inspection of car bodies and attachments
Particularly with shiny surfaces, a faultless production chain is expected in order to lend a sophisticated visual appearance to the final product. For fully automatic defect detection on car bodies and attachments, the reflectCONTROL inspection system is used. The system projects a striped pattern onto the surface. Deviations caused by defect are recorded with two cameras and evaluated via software.
Recommended sensor technologyFully automatic surface inspection of painted car bodies
Detecting surface defects
As well as the visual requirements, instrumentation panels also have to fulfill functional and security requirements. Often the passenger airbag has a predetermined breaking line which is generated using a laser. This »weak point« ensures the safe opening of the airbag at the predetermined breaking line. Sink marks may appear, which can be recognized under certain light conditions. In order to recognize these defects, surfaceCONTROL inspection systems are used which enable fast and objective evaluations to be made of the characteristics of any shape deviations, both on grained and smooth surfaces.
Recommended sensor technologyInspection of diffuse reflecting surfaces
Monitoring the sheet metal infeed during pressing
During forming in the pressing plant, the presence detection and the detection of the exact sheet metal position are required. Therefore, laser triangulation sensors measure on the sheet between the dies. The challenge here is to achieve high measurement accuracy in tight spaces despite oil mist, vibrations and shocks. Since the measuring gap is very small, the diameter of the laser must be correspondingly low.
Behavior of the combustion engine in the test bench
Eddy current sensors from Micro-Epsilon are considered as proven measuring instruments in the test bench of combustion engines. In towing mode as well as in the firing mode, the sensors detect different quantities which contribute to the improvement of the engine characteristics. In particular, the high measuring accuracy provided under harsh conditions in the engine distinguishes the eddyNCDT eddy current sensors.
Gap measurement in aluminum die casting processes
In aluminum die casting, liquid aluminum is poured into molds under high pressure and at high speeds. The high pressure acts on the closed mold and pushes it apart, which is why splinters and burrs might occur during casting. In order to measure the pressure-induced movement of the molds, eddy current sensors detect the change in distance. These robust sensors provide reliable measurement results despite high temperatures, ambient pressure and a dirty measuring gap.
Measuring the brake disc deformation (Disc Thickness Variation)
With the capaNCDT DTV, Micro-Epsilon has developed a product range that is specifically used for non-contact detection of the Disc Thickness Variation. Thickness measurements of brake discs can be carried out in test benches, in road tests or in car repair shops using non-contact, capacitive displacement sensors, which detect the thickness of the brake disc from both sides.
Recommended sensor technologyMeasuring Disc Thickness Variation
Road tests - Detection of the brake temperature under load
The temperature behavior of brakes plays a major role in vehicle development. In particular, the duration of heating and cooling of the brake discs provides information about the efficiency of the brake system. In test bench and road tests, non-contact temperature sensors from Micro-Epsilon measure the temperature development during braking. The compact design and the short response time of the pyrometers enable universal use in test bench and road test applications.
Recommended sensor technologyInfrared temperature sensors for universal measurements
Gap measurement in robot-based assembly
In modern production lines, scanCONTROL laser scanners are used to reliably inspect the gap sizes of the car body quickly and consistently. Thanks to surface compensation, measurements are possible on a wide variety of body paintworks.
LED color inspection of vehicle lights
Color and intensity of vehicle lights must be reliably inspected prior to assembly and delivery. Homogenous distribution of light should also be ensured with fluctuating LED batches. The colorCONTROL MFA is a special LED test system designed to test inaccessible and widely spaced test specimens. Optical fibers enable simultaneous measurement of up to 20 measuring points.
Recommended sensor technologySensor systems for LED color and intensity tests
Position detection of car bodies in the processing line
Before a car emerges from a bodyshell, it passes through numerous stations within the production, in which fully automatic processing steps are carried out. In order to enables the processing robots to recognize the exact position of the car body, several laser triangulation sensors measure the car body and transmit the position data to the robot controller.
Color inspection and sorting of supplier parts
Before installing front aprons, Micro-Epsilon color sensors check if the color of the attachment matches the body color. Different color groups can be defined to cover all coatings.
Monitoring embossment depth
Embossed serial numbers enable worldwide unambiguous identification of, for example, car body shells. For increased safety measures (e.g. in case of theft), car body IDs are punched into the vehicle frame. Therefore, the depth of the embossment is a critical factor.
This is why embossing machines operate using optoNCDT 1420 laser triangulation sensors from Micro-Epsilon. These determine the precise distance between the embossing tool and the component. Based on these distance values, the tool can be positioned correctly. After the embossment is finished, the sensor measures the profile of the embossment and ensures that all characters are embossed to the required depth.
Request download linksApplication "Monitoring embossment depth" (PDF, 83 KB)
Inline burr measurement on sheet edges in body manufacture
In order to avoid corrosion, continuous and error-free corrosion protection is a critical factor in the painting process. As the thickness of the applied painting on burrs can only be determined under challenging limitations, it is a decisive advantage that the burrs are recognized early in the production process before the corrosion protection and other paint layers are applied.
In contrast to fixed solutions that enable a random test, Micro-Epsilon offers its scanCONTROL 2910-10/BL Plug & Play system which provides the required precision with its high point resolution of approx. 8µm along the laser line in order to recognize burrs reliably even during inline measurements.
Request download linksApplication "Inline burr measurement" (PDF, 168 KB)
Distinction of brake discs
When processing car brake discs, the correct brake disc must be chosen before each stage of production in order to assign them to the manufacturer's different models. Laser scanners are used to recognize and classify the brake discs. The challenge of brake disc distinction is that the test objects are the same with regard to form, height and diameter. The gapCONTROL laser scanners are used for 100 % recognition and subsequent sorting. The only distinctive feature is a gap between two ventilation blades that signifies the respective models of the manufacturer.
Request download linksApplication "Distinction of brake discs" (PDF, 81 KB)
Valve lift measurement in the MultiAir cylinder
The MultiAir cylinder procedure patented by FIAT / Schaeffler controls individual valves independently of the camshaft. An electro-hydraulic control system provides fully variable valve control.
Therefore, the stroke and the opening/closing times of the inlet valve are freely controllable. This reduces fuel consumption and CO2 emissions with a simultaneous increase in engine performance and torque.
During the end-of-line inspection of the MultiAir components, a test bench simulates the conditions inside the engine. Eddy current sensors from Micro-Epsilon measure the exact valve lift.
Recommended sensor technologyInductive sensors (eddy current) for displacement, distance & position
Request download linksApplication "Valve lift measurement in the MultiAir cylinder" (PDF, 65 KB)
Color comparison between parking sensor and body shell
Car attachments such as parking sensors are painted separately. However, during assembly there must be no difference in color between the parking sensor and the bumper, which means the two colors must be identical. The colorSENSOR sensor from Micro-Epsilon enables a direct color comparison between the parking sensor and the rear bumper.
Request download linksApplication "Color comparison between parking sensor and body shell" (PDF, 117 KB)
Color recognition for seams in automotive interiors
A well-known German car manufacturer relies on poka-yoke mechanisms for assembling interior components. The poka-yoke process prevents product defects due to random human errors and ensures that all parts are assembled correctly. However, similar types of component often have different colored seams, which is why error prevention is critical. Previously, these checks were performed manually - experts inspected the seams visually. Micro-Epsilon’s colorSENSOR color sensors are now used to automate this process and to make it more efficient.
Request download linksApplication "Color recognition for seams in automotive interiors" (PDF, 95 KB)
Vibration displacement measurement in road tests
With cars, tests on the running gears form the basic requirements for driving safety. Here sensors are needed which can also withstand the high demands of road tests. As an example, draw-wire sensors are mounted in parallel to the shock absorbers for the vibration displacement measurement and the data is recorded for varying road-surface quality. The displacement signal obtained is differentiated to give the vibration velocity and vibration acceleration.