diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index 1f0b1e62c1..666499c440 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -376,6 +376,48 @@ const AP_Param::GroupInfo AP_InertialSensor::var_info[] = {
     // @User: Advanced
     AP_GROUPINFO("POS3", 29, AP_InertialSensor, _accel_pos[2], 0.0f),
 
+    // @Param: GYR_ID
+    // @DisplayName: Gyro ID
+    // @Description: Gyro sensor ID, taking into account its type, bus and instance
+    // @ReadOnly: True
+    // @User: Advanced
+    AP_GROUPINFO("GYR_ID", 30, AP_InertialSensor, _gyro_id[0], 0),
+
+    // @Param: GYR2_ID
+    // @DisplayName: Gyro2 ID
+    // @Description: Gyro2 sensor ID, taking into account its type, bus and instance
+    // @ReadOnly: True
+    // @User: Advanced
+    AP_GROUPINFO("GYR2_ID", 31, AP_InertialSensor, _gyro_id[1], 0),
+
+    // @Param: GYR3_ID
+    // @DisplayName: Gyro3 ID
+    // @Description: Gyro3 sensor ID, taking into account its type, bus and instance
+    // @ReadOnly: True
+    // @User: Advanced
+    AP_GROUPINFO("GYR3_ID", 32, AP_InertialSensor, _gyro_id[2], 0),
+
+    // @Param: ACC_ID
+    // @DisplayName: Accelerometer ID
+    // @Description: Accelerometer sensor ID, taking into account its type, bus and instance
+    // @ReadOnly: True
+    // @User: Advanced
+    AP_GROUPINFO("ACC_ID", 33, AP_InertialSensor, _accel_id[0], 0),
+
+    // @Param: ACC2_ID
+    // @DisplayName: Accelerometer2 ID
+    // @Description: Accelerometer2 sensor ID, taking into account its type, bus and instance
+    // @ReadOnly: True
+    // @User: Advanced
+    AP_GROUPINFO("ACC2_ID", 34, AP_InertialSensor, _accel_id[1], 0),
+
+    // @Param: ACC3_ID
+    // @DisplayName: Accelerometer3 ID
+    // @Description: Accelerometer3 sensor ID, taking into account its type, bus and instance
+    // @ReadOnly: True
+    // @User: Advanced
+    AP_GROUPINFO("ACC3_ID", 35, AP_InertialSensor, _accel_id[2], 0),
+
     /*
       NOTE: parameter indexes have gaps above. When adding new
       parameters check for conflicts carefully
@@ -457,24 +499,67 @@ AP_InertialSensor *AP_InertialSensor::get_instance()
 /*
   register a new gyro instance
  */
-uint8_t AP_InertialSensor::register_gyro(uint16_t raw_sample_rate_hz)
+uint8_t AP_InertialSensor::register_gyro(uint16_t raw_sample_rate_hz,
+                                         uint32_t id)
 {
     if (_gyro_count == INS_MAX_INSTANCES) {
         AP_HAL::panic("Too many gyros");
     }
+
     _gyro_raw_sample_rates[_gyro_count] = raw_sample_rate_hz;
+
+    bool saved = _gyro_id[_gyro_count].load();
+
+    if (saved && (uint32_t)_gyro_id[_gyro_count] != id) {
+        // inconsistent gyro id - mark it as needing calibration
+        _gyro_cal_ok[_gyro_count] = false;
+    }
+
+    _gyro_id[_gyro_count].set((int32_t) id);
+
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4 || CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN || CONFIG_HAL_BOARD == HAL_BOARD_SITL
+    if (!saved) {
+        // assume this is the same sensor and save its ID to allow seamless
+        // transition from when we didn't have the IDs.
+        _gyro_id[_gyro_count].save();
+    }
+#endif
+
     return _gyro_count++;
 }
 
 /*
   register a new accel instance
  */
-uint8_t AP_InertialSensor::register_accel(uint16_t raw_sample_rate_hz)
+uint8_t AP_InertialSensor::register_accel(uint16_t raw_sample_rate_hz,
+                                          uint32_t id)
 {
     if (_accel_count == INS_MAX_INSTANCES) {
         AP_HAL::panic("Too many accels");
     }
+
     _accel_raw_sample_rates[_accel_count] = raw_sample_rate_hz;
+    bool saved = _accel_id[_accel_count].load();
+
+    if (!saved) {
+        // inconsistent accel id
+        _accel_id_ok[_accel_count] = false;
+    } else if ((uint32_t)_accel_id[_accel_count] != id) {
+        // inconsistent accel id
+        _accel_id_ok[_accel_count] = false;
+    } else {
+        _accel_id_ok[_accel_count] = true;
+    }
+
+    _accel_id[_accel_count].set((int32_t) id);
+
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4 || CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN || CONFIG_HAL_BOARD == HAL_BOARD_SITL
+        // assume this is the same sensor and save its ID to allow seamless
+        // transition from when we didn't have the IDs.
+        _accel_id_ok[_accel_count] = true;
+        _accel_id[_accel_count].save();
+#endif
+
     return _accel_count++;
 }
 
@@ -805,6 +890,9 @@ bool AP_InertialSensor::accel_calibrated_ok_all() const
 
     // check each accelerometer has offsets saved
     for (uint8_t i=0; i<get_accel_count(); i++) {
+        if (!_accel_id_ok[i]) {
+            return false;
+        }
         // exactly 0.0 offset is extremely unlikely
         if (_accel_offset[i].get().is_zero()) {
             return false;
@@ -990,6 +1078,7 @@ void AP_InertialSensor::_save_gyro_calibration()
 {
     for (uint8_t i=0; i<INS_MAX_INSTANCES; i++) {
         _gyro_offset[i].save();
+        _gyro_id[i].save();
     }
 }
 
@@ -1443,6 +1532,8 @@ void AP_InertialSensor::_acal_save_calibrations()
             _accel_calibrator[i].get_calibration(bias, gain);
             _accel_offset[i].set_and_save(bias);
             _accel_scale[i].set_and_save(gain);
+            _accel_id[i].save();
+            _accel_id_ok[i] = true;
         } else {
             _accel_offset[i].set_and_save(Vector3f(0,0,0));
             _accel_scale[i].set_and_save(Vector3f(0,0,0));
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.h b/libraries/AP_InertialSensor/AP_InertialSensor.h
index 62e995869c..f3010cc9b4 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.h
@@ -66,8 +66,8 @@ public:
 
     /// Register a new gyro/accel driver, allocating an instance
     /// number
-    uint8_t register_gyro(uint16_t raw_sample_rate_hz);
-    uint8_t register_accel(uint16_t raw_sample_rate_hz);
+    uint8_t register_gyro(uint16_t raw_sample_rate_hz, uint32_t id);
+    uint8_t register_accel(uint16_t raw_sample_rate_hz, uint32_t id);
 
     bool calibrate_trim(float &trim_roll, float &trim_pitch);
 
@@ -321,6 +321,11 @@ private:
     // product id
     AP_Int16 _old_product_id;
 
+    // IDs to uniquely identify each sensor: shall remain
+    // the same across reboots
+    AP_Int32 _accel_id[INS_MAX_INSTANCES];
+    AP_Int32 _gyro_id[INS_MAX_INSTANCES];
+
     // accelerometer scaling and offsets
     AP_Vector3f _accel_scale[INS_MAX_INSTANCES];
     AP_Vector3f _accel_offset[INS_MAX_INSTANCES];
@@ -354,8 +359,9 @@ private:
     enum Rotation _gyro_orientation[INS_MAX_INSTANCES];
     enum Rotation _accel_orientation[INS_MAX_INSTANCES];
 
-    // calibrated_ok flags
+    // calibrated_ok/id_ok flags
     bool _gyro_cal_ok[INS_MAX_INSTANCES];
+    bool _accel_id_ok[INS_MAX_INSTANCES];
 
     // primary accel and gyro
     uint8_t _primary_gyro;
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_BMI160.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_BMI160.cpp
index 7faab178bb..bf95a98cce 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_BMI160.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_BMI160.cpp
@@ -177,8 +177,10 @@ void AP_InertialSensor_BMI160::start()
 
     _dev->get_semaphore()->give();
 
-    _accel_instance = _imu.register_accel(BMI160_ODR_TO_HZ(BMI160_ODR));
-    _gyro_instance = _imu.register_gyro(BMI160_ODR_TO_HZ(BMI160_ODR));
+    _accel_instance = _imu.register_accel(BMI160_ODR_TO_HZ(BMI160_ODR),
+                                          _dev->get_id());
+    _gyro_instance = _imu.register_gyro(BMI160_ODR_TO_HZ(BMI160_ODR),
+                                        _dev->get_id());
 
     /* Call _poll_data() at 1kHz */
     _dev->register_periodic_callback(1000,
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
index f178fddaa2..8b6477c7bf 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_HIL.cpp
@@ -27,8 +27,8 @@ AP_InertialSensor_Backend *AP_InertialSensor_HIL::detect(AP_InertialSensor &_imu
 bool AP_InertialSensor_HIL::_init_sensor(void) 
 {
     // grab the used instances
-    _imu.register_gyro(1200);
-    _imu.register_accel(1200);
+    _imu.register_gyro(1200, 1);
+    _imu.register_accel(1200, 1);
 
     _imu.set_hil_mode();
 
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_L3G4200D.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_L3G4200D.cpp
index e9bde0553a..4a1833ea7f 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_L3G4200D.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_L3G4200D.cpp
@@ -206,8 +206,8 @@ bool AP_InertialSensor_L3G4200D::_init_sensor(void)
  */
 void AP_InertialSensor_L3G4200D::start(void)
 {
-    _gyro_instance = _imu.register_gyro(800);
-    _accel_instance = _imu.register_accel(800);
+    _gyro_instance = _imu.register_gyro(800, _dev->get_id());
+    _accel_instance = _imu.register_accel(800, _dev->get_id());
 
     // start the timer process to read samples
     _dev->register_periodic_callback(1250, FUNCTOR_BIND_MEMBER(&AP_InertialSensor_L3G4200D::_accumulate, bool));
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_LSM9DS0.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_LSM9DS0.cpp
index 347e2f4744..e01aad67a1 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_LSM9DS0.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_LSM9DS0.cpp
@@ -505,8 +505,8 @@ fail_whoami:
  */
 void AP_InertialSensor_LSM9DS0::start(void)
 {
-    _gyro_instance = _imu.register_gyro(760);
-    _accel_instance = _imu.register_accel(800);
+    _gyro_instance = _imu.register_gyro(760, _dev_gyro->get_id());
+    _accel_instance = _imu.register_accel(800, _dev_accel->get_id());
 
     set_gyro_orientation(_gyro_instance, _rotation);
     set_accel_orientation(_accel_instance, _rotation);
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
index 94a39df5cb..96b7b31403 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.cpp
@@ -382,8 +382,8 @@ void AP_InertialSensor_MPU6000::start()
     _dev->get_semaphore()->give();
 
     // grab the used instances
-    _gyro_instance = _imu.register_gyro(1000);
-    _accel_instance = _imu.register_accel(1000);
+    _gyro_instance = _imu.register_gyro(1000, _dev->get_id());
+    _accel_instance = _imu.register_accel(1000, _dev->get_id());
 
     // setup sensor rotations from probe()
     set_gyro_orientation(_gyro_instance, _rotation);
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_MPU9250.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_MPU9250.cpp
index 927424fd84..9535524636 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_MPU9250.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_MPU9250.cpp
@@ -320,8 +320,8 @@ void AP_InertialSensor_MPU9250::start()
     _dev->get_semaphore()->give();
 
     // grab the used instances
-    _gyro_instance = _imu.register_gyro(DEFAULT_SAMPLE_RATE);
-    _accel_instance = _imu.register_accel(DEFAULT_SAMPLE_RATE);
+    _gyro_instance = _imu.register_gyro(DEFAULT_SAMPLE_RATE, _dev->get_id());
+    _accel_instance = _imu.register_accel(DEFAULT_SAMPLE_RATE, _dev->get_id());
 
     // start the timer process to read samples
     _dev->register_periodic_callback(1000, FUNCTOR_BIND_MEMBER(&AP_InertialSensor_MPU9250::_read_sample, bool));
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_PX4.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_PX4.cpp
index 61b886a72e..7a4fc704d6 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_PX4.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_PX4.cpp
@@ -112,7 +112,7 @@ bool AP_InertialSensor_PX4::_init_sensor(void)
         if (samplerate < 100 || samplerate > 10000) {
             AP_HAL::panic("Invalid gyro sample rate");
         }
-        _gyro_instance[i] = _imu.register_gyro(samplerate);
+        _gyro_instance[i] = _imu.register_gyro(samplerate, i);
         _gyro_sample_time[i] = 1.0f / samplerate;
     }
 
@@ -152,7 +152,7 @@ bool AP_InertialSensor_PX4::_init_sensor(void)
         if (samplerate < 100 || samplerate > 10000) {
             AP_HAL::panic("Invalid accel sample rate");
         }
-        _accel_instance[i] = _imu.register_accel(samplerate);
+        _accel_instance[i] = _imu.register_accel(samplerate, i);
         _accel_sample_time[i] = 1.0f / samplerate;
     }
 
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_QURT.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_QURT.cpp
index f528c131b2..4783aab534 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_QURT.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_QURT.cpp
@@ -28,10 +28,10 @@ AP_InertialSensor_Backend *AP_InertialSensor_QURT::detect(AP_InertialSensor &_im
     return sensor;
 }
 
-bool AP_InertialSensor_QURT::init_sensor(void) 
+bool AP_InertialSensor_QURT::init_sensor(void)
 {
-    gyro_instance = _imu.register_gyro(1000);
-    accel_instance = _imu.register_accel(1000);
+    gyro_instance = _imu.register_gyro(1000, 1);
+    accel_instance = _imu.register_accel(1000, 1);
 
     mpu9250_mag_buffer = new ObjectBuffer<mpu9x50_data>(20);
     init_mpu9250();
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_SITL.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_SITL.cpp
index f4c12610a1..0dc4555cb4 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_SITL.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_SITL.cpp
@@ -36,8 +36,8 @@ bool AP_InertialSensor_SITL::init_sensor(void)
 
     // grab the used instances
     for (uint8_t i=0; i<INS_SITL_INSTANCES; i++) {
-        gyro_instance[i] = _imu.register_gyro(sitl->update_rate_hz);
-        accel_instance[i] = _imu.register_accel(sitl->update_rate_hz);
+        gyro_instance[i] = _imu.register_gyro(sitl->update_rate_hz, i);
+        accel_instance[i] = _imu.register_accel(sitl->update_rate_hz, i);
     }
 
     hal.scheduler->register_timer_process(FUNCTOR_BIND_MEMBER(&AP_InertialSensor_SITL::timer_update, void));
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_qflight.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_qflight.cpp
index 138586a184..30d785aae5 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_qflight.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_qflight.cpp
@@ -31,8 +31,8 @@ AP_InertialSensor_Backend *AP_InertialSensor_QFLIGHT::detect(AP_InertialSensor &
 
 bool AP_InertialSensor_QFLIGHT::init_sensor(void) 
 {
-    gyro_instance = _imu.register_gyro(1000);
-    accel_instance = _imu.register_accel(1000);
+    gyro_instance = _imu.register_gyro(1000, 1);
+    accel_instance = _imu.register_accel(1000, 1);
 
     hal.scheduler->register_timer_process(FUNCTOR_BIND_MEMBER(&AP_InertialSensor_QFLIGHT::timer_update, void));
     return true;