diff -Naur ros-humble-nav2-constrained-smoother-1.1.9_org/include/nav2_constrained_smoother/smoother.hpp ros-humble-nav2-constrained-smoother-1.1.9/include/nav2_constrained_smoother/smoother.hpp
--- ros-humble-nav2-constrained-smoother-1.1.9_org/include/nav2_constrained_smoother/smoother.hpp	2023-09-11 19:06:58.704711382 +0800
+++ ros-humble-nav2-constrained-smoother-1.1.9/include/nav2_constrained_smoother/smoother.hpp	2023-09-11 19:09:44.435139162 +0800
@@ -292,7 +292,7 @@
     }
     int last_i = 0;
     int prelast_i = -1;
-    Eigen::Vector2d prelast_dir;
+    Eigen::Vector2d prelast_dir(0.0, 0.0);
     for (int i = 1; i <= static_cast<int>(path_optim.size()); i++) {
       if (i == static_cast<int>(path_optim.size()) || optimized[i]) {
         if (prelast_i != -1) {