Bosch new micro-mechanical sensor
The DRS MM5 is 60 percent smaller than its predecessor

March 2010 – Robert Bosch GmbH,  Stuttgart, Germany:

Bosch is the first company in the world to start series production of a new sensor cluster that measures both the yaw rate around the vertical axis and lateral and longitudinal acceleration in one single sensor module.

Compared with its predecessor – the DRS MM3 – the new cluster is up to 60 percent smaller, which significantly simplifies integration into the vehicle.

The DRS MM5, Bosch's new micro-mechanical sensor cluster, delivers data to safety and assistance systems, such as the electronic stability program (ESP®). It is compatible with the current DRS MM3 variant, and can therefore be used in existing series projects without any complex or expensive applications.

Despite its highly integrated design, the DRS MM5's signal quality continues to meet the very high standards for dynamics and precision that have to be fulfilled for systems such as ESP® or “Hill Hold Control.”

For the measurements the sensor cluster uses measuring elements in surface micromechanics. Bosch developed this manufacturing process, and was the first company in the world to apply it industrially.

The yaw rate sensor's measuring element works according to the Coriolis principle, i.e., it utilizes the inertia force of an oscillating mass in a rotating system.

Due to the high resonance frequency of 15 kilohertz and the closed drive and evaluation unit, the yaw rate element is very insensitive to mechanical interference.

Acceleration is measured on the basis of the capacitive change in the micromechanical structures.

The sensor module further developed in the DRS MM5 guarantees excellent offset stability over wide temperature ranges and long periods: for acceleration measurement ±0.1 g; for yaw rate measurement ±3 degrees per second.

The digital signal processing also adjusts the signal bandwidth and reduces noise.

The safety and monitoring concept is also integrated in the sensor module. As with the DRS MM3, it also covers the entire signal chain: the measuring element, the evaluation electronics, and the microcontroller.

For the first time, the sensor signals can be issued via a standard CAN interface with a variable signal update rate, which is integrated in the sensor module.

They are therefore also available for all other functions and systems in the vehicle.