In obstacle position detection

because of sensor error existence

the multisensor fusion are used to reduce the uncertainty so that the estimation result is reliable.A new method based on correction matrix of the least square method multisensor fusion is proposed.A correction matrix is set up by the prior information of IR（infrared ray）sensor.The linear credibility weighted equation are obtained

according to the least square method principle.Simulation and experiment in mobile robot"FutureStar"are done with and without correction matrix

and it shows that the least square method can greatly reduce uncertainty and the estimation with correction matrix is more close to the true value.