A gyro is read too slowly for the main loop rate

What ArduPilot says:

• Gyro N rate NHz < loop ratex1.8 NHz
• Gyro N rate NHz < loop rate*1.8 NHz

An IMU has to deliver gyro samples at least 1.8 times as fast as the main loop runs (SCHED_LOOP_RATE). The message gives the gyro (counting from 0), the rate it really delivers and the rate needed. With a slower gyro the attitude controller would be fed the same sample twice.

What to do, most likely first

1. SCHED_LOOP_RATE was raised above what this IMU can keep up with.

   CheckDivide the last number in the message by 1.8: that is your loop rate. Compare the middle number with it.

   FixSet SCHED_LOOP_RATE back to the vehicle's default and reboot.

2. The IMU can run faster, but fast sampling is not switched on for it.

   CheckINS_FAST_SAMPLE has no bit for that IMU, or INS_GYRO_RATE is 0 (1 kHz).

   FixSet the IMU's bit in INS_FAST_SAMPLE and raise INS_GYRO_RATE one step, then reboot. This costs processor time: on a small board lower the loop rate instead.

Parameters to look at

Where to do it:Parameter Compare & Migrate