To　better　solve　the　attitude　of　robots　with　high　precision　using　low　cost　inertial　measurement　unit　(IMU),　we　design　novel　calibration　methods,　namely　twelve　positions　calibration　method,　method　based　on　ellipsoid　fitting　and　eight　positions　calibration　method,　to　effectively　calibrate　accelerometer,　magnetometer　and　gyroscope,　respectively.　An　attitude　estimator　using　data　from　the　multi-sensors　calibrated　by　our　proposed　methods　was　designed　based　on　Kalman　Filter,　with　its　estimated　value　of　the　attitude　prediction　deviation　fed　back　to　the　predicted　value　as　the　prediction　deviation　at　the　end　of　each　filtering　period.　Finally,　relevant　experiments　are　designed　to　verify　the　validity　of　the　proposed　attitude　solution　method　as　well　as　the　proposed　calibration　methods,　with　results　showing　that　the　roll　and　pitch　angle　measured　by　the　attitude　measurement　unit　have　an　effective　resolution　of　0.1　degrees　and　the　yaw　angle　has　an　effective　resolution　of　1　degrees.　The　innovation　of　this　paper　is　that　the　proposed　calibration　methods　can　be　carried　out　with　simple　tools,　eliminating　the　need　for　expensive　and　complicated　multi-axis　turntables,　and　the　designed　attitude　measurement　unit　based　on　calibrated　low　cost　IMU＇s　inertial　sensors　has　smaller　size,　higher　resolution　in　roll　and　pitch,　and　much　lower　cost　compared　with　the　commercial　MTi-G-710.　The　accuracy　of　the　attitude　solution　for　such　IMU　is　high　enough　for　the　application　on　robots.