： Based on “primary－backup technique” of multiprocessor real－time systems，a rotational scheduling algorithm is presented to provide fault－tolerance in this paper．Simulation results show that the algorithm can not only achieve quite equilibrium of tasks distributing，but also improve utilization ratio of CPUs

In this paper,an imprecise computation-rotational scheduling algorithm for the tasks in multiprocessor real-time system which have timing and fault-tolerant constraints is researched,by which,in the presence of hardware component failures in hard real-time system,tasks still can be executed in their deadline,and the system cannot have disastrous results.

As NDRR fails to provide latency bound when real-time queue is under bursty traffic,a new scheduling discipline named Auto-adaptive Weight Nested DRR(AWNDRR)is presented,which allocates more quanta to real-time queue as its length exceeds a fixed value.

According to the shortages of Scheduler,an improved round-robin scheduling strategy based on deadline is proposed,and it is validated on the micaZ platform.

A mathematical model for ferry schedule problem is developed and solved with simulated annealing algorithm.