Add: parachute timeout parameter

ArduCopter/crash_check.cpp

@@ -1,7 +1,13 @@
 #include "Copter.h"
 
 // Code to detect a crash main ArduCopter code
-#define CRASH_CHECK_TRIGGER_SEC         2       // 2 seconds inverted indicates a crash
+#if PARACHUTE == ENABLED
+    // CRASH_CHECK_TRIGGER_SEC should be grater than CHUTE_TIMEOUT, to prevent disarming without deploying parachute
+    #define CRASH_CHECK_TRIGGER_SEC (parachute.get_chute_timeout() + 1.0)
+#else
+    #define CRASH_CHECK_TRIGGER_SEC         2       // 2 seconds inverted indicates a crash
+#endif
+
 #define CRASH_CHECK_ANGLE_DEVIATION_DEG 30.0f   // 30 degrees beyond target angle is signal we are out of control
 #define CRASH_CHECK_ANGLE_MIN_DEG       15.0f   // vehicle must be leaning at least 15deg to trigger crash check
 #define CRASH_CHECK_SPEED_MAX           10.0f   // vehicle must be moving at less than 10m/s to trigger crash check
@@ -86,7 +92,7 @@ void Copter::crash_check()
     // we may be crashing
     crash_counter++;
 
-    // check if crashing for 2 seconds
+    // check if crashing for time defined by CRASH_CHECK_TRIGGER_SEC seconds
     if (crash_counter >= (CRASH_CHECK_TRIGGER_SEC * scheduler.get_loop_rate_hz())) {
         LOGGER_WRITE_ERROR(LogErrorSubsystem::CRASH_CHECK, LogErrorCode::CRASH_CHECK_CRASH);
         // send message to gcs
@@ -232,7 +238,6 @@ void Copter::yaw_imbalance_check()
 #if PARACHUTE == ENABLED
 
 // Code to detect a crash main ArduCopter code
-#define PARACHUTE_CHECK_TRIGGER_SEC         1       // 1 second of loss of control triggers the parachute
 #define PARACHUTE_CHECK_ANGLE_DEVIATION_DEG 30.0f   // 30 degrees off from target indicates a loss of control
 
 // parachute_check - disarms motors and triggers the parachute if serious loss of control has been detected
@@ -302,7 +307,7 @@ void Copter::parachute_check()
     }
 
     // increment counter
-    if (control_loss_count < (PARACHUTE_CHECK_TRIGGER_SEC*scheduler.get_loop_rate_hz())) {
+    if (control_loss_count < (parachute.get_chute_timeout()*scheduler.get_loop_rate_hz())) {
         control_loss_count++;
     }
 
@@ -317,8 +322,8 @@ void Copter::parachute_check()
 
     // To-Do: add check that the vehicle is actually falling
 
-    // check if loss of control for at least 1 second
-    } else if (control_loss_count >= (PARACHUTE_CHECK_TRIGGER_SEC*scheduler.get_loop_rate_hz())) {
+    // check if loss of control for at least time defined in CHUTE_TIMEOUT parameter
+    } else if (control_loss_count >= (parachute.get_chute_timeout()*scheduler.get_loop_rate_hz())) {
         // reset control loss counter
         control_loss_count = 0;
         LOGGER_WRITE_ERROR(LogErrorSubsystem::CRASH_CHECK, LogErrorCode::CRASH_CHECK_LOSS_OF_CONTROL);

libraries/AP_Parachute/AP_Parachute.cpp

@@ -83,6 +83,14 @@ const AP_Param::GroupInfo AP_Parachute::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("OPTIONS", 7, AP_Parachute, _options, AP_PARACHUTE_OPTIONS_DEFAULT),
 
+    // @Param: TIMEOUT
+    // @DisplayName: Parachute timeout
+    // @Description: Triggers the parachute if the loss of control lasts for the time specified by this parameter
+    // @Units: s
+    // @Range: 0.5 5.0
+    // @User: Advanced
+    AP_GROUPINFO_FRAME("TIMEOUT", 8, AP_Parachute, _timeout, AP_PARACHUTE_TIMEOUT_DEFAULT, AP_PARAM_FRAME_COPTER),
+
     AP_GROUPEND
 };
 

libraries/AP_Parachute/AP_Parachute.h

@@ -21,6 +21,7 @@
 
 #define AP_PARACHUTE_CRITICAL_SINK_DEFAULT      0      // default critical sink speed in m/s to trigger emergency parachute
 #define AP_PARACHUTE_OPTIONS_DEFAULT            0      // default parachute options: enabled disarm after parachute release
+#define AP_PARACHUTE_TIMEOUT_DEFAULT            1.0f   // default parachute control loss timeout
 
 #ifndef HAL_PARACHUTE_ENABLED
 // default to parachute enabled to match previous configs
@@ -90,6 +91,9 @@ class AP_Parachute {
     // Return the relay index that would be used for param conversion to relay functions
     bool get_legacy_relay_index(int8_t &index) const;
 
+    // Return the CHUTE_TIMEOUT parameter value
+    float get_chute_timeout() const { return _timeout; }
+
     static const struct AP_Param::GroupInfo        var_info[];
 
     // get singleton instance
@@ -105,6 +109,8 @@ class AP_Parachute {
     AP_Int16    _alt_min;       // min altitude the vehicle should have before parachute is released
     AP_Int16    _delay_ms;      // delay before chute release for motors to stop
     AP_Float    _critical_sink;      // critical sink rate to trigger emergency parachute
+    AP_Int32    _options;       // optional behaviour for parachute bitmask
+    AP_Float    _timeout;       // loss of control timeout value in seconds
 
     // internal variables
     uint32_t    _release_time;  // system time that parachute is ordered to be released (actual release will happen 0.5 seconds later)
@@ -118,8 +124,6 @@ class AP_Parachute {
         HoldOpen = (1U<<0),
         SkipDisarmBeforeParachuteRelease = (1U<<1),
     };
-
-    AP_Int32    _options;
 };
 
 namespace AP {