Motec optimises production for digital cameras
Assistance systems for mobile working machines are often camera-based. Digital camera solutions have the advantage that they can be intelligently designed using the right software and controllers. The camera experts at Motec have been pro-active in facing this challenge and optimising their production systems to meet the requirements of future applications.

The requirements of the manufacturers of mobile working machines are constantly on the rise. In particular, the desire for comprehensive assistance systems can only be satisfied based on increasing digitalisation of agricultural and construction machinery and forklift trucks. These systems can include turning assistants for large vehicles that alert drivers to pedestrians or cyclists in the blind spot and thus help contribute to improved road safety. Additional active reversing systems or intelligent monitoring of the harvesting process in farming are other typical applications for intelligent video-based assistance systems.

Decades of industry experience
Motec from Hadamar is one of the leading manufacturers in the field of intelligent drive and process assistance systems. For more than 25 years, the company has specialised in the development, construction and production of quality camera monitoring solutions for mobile working machines. Motec systems are used in construction machinery, transport vehicles, agricultural machines, forklifts, communal and rail systems and military vehicles. The company specialises in particular in the individual adjustment of camera monitor solutions to meet customer or industry requirements.

As a partner to leading premium machine manufacturers, Motec recognised the potential of digital camera systems early and set up its own software development department specialising in driver assistance systems. As part of our own comprehensive digitalisation strategy, the company has recently digitalised and automated the production processes for the camera systems.

Maximum quality
This is necessary as the manufacturers of mobile working machines are increasingly demanding camera systems which meet automotive standards. Dr Tony Albrecht, R&D Director at Motec, explains: “Machine operators and their machine drivers are increasingly expecting the support systems they are familiar with from their cars. Even though the working machines are much bigger and more complex, they should be as safe and convenient to use as cars. So the demand for robust camera systems as the basis for a range of driver assistance systems has increased massively in recent years.” Motec recognised this trend and adapted its production lines and end-of-line tests to these quality requirements.

Digital camera systems need perfect image quality as the basis for further image processing. The focus, sharpness and alignment of the lenses must be at the maximum reproducible level to allow the data processing software to be adjusted and to work reliably. In order to guarantee this, Motec works with an Active Alignment testing and production system. This fully automated system guarantees maximum reproducibility and control of the camera and lens quality. At the same time, this system allows a substantial increase in unit numbers.

How does Active Alignment work?
The modern production system of a German manufacturer combines automated adjustment and optimisation with the ‘marriage’ of the lens with the holder module. Firstly, the lens and the holder are inserted into the Active Alignment system. The system then uses the saved characteristics, parameters and geometries to test the compatibility of the modules. This allows it to automatically prevent faulty pairings. The sticker is then applied to the holder with micrometre precision.

The portal then moves the measurement system to the focussing and joining process. A six -armed robot picks up the lens and inserts it into the camera holder. Focussed collimators are used to perfectly align and adjust the lens in order to achieve the best possible focus. The Active Alignment system also checks and calibrates the image tilting, the optical axle, the optical centre, the spectral sensitivity, the dynamic scope and all other quality-relevant parameters on the lens. Once this process is complete, the lens is inserted into the optimum position in the holder and the glue is hardened using UV light. The glue between the lens and the module is then hardened using thermal methods. This gluing process offers much more flexibility in terms of alignment than fixing the system using screws.

Another key feature of the Active Alignment system is the integrated defocussing of the lens. The glue applied shrinks during the hardening process. Motec’s extensive expertise in adjusting lenses has allowed it to calculate this contraction rate and factor it into the process. The lens is inserted such that the image parameters are perfectly balanced only once the glue has hardened completely.

This automated production system for the camera modules thus guarantees reproducible quality and characteristics which are critical for digital assistance systems in mobile industrial machines working on an increasingly autonomous basis. Dr Tony Albrecht adds: “Active Alignment production makes our already outstanding camera systems even better. At the same time, the process accelerates the focusing process by up to five times. This considerably speeds up the production process and means we can also offer our digital camera systems for production vehicles without compromising on quality.”

Digitalisation of assembly
As well as introducing the Active Alignment process, Motec has introduced a range of other measures in order to perfect its production processes. The production lines have digital feedback systems and automated assembly stations. This means, for example, the modules are always tightened to the perfect torque. If the assembly software detects an error in a component, it cannot be processed further until the error is resolved. At the end of the assembly process, a final inspection monitors all the assembly stages to ensure the product has been produced to Motec’s high quality standards. Overall, the camera monitor experts have adjusted their production processes to the excellent quality of their products and are thus prepared to face the challenges of the future.

 
 

Caption: When connecting the lens and the module holder as part of the Active Alignment process, the lens can be fitted flexibly, as can be seen from the gap in the right-hand image.

Caption: The tested and perfectly adjusted camera is removed from the measurement and calibration system.