【求助】这个优化结果怎么理解？

[gy022]

我用fmincon做一个多变量约束优化：
代码如下，NonLinF为目标函数，NonLinCon为约束方程
function FrictionDriving
x0=[(80/180)*pi,0.004,0.046,0.003,0.0015];
lb=[(80/180)*pi,0.004,0.046,0.002,0.001];
ub=[(120/180)*pi,0.007,0.06,0.005,0.003];
options=optimset('LargeScale','off');
[x,f]=fmincon(@NonLinF,x0,[0 0 0 -1 1;0 0 6 0 0],[0;0.371],[],[],lb,ub,@NonLinCon,options)

结果：
"Optimization terminated: no feasible solution found. Magnitude of search
direction less than 2*options.TolX but constraints are not satisfied."
x =
1.3963 0.0040 0.0460 0.0030 0.0015

f =
1.6086e+004

有几个问题，1. 结果提示中“Magnitude of search direction less than 2*options.TolX”是什么意思？
2. 为什么优化结果中，设计变量x的值即为初始值x0？