3D Planarity and Measurements Inspection of Brake Pads

of Brake Pads with Pulsar (Application Report)

The proper functioning of the brake system is paramount for the safety of vehicles of all kinds. The back plate and the friction lining of brake pads must meet the highest quality standards to guarantee the functionality of the pads in their system. Visual 3D inspection with the structured-light projector Pulsar from SAC enables you to check brake pads for planarity, parallelism, and thickness. The measurement results in x, y, and z allow for a precise quality assessment of the inspection part.

The “deflection” of the back plate must not exceed a determined tolerance limit in the planarity check so the brake pistons fit flush with the back plate during braking. Furthermore, the heat-resisting coating at the functional surfaces of the back plate is checked for foreign particles and undesired deviations in planarity. Parallelism, planarity, and thickness are checked with a two-digit µm accuracy and evaluated accordingly.

The planarity, parallelism, and thickness measurements are evaluated with our image-processing software Coake® 7 and the integrated virtual coordinate measuring machine (VCMM). The VCMM enables you to exactly position the measurement points at and on the lining according to the predefined requirements.


Fig. 1: Measurement points can be positioned/defined freely


Fig. 2: Scaled height information displayed in color


Fig. 3: Texture image of the lining


Fig. 4: Height image of the lining, measurement resolution (scattering) ± 20 µm

Your benefits at one glance:

  • 100% inline inspection instead of random sampling
  • Complete monitoring of the production process with immediate intervention possibilities to change the production parameters
  • Highest precision: real 3D height information down to the 4/100 µm range
  • Short acquisition time: High inline cycle rates are possible.

The following video shows the practical implementation of our solution:

Other areas of application for Pulsar:

  • 3D inspection of pins and connectors

Further information about our products Pulsar and Coake® 7.