| 摘要 |
A variable support mechanism includes a plurality of pneumatic bladders (20-30) and an electronic control system for controlling the inflation and deflation thereof. Each of the bladders communicates through a valve (20A-30A) with a common manifold (41). The operations of the valves are individually controlled by a microprocessor (42). A pressure sensor (43) communicates with the manifold and generates electrical signals that are representative of the magnitude of the fluid pressure in the manifold to the microprocessor. The microprocessor is also connected to a vent valve (44) that provides selective fluid communication between the manifold and the atmosphere. The microprocessor is further connected to a pressure valve (45) that provides selective fluid communication between the manifold and a pump (46). Initially, the magnitude of the pressure in each of the bladders is sampled, measured, and stored by the electronic control system. Then, the measured pressure readings from the bladders are compared with a respective target values. The bladders that have been identified as being Too Low or Too High are inflated or deflated respectively. |
