| 摘要 |
<p>A suspension to carry a boom on a vehicle such as a tractor and support agricultural spray heads. The suspension includes passive elements to maintain the boom in set relation to the vehicle. The suspension also includes an active part which can act to alter a dimension of the passive suspension. A control circuit for the active part derives information from sensors of the height of the boom above the ground and forces the alteration of the dimension to maintain a substantially uniform and constant height for the boom. The active part operates for lower frequencies than the passive part so that when the vehicle tilts, for example on its suspension on uneven ground, the relation set by the passive part is altered to maintain the desired height while the passive part is still effective at the higher frequencies to stabilise the boom.</p> |
