针对待融合的证据体包含基本概率分配值相差较大的非单点证据时,基于pignistic距离的Dempster组合规则适用性评价方法判定结果存在模糊性甚至不准确的问题,提出了一种表示证据体之间关联性的改进pignistic距离,并将改进的pignistic距离与经典冲突系数相结合,提出了对Dempster组合规则适用性评价的新方法。在新方法中,定义了一种新的证据体冲突衡量系数用于判定Dempster规则的适用性。当经典冲突系数为0时,新系数与改进pignistic距离一致;当经典冲突系数不为0时,新系数与改进pignistic距离和经典冲突系数之和的平均值一致。算例分析的结果表明,与基于pignistic距离的Dempster规则适用性评价方法相比,新的基于改进pignistic距离的Dempster组合规则适用性评价方法有较好的适用性和合理性。
Aiming to overcome the problem that fuzzy or even inaccurate results will be concluded when evaluating the applicability of Dempster's combination rule while the bodies of evidence contain some non-singleton evidences which basic probability assignments have larger differences between any two bodies of evidence, a modified pignistic probability distance was proposed to describe the relevance between bodies of evidence. And then, combining the modified pignistic probability distance with the classical conflict coefficient, a new method of evaluating the applicability of Dempster's combination rule was presented. In the proposed method, a new conflict coefficient was defined to measure the conflict between bodies of evidence. The new conflict coefficient was consistent with the modified pignistic probability distance when the classical conflict coefficient was zero, and it was consistent with an average value of the modified pignistic probability distance and the classical conflict coefficient when the classical conflict coefficient was not zero. The results of the numerical analysis examples demonstrate that compared with the evaluating method based on the pignistic probability distance, the proposed method based on the improved pignistic probability distance can provide more applicable and reasonable evaluating results of the applicability of the Dempster's combination rule.