Car wash automation and quality control with machine vision
Max Reijngoudt
Technological developments mean that more and more processes are being automated. One place where we also see this more and more often is car washes. Over the years, car washes have become increasingly sophisticated and equipped with the latest technologies to work more precisely and efficiently. In this article, we explain how we can use machine vision camera technology to further automate car washes.
An example where machine vision camera technology can help a car wash is in detecting car rims. In a car wash, the rims of cars are often washed with high pressure, it is important that this only touches the rims and not the rest of the chassis of the car. Previously, this was often done by one person and the person himself had to keep an eye on whether the rims were clean and whether the rest of the car was not damaged. Now that many of these processes are automated, this can be done faster and better with machine vision. This article gives an example of a possible machine vision camera set up that you can use for this type of application.
Table of contents
Machine vision camera selection for car wash automation
Through our web shop VA-Imaging.com we offer a broad portfolio of machine vision cameras, lenses and accessories. Our account managers are happy to help you select the right hardware and software for your projects, asking specific questions to find out which set up best suits your specifications.
When applying for the car wash, the customer indicated that they wanted to be able to see details of about 0.1mm on a rim with a maximum diameter of 23 inches (58.42 cm). This means a camera with a resolution of at least 2100 x 1770 pixels is needed.
The customer had no preference for a particular camera interface but indicated that the distance between the camera and PC is short. We recommend to customers that if the distance between the camera and PC is shorter than 4.6 meters, it is best to use a USB3 camera.
The next step is to determine the camera’s desired shutter type. Global shutter and Rolling shutter cameras work in a different way. We recommend to clients that if the camera or the object is moving, they should use a global shutter camera. If the camera and/or object is stationary, then a rolling shutter camera is recommended. Because cars sometimes pass by while there is still motion, with this application it is recommended to use a global shutter camera. The difference between global and rolling shutter cameras is further explained in this article from our Knowledge Center on the website.
A suitable camera that meets the above specifications would be the 5MP USB3 Camera ‘MER2-503-36U3C’. This 5MP camera is the best option for this particular application. Further specifications of this camera can be found on the camera's product page on the website. Furthermore, the datasheets of our cameras can be easily downloaded from our download page.
Calculating the correct lens to automate the car wash
A suitable set up also includes the right machine vision lens. We always use our lens calculator on our website for this calculation.
In the first step of the lens calculator, you need to enter the details of the camera. The resolution and pixels of a machine vision camera can be found on its product page.
Next step is to enter the details of your project/application. The field of view is the entire area the camera should be able to image. The working distance is the distance between the camera and the object. In this application, the working distance was variable but preferably between 1 and 2 meters.
At the third step, you can see which focal length of the lenses is recommended. In this case, this is a 16mm lens. In the previous step it is also possible to specify a desired focal length already. If you define this in advance, the working distance is automatically adjusted accordingly.
In step 4 of the lens calculator, you can see your field of view and working distance when using a 16mm lens. A suitable lens for the MER2-503-36U3C camera would be the 16mm C-mount lens 'VA-LCM-5MP-16MM-F1.4-015'
See the screenshot for all the lens calculator values filled in for this application.
Machine vision Accessories
Since the cameras will be placed in a car wash, they should also be protected from water and dirt. Therefore, we also recommend using an enclosure for the camera. Our aluminium machine vision camera housing is a good option for this. Check our article if you want more information on choosing a machine vision enclosure for your application.
Industrial LED lighting
A machine vision set up is not complete without adding industrial LED lighting. Since the environment can be humid and the camera also needs to be protected, so does the lighting.
VA Imaging recently released a new LED spotlight and, like the housing, it is IP67 certified. IP67 means that the lighting is intended to be resistant to dirt and water.
This LED spot features user-changeable optical lenses (90 / 60 / 30 degree) and therefore offers a suitable solution for versatile vision applications where flexibility is required. More information on this LED spot can be found on the product page, on the website.
Software for car wash automation
An important step is choosing your machine vision software. The cameras should be controlled with our proprietary DAHENG Software Development Kit. This can be easily downloaded for free from our website. With the SDK, you can easily adjust the parameters of the camera to a desired value.
For further inspection, the customer chose to write their own software using the Python programming language. More information about using Python with Daheng Imaging machine vision cameras can be found in this article, 'How to use a python sample to acquire images using Pycharm'.
Contact us for questions or assistance
If you have any questions or would like to get in touch with the account managers at VA Imaging for assistance with your project, our team is ready to help. Whether you are looking for tailored advice on selecting the right hardware or need guidance on the best machine vision setup, we are here to support you. Simply fill in the form below, and we will get back to you within 24 hours.
