Time-of-flight 3D imaging evaluation kit, with QVGA resolution

July 03, 2015 // By Graham Prophet
Featuring high frame rates, interchangeable optics, modular hardware architecture and advanced sunlight cancellation, Melexis has added support for its time-of-flight (ToF) sensing technology with the EVK75023 evaluation kit.

The kit supports the MLX75023 QVGA (320 x 240pixels) resolution ToF sensor that employs high dynamic range “DepthSense” pixels. This hardware platform enables implementation of more advanced human machine interfaces (HMIs).

Co-developed in association with Melexis technology partner BlueTechnix (maker of 3D depth sensors for the industrial market), the EVK75023 is a 130 x 105 x 60 mm board for assessment of ToF sensing capabilities under even the most challenging of application conditions, where the detrimental influence of ambient light variations must be addressed. Thanks to the embedded MLX75023 imaging device, it can deal with up to 120 klux of background light.

The EVK75023 has a high bandwidth Gigabit Ethernet interface, through which real-time 3D images are output at frame rates of up to 60 fps. These can be used to recognise complex gestures. Users can develop their own communication interface via a C-based API or via the Matlab SDK.

The platform consists four main elements:

- A pair of illuminating units - each with a set of six LEDs capable of producing a peak optical output of 10W.

- A sensor board - incorporating the MLX75023 sensor, a standard M12 lens mount plus objective with a field of view up to 60°, a quad-channel data converter and programmable logic (through which both the sensor and the LEDs are controlled).

- An ARM-based processing board - featuring an i.MX6x Freescale microprocessor, which is responsible for compiling the acquired ToF data then subsequently communicating this to a laptop, via the Gigabit Ethernet connection, for analysis.

- An interface board - on to which all of these different subsystems are placed.

“By using Melexis’ automotive-grade ToF offering, automobile engineering teams will be able to deploy HMIs which are robust enough to deal with difficult working environments, where they are exposed to dramatic alterations in light levels, while still hitting the necessary price points to ensure economic viability,” states Kristof Lieben, Application Engineer