Patent attributes
A method and apparatus for assessing the tread on a vehicle tyre, measuring tyre pressure and calculating other parameters such as vehicle weight. The vehicle is driven in a longitudinal direction so that the tyre passes over a first lateral sensor (6) that extends across the footprint of the tyre, the first sensor comprising an array of individual force sensing elements (11), which provide outputs indicative of tyre pressure at points across the footprint of the tyre. The sensing elements are sampled at intervals as the tyre moves over them, so as to build up data relating to the entire footprint of the tyre. The sensing elements are of relatively high resolution to detect areas within the tyre footprint where there is tread cut into the tyre, so that the extent of tread coverage can be assessed. Tyre pressure is also determined. The tyre then passes over a series of second lateral sensors (7) spaced at intervals to assess the tyre around its circumference. The second lateral sensors may be of low resolution, with outputs being compared with each other and with a low resolution sensor (T) adjacent the high resolution sensor to assess whether there is a difference in tyre tread quality at different positions around the tyre circumference. At least one lateral sensor may be provided with resilient portions that extend into tyre tread portions. These will engage the base of a tread portion that is below a predetermined minimum tread depth, so as to increase the area of contact and provide an indication of insufficient tread depth.
