From 53baa3287aef029bd089d437fdad621df3f4d6d1 Mon Sep 17 00:00:00 2001
From: Iori Kumagai <iori-kumagai@aist.go.jp>
Date: Wed, 4 Feb 2026 17:50:45 +0900
Subject: [PATCH 1/2] [DdpCentroidal] Preserve latest returned value from
 ddp_solver_ to check whether ddp_solver_->solve() is successfully solved

---
 include/CCC/DdpCentroidal.h | 3 +++
 src/DdpCentroidal.cpp       | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/CCC/DdpCentroidal.h b/include/CCC/DdpCentroidal.h
index 8375a65..71c4bf4 100644
--- a/include/CCC/DdpCentroidal.h
+++ b/include/CCC/DdpCentroidal.h
@@ -362,5 +362,8 @@ class DdpCentroidal
 
   //! Force scale limits (i.e., limits of \f$\lambda_i\f$ in the order of lower, upper)
   std::array<double, 2> force_scale_limits_ = {0.0, 1e6};
+
+  //! Latest returned value from DDP solver
+  bool ddp_solved_ = false;
 };
 } // namespace CCC
diff --git a/src/DdpCentroidal.cpp b/src/DdpCentroidal.cpp
index e09b242..404c703 100644
--- a/src/DdpCentroidal.cpp
+++ b/src/DdpCentroidal.cpp
@@ -226,11 +226,11 @@ Eigen::VectorXd DdpCentroidal::planOnce(const std::function<MotionParam(double)>
       double t = current_time + i * ddp_problem_->dt();
       current_u_list.push_back(DdpProblem::InputDimVector::Zero(ddp_problem_->inputDim(t)));
     }
-    ddp_solver_->solve(current_time, initial_param.toState(ddp_problem_->mass_), current_u_list);
+    ddp_solved_ = ddp_solver_->solve(current_time, initial_param.toState(ddp_problem_->mass_), current_u_list);
   }
   else
   {
-    ddp_solver_->solve(current_time, initial_param.toState(ddp_problem_->mass_), initial_param.u_list);
+    ddp_solved_ = ddp_solver_->solve(current_time, initial_param.toState(ddp_problem_->mass_), initial_param.u_list);
   }
 
   return ddp_solver_->controlData().u_list[0];

From 841783133a5415d610a6ceb616431ee41c4ba8ed Mon Sep 17 00:00:00 2001
From: Iori Kumagai <iori-kumagai@aist.go.jp>
Date: Fri, 6 Mar 2026 17:46:32 +0900
Subject: [PATCH 2/2] add ddp_solved_ flag to DdpZmp and DdpSingleRigidBody

---
 include/CCC/DdpSingleRigidBody.h | 3 +++
 include/CCC/DdpZmp.h             | 3 +++
 src/DdpSingleRigidBody.cpp       | 4 ++--
 src/DdpZmp.cpp                   | 8 ++++----
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/include/CCC/DdpSingleRigidBody.h b/include/CCC/DdpSingleRigidBody.h
index 86e9eac..5618665 100644
--- a/include/CCC/DdpSingleRigidBody.h
+++ b/include/CCC/DdpSingleRigidBody.h
@@ -402,5 +402,8 @@ class DdpSingleRigidBody
 
   //! Force scale limits (i.e., limits of \f$\lambda_i\f$ in the order of lower, upper)
   std::array<double, 2> force_scale_limits_ = {0.0, 1e6};
+
+  //! Latest returned value from DDP solver
+  bool ddp_solved_ = false;
 };
 } // namespace CCC
diff --git a/include/CCC/DdpZmp.h b/include/CCC/DdpZmp.h
index 71bab6f..c6b5a93 100644
--- a/include/CCC/DdpZmp.h
+++ b/include/CCC/DdpZmp.h
@@ -297,5 +297,8 @@ class DdpZmp
 
   //! DDP solver
   std::shared_ptr<nmpc_ddp::DDPSolver<6, 3>> ddp_solver_;
+
+  //! Latest returned value from DDP solver
+  bool ddp_solved_ = false;
 };
 } // namespace CCC
diff --git a/src/DdpSingleRigidBody.cpp b/src/DdpSingleRigidBody.cpp
index c09a9c3..e44ec2b 100644
--- a/src/DdpSingleRigidBody.cpp
+++ b/src/DdpSingleRigidBody.cpp
@@ -296,11 +296,11 @@ Eigen::VectorXd DdpSingleRigidBody::planOnce(const std::function<MotionParam(dou
       double t = current_time + i * ddp_problem_->dt();
       current_u_list.push_back(DdpProblem::InputDimVector::Zero(ddp_problem_->inputDim(t)));
     }
-    ddp_solver_->solve(current_time, initial_param.toState(), current_u_list);
+    ddp_solved_ = ddp_solver_->solve(current_time, initial_param.toState(), current_u_list);
   }
   else
   {
-    ddp_solver_->solve(current_time, initial_param.toState(), initial_param.u_list);
+    ddp_solved_ = ddp_solver_->solve(current_time, initial_param.toState(), initial_param.u_list);
   }
 
   return ddp_solver_->controlData().u_list[0];
diff --git a/src/DdpZmp.cpp b/src/DdpZmp.cpp
index ef361f9..c791966 100644
--- a/src/DdpZmp.cpp
+++ b/src/DdpZmp.cpp
@@ -157,13 +157,13 @@ DdpZmp::PlannedData DdpZmp::planOnce(const std::function<RefData(double)> & ref_
 
   if(initial_param.u_list.empty())
   {
-    ddp_solver_->solve(current_time, initial_param.toState(),
-                       std::vector<DdpProblem::InputDimVector>(ddp_solver_->config().horizon_steps,
-                                                               DdpProblem::InputDimVector::Zero()));
+    ddp_solved_ = ddp_solver_->solve(current_time, initial_param.toState(),
+                                     std::vector<DdpProblem::InputDimVector>(ddp_solver_->config().horizon_steps,
+                                                                             DdpProblem::InputDimVector::Zero()));
   }
   else
   {
-    ddp_solver_->solve(current_time, initial_param.toState(), initial_param.u_list);
+    ddp_solved_ = ddp_solver_->solve(current_time, initial_param.toState(), initial_param.u_list);
   }
 
   PlannedData planned_data;