AC_PrecLand: Fix some typos

Fixed some typos found in the code.

libraries/AC_PrecLand/AC_PrecLand.cpp

@@ -150,7 +150,7 @@ const AP_Param::GroupInfo AC_PrecLand::var_info[] = {
 
     // @Param: TIMEOUT
     // @DisplayName: PrecLand retry timeout
-    // @Description: Time for which vehicle continues descend even if target is lost. After this time period, vehicle will attemp a landing retry depending on PLND_STRICT parameter.
+    // @Description: Time for which vehicle continues descend even if target is lost. After this time period, vehicle will attempt a landing retry depending on PLND_STRICT parameter.
     // @Range: 0 20
     // @Units: s
     AP_GROUPINFO("TIMEOUT", 13, AC_PrecLand, _retry_timeout_sec, 4),
@@ -400,7 +400,7 @@ bool AC_PrecLand::target_acquired()
 {
     if ((AP_HAL::millis()-_last_update_ms) > LANDING_TARGET_TIMEOUT_MS) {
         if (_target_acquired) {
-            // just lost the landing target, inform the user. This message will only be sent once everytime target is lost
+            // just lost the landing target, inform the user. This message will only be sent once every time target is lost
             gcs().send_text(MAV_SEVERITY_CRITICAL, "PrecLand: Target Lost");
         }
         // not had a sensor update since a long time
@@ -622,7 +622,7 @@ bool AC_PrecLand::retrieve_los_meas(Vector3f& target_vec_unit_body)
         }
 
 
-        // rotate vector based on sensor oriention to get correct body frame vector
+        // rotate vector based on sensor orientation to get correct body frame vector
         if (_orient != ROTATION_PITCH_270) {
             // by default, the vector is constructed downwards in body frame
             // hence, we do not do any rotation if the orientation is downwards

libraries/AC_PrecLand/AC_PrecLand.h

@@ -188,7 +188,7 @@ private:
     AP_Float                    _xy_max_dist_desc;  // Vehicle doing prec land will only descent vertically when horizontal error (in m) is below this limit
     AP_Int8                     _strict;            // PrecLand strictness
     AP_Int8                     _retry_max;         // PrecLand Maximum number of retires to a failed landing
-    AP_Float                    _retry_timeout_sec; // Time for which vehicle continues descend even if target is lost. After this time period, vehicle will attemp a landing retry depending on PLND_STRICT param.
+    AP_Float                    _retry_timeout_sec; // Time for which vehicle continues descend even if target is lost. After this time period, vehicle will attempt a landing retry depending on PLND_STRICT param.
     AP_Int8                     _retry_behave;      // Action to do when trying a landing retry
     AP_Float                    _sensor_min_alt;     // PrecLand minimum height required for detecting target
     AP_Float                    _sensor_max_alt;     // PrecLand maximum height the sensor can detect target

libraries/AC_PrecLand/AC_PrecLand_StateMachine.cpp

@@ -7,11 +7,11 @@
 #include <AP_AHRS/AP_AHRS.h>
 #include <GCS_MAVLink/GCS.h>
 
-static const float MAX_POS_ERROR_M = 0.75f;  // Maximum possition error for retry locations
+static const float MAX_POS_ERROR_M = 0.75f;  // Maximum position error for retry locations
 static const uint32_t FAILSAFE_INIT_TIMEOUT_MS = 7000;   // Timeout in ms before failsafe measures are started. During this period vehicle is completely stopped to give user the time to take over
 static const float RETRY_OFFSET_ALT_M = 1.5f;  // This gets added to the altitude of the retry location
 
-// Initialize the state machine. This is called everytime vehicle switches mode
+// Initialize the state machine. This is called every time vehicle switches mode
 void AC_PrecLand_StateMachine::init()
 {
     AC_PrecLand *_precland = AP::ac_precland();
@@ -24,14 +24,14 @@ void AC_PrecLand_StateMachine::init()
         // precland is not enabled, prec land state machine methods should not be called!
         return;
     }
-    // init is only called ONCE per mode change. So in a particuar mode we can retry only a finite times.
+    // init is only called ONCE per mode change. So in a particular mode we can retry only a finite times.
     // The counter will be reset if the statemachine is called from a different mode
     _retry_count = 0;
     // reset every other statemachine
     reset_failed_landing_statemachine();
 }
 
-// Reset the landing statemachines. This needs to be called everytime the landing target is back in sight.
+// Reset the landing statemachines. This needs to be called every time the landing target is back in sight.
 // So that if the landing target goes out of sight again, we can start the failed landing procedure back from the beginning stage
 void AC_PrecLand_StateMachine::reset_failed_landing_statemachine()
 {

libraries/AC_PrecLand/AC_PrecLand_StateMachine.h

@@ -23,7 +23,7 @@ public:
     // Do not allow copies
     CLASS_NO_COPY(AC_PrecLand_StateMachine);
 
-    // Initialize the state machine. This is called everytime vehicle switches mode
+    // Initialize the state machine. This is called every time vehicle switches mode
     void init();
 
     // Current status of the precland state machine
@@ -78,7 +78,7 @@ private:
     // Vector3f "retry_pos_m" is filled with the required location.
     Status retry_landing(Vector3f &retry_pos_m);
 
-    // Reset the landing statemachine. This needs to be called everytime the landing target is back in sight.
+    // Reset the landing statemachine. This needs to be called every time the landing target is back in sight.
     // So that if the landing target goes out of sight again, we can start the failed landing procedure back from the beginning stage
     void reset_failed_landing_statemachine();