diff --git a/PlaneGcsSdk.Contract_Shared/Copters/FlightCommand.cs b/PlaneGcsSdk.Contract_Shared/Copters/FlightCommand.cs
index f6f5887..f7689bf 100644
--- a/PlaneGcsSdk.Contract_Shared/Copters/FlightCommand.cs
+++ b/PlaneGcsSdk.Contract_Shared/Copters/FlightCommand.cs
@@ -35,6 +35,11 @@
         /// </summary>
         TakeOff = 22,
 
+        /// <summary>
+        /// 命令飞行器改变速度
+        /// </summary>
+        ChangeSpeed = 178,
+
         /// <summary>
         /// 命令LED颜色改变
         /// </summary>
diff --git a/PlaneGcsSdk_Private_NET46/PlaneGcsSdk_Private_NET46.csproj b/PlaneGcsSdk_Private_NET46/PlaneGcsSdk_Private_NET46.csproj
index 4625ca5..0569a3e 100644
--- a/PlaneGcsSdk_Private_NET46/PlaneGcsSdk_Private_NET46.csproj
+++ b/PlaneGcsSdk_Private_NET46/PlaneGcsSdk_Private_NET46.csproj
@@ -57,6 +57,10 @@
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\..\Plane.Libraries\Plane.Windows.Messages\Plane.Windows.Messages.csproj">
+      <Project>{413C18E2-235F-4E15-B5C1-633657DE5D7A}</Project>
+      <Name>Plane.Windows.Messages</Name>
+    </ProjectReference>
     <ProjectReference Include="..\PlaneGcsSdk.Contract_Private\PlaneGcsSdk.Contract_Private.csproj">
       <Project>{47141894-ece3-48ca-8dcf-ca751bda231e}</Project>
       <Name>PlaneGcsSdk.Contract_Private</Name>
diff --git a/PlaneGcsSdk_Shared/Communication/TcpConnection.cs b/PlaneGcsSdk_Shared/Communication/TcpConnection.cs
index 1879629..58c086f 100644
--- a/PlaneGcsSdk_Shared/Communication/TcpConnection.cs
+++ b/PlaneGcsSdk_Shared/Communication/TcpConnection.cs
@@ -44,6 +44,7 @@ namespace Plane.Communication
                 }
                 _isBroken = false;
             }
+            
             _stream = _client.GetStream();
         }
 
diff --git a/PlaneGcsSdk_Shared/Communication/TcpConnectionBase.cs b/PlaneGcsSdk_Shared/Communication/TcpConnectionBase.cs
index 208443a..c1e7231 100644
--- a/PlaneGcsSdk_Shared/Communication/TcpConnectionBase.cs
+++ b/PlaneGcsSdk_Shared/Communication/TcpConnectionBase.cs
@@ -24,7 +24,10 @@ namespace Plane.Communication
             {
                 try
                 {
-                    return _client.Available;
+                    if (_client.Connected)
+                        return _client.Available;
+                    else
+                        return 0;
                 }
                 catch (ObjectDisposedException ex)
                 {
@@ -89,6 +92,7 @@ namespace Plane.Communication
             {
                 while (Available < count)
                 {
+                    if (!IsOpen) return 0;
                     await Task.Delay(5).ConfigureAwait(false);
                 }
                 return await _stream.ReadAsync(buffer, offset, count);
diff --git a/PlaneGcsSdk_Shared/Copters/Mission.cs b/PlaneGcsSdk_Shared/Copters/Mission.cs
index da36bb8..5d5a8f8 100644
--- a/PlaneGcsSdk_Shared/Copters/Mission.cs
+++ b/PlaneGcsSdk_Shared/Copters/Mission.cs
@@ -198,5 +198,13 @@ namespace Plane.Copters
             G = green,          //Green
             B = blue            //Blue
         };
+
+        public static IMission CreateChangeSpeedMission(float levelSpeed, float upSpeed, float downSpeed) => new Mission
+        {
+            Command = FlightCommand.ChangeSpeed,
+            Param1 = levelSpeed,    //水平速度
+            Param2 = upSpeed,       //上升速度
+            Param3 = downSpeed,     //下降速度
+        };
     }
 }
diff --git a/PlaneGcsSdk_Shared/PlaneGcsSdk_Shared.projitems b/PlaneGcsSdk_Shared/PlaneGcsSdk_Shared.projitems
index c18897f..eb29cd0 100644
--- a/PlaneGcsSdk_Shared/PlaneGcsSdk_Shared.projitems
+++ b/PlaneGcsSdk_Shared/PlaneGcsSdk_Shared.projitems
@@ -10,6 +10,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)CommunicationManagement\CommModule.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)CommunicationManagement\CommModulePacketAnalysis.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Communication\ExceptionThrownEventSource.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Communication\EmptyConnection.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)Communication\CompositeConnection.cs" />