System Formed of Several IMUs

Abstract

The invention relates to a system formed of several IMUs (1, 2, 3, 4, 5) having at least one slave IMU (1, 2, 3, 4) that is configured to record and transmit data. A master IMU (5) having an analysis computing unit is additionally provided which is configured to record data itself and to receive data from the at least one slave IMU (1, 2, 3, 4) and to jointly analyse the data for a calculation of a kinematic chain and to transmit the analysed data to an electronic control device of a machine connected with the system.

Claims

1. System formed of several IMUs (1, 2, 3, 4, 5) having at least one slave IMU (1, 2, 3, 4) which is configured to record and transmit data, characterised by a master IMU (5) having an analysis computing unit which is configured to record data itself and to receive data from the at least one slave IMU (1, 2, 3, 4) and to jointly analyse the data for a calculation of a kinematic chain and to transmit the analysed data to an electronic control device of a machine connected with the system.

2. The system according to claim 1, characterised in that the master IMU has a transmission device that is configured to receive the data from the at least one slave IMU and/or to transmit the analysed data to the electronic control device of the machine.

3. The system according to claim 1, characterised in that the at least one slave IMU (1, 2, 3, 4) has a processing unit which is configured to carry out a pre-processing of the recorded data.

4. The system according to claim 3, characterised in that the master IMU (5) transmits the position data from the at least one slave IMU (1, 2, 3, 4) to this.

5. The system according to claim 1, characterised by at least one angle sensor (6, 7) which determines the angle between two links of the kinematic chain.

6. The system according to claim 5, characterised in that an angle sensor is arranged at an end of the kinematic chain and is formed as a segment sensor.

7. The system according to claim 1, characterised in that several slave IMUs (1, 2, 3, 4) are provided and in that the master IMU is configured to calculate the intermediate angles between the individual slave IMUs (1, 2, 3, 4) and/or between the master IMU (5) and the individual slave IMUs (1, 2, 3, 4) or the absolute angles of the individual IMUs (1, 2, 3, 4, 5) to a reference from the jointly analysed data.

8. The system according to claim 1, characterised in that the IMUs (1, 2, 3, 4, 5) are arranged on a digger (10).

9. The system according to claim 8, characterised in that the master IMU (5) is arranged on the upper carriage (12) of the digger (10).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 shows a schematic oblique view of a digger, which has the system formed of IMUs according to the invention.

[0018] FIG. 2 shows a schematic plan view of a digger from FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0019] In the FIGS. 1 and 2, a digger 10 with an undercarriage 11 and an upper carriage 12 that is arranged rotatably on the undercarriage 11 is shown. A digger arm 13, which here consists of four segments which can be tilted towards each other and towards the upper carriage 12, is arranged on the upper carriage 12. A digger shovel 14 is arranged on the last segment of the digger arm 13 as a tool.

[0020] According to the invention, several IMUs 1, 2, 3, 4, 5 are provided, which are implemented on the upper carriage 12 and on the digger arm 13. A slave IMU 1, 2, 3, 4 is arranged on every segment of the digger arm, which records an acceleration, in particular relative to the Earth's gravity in the X direction, and a rotation rate of the respective segment of the digger arm 13. The slave IMUs 1, 2, 3, 4 have no analysis computing unit, which is configured for the complete analysis of data. However, they can have a less powerful processing unit, with which raw data can be pre-processed. Additionally, the slave IMUs can have a transmission device with which data can be transmitted by a CAN bus. A master IMU 5 which records an acceleration and a rotation rate of the upper carriage 12 is arranged on the upper carriage 12. The slave IMUs 1, 2, 3, 4 are connected with the master IMU 5 via the CAN bus and send the recorded data to the master IMU 5. The data can either be transmitted directly as recorded raw data or can be pre-processed beforehand and then transmitted to the master IMU 5 as pre-processed data, for example as DCM.

[0021] Additionally, an angle sensor 6 is provided on the upper carriage 12, which is arranged in the rotational centre, or is otherwise mechanically connected with the rotational centre and which records the angle relative to the undercarriage 11 in the Y-Z plane perpendicular to the Earth's gravity. The angle sensor 6 is also connected with the master IMU 5 and sends this the angle data. On the connection between the shovel 14 and the digger arm 13, a further angle sensor can be provided instead of the slave IMU 4 or additionally to this, which is preferably formed as a segment sensor 7. The segment sensor 7 measures the angle between the shovel 14 and the last section of the digger arm 13 and is arranged outside of the rotational centre for this. The segment sensor 7 is also connected with the master IMU 5 and sends this the angle data. During operation, strong vibrations and blows occur on the digger shovel 14. The segment sensor 7 is affected less by this in comparison to the slave IMU 4. The master IMU 5 has a transmission device with which the data of the slave IMUs 1, 2, 3, 4 and the angle sensors 6, 7 is received via the CAN bus. Further, the master IMU 5 has an analysis computing unit with which the data of the slave IMUs 1, 2, 3, 4, the recorded data of the master IMU 5 and the data of the angle sensor 6 and, optionally, the data of the segment sensor 7 is jointly analysed. The analysed data is transmitted to a control device (not shown) of the digger 10 by means of the transmission device.

[0022] In FIG. 2, an example is shown of calculating the speed v.sub.2 of the slave IMU 2 on the second segment of the digger arm 13 (referred to as the second IMU 2 in the following) and the speed vs of the master IMU 5 on the upper carriage 12. The digger arm 13 is rotated with and by means of the rotation of the upper carriage 12 with respect to the undercarriage 11. The speeds v.sub.2 and vs are thus tangential to the circular path on which the upper carriage 12 is turning, and they are thus dependent on its angular velocity ω. The master IMU 5 determines the angle of the upper carriage 12 relative to the undercarriage 11 using the additional data of the angle sensor 6. Additionally, the absolute position P.sub.5 of the master IMU 5 in the global coordinate system (only the Y-Z plane is represented in FIG. 2) is recorded. The master IMU 5 can record its absolute angle in the global coordinate system for this. Alternatively or additionally, the angle sensor 6 can record its angle position, from which the position P.sub.5 can be determined. The movement of the undercarriage 11 during driving operation can hereby also be recorded, and the different behaviour of different drive types, like e.g. caterpillar drive or wheel drive, can be taken into consideration.

[0023] In FIG. 2, only the simple case is considered, in which the speed vs of the master IMU 5 is merely a tangential speed to the radius of the rotational centre of the digger 10. For the calculation of the speed vs of the master IMU 5, the position P.sub.5 of the master IMU 5 and the angular velocity ω of the upper carriage 12 are used in a manner known per se. The calculation occurs directly in the analysis computing unit of the master IMU 5. The speed v.sub.2 of the second IMU 2 is calculated from the position P.sub.2 of the second slave IMU 2 and the angular velocity ω of the upper carriage 12, also in a manner known per se. The position P.sub.2 of the second slave IMU 2 is calculated from the recorded acceleration and rotation rate data of the second slave IMU 2 on the second segment, the slave IMU 1 on the first segment of the digger arm 13 and the master IMU 5 on the upper carriage 12. The data of the slave IMUs 1, 2 is forwarded to the master IMU 5 and the calculation also occurs in the analysis computing unit of the master IMU 5. For calculating the position P.sub.2 of the second slave IMU 2, the master IMU 5 can calculate the absolute angle of the second slave IMU 2 to the X axis of the global coordinate system. Especially for the position component in the X direction, the master IMU 5 can alternatively determine the intermediate angle between the master IMU 5 and the slave IMU 1 on the first segment and the intermediate angle between the slave IMU 1 on the first segment and the second slave IMU 2. The information about the position P.sub.2 is lastly transmitted from the master IMU 5 to the second slave IMU 2.