Patent ID: 11906392
Assignee: YANSHAN UNIVERSITY
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 2:
3. An in-vehicle stable platform employing active suspension for a six-wheeled vehicle, characterized in that, the in-vehicle stable platform comprises a vehicle body (13), an in-vehicle stable platform (14) fixedly connected with the vehicle body, an inertial measurement device (1), an electronic control device (11), a servo controller set (12), wheels (2.1, 2.2, 3.1, 3.2, 4.1, 4.2), suspension servo actuation cylinders (5.1, 5.2, 6.1, 6.2, 7.1, 7.2) corresponding to the wheels (2.1, 2.2, 3.1, 3.2, 4.1, 4.2) one by one, and corresponding displacement sensors (8.1, 8.2, 9.1, 9.2, 10.1, 10.2);
wherein the inertial measurement device (1) is secured to the in-vehicle stable platform (14), and wheels (2.1, 2.2, 3.1, 3.2, 4.1, 4.2) are connected to a lower part of the vehicle body via the suspension servo cylinders (5.1, 5.2, 6.1, 6.2, 7.1, 7.2) respectively; the displacement sensors (8.1, 8.2, 9.1, 9.2, 10.1, 10.2) are used to measure strokes of the suspension servo actuation cylinders (5.1, 5.2, 6.1, 6.2, 7.1, 7.2), respectively, the electronic control device (11) and the servo controller set (12) are secured to the vehicle body (13), the electronic control device (11) is in communication with the inertial measurement device (1) and the servo controller set (12), the servo controller set (12) is in communication with the displacement sensors (8.1, 8.2, 9.1, 9.2, 10.1, 10.2), and the servo controller set (12) receives the measurement signals of the displacement sensors, the electronic control device (11) reads the orientation parameters measured by the inertial measurement device (1), calculates an amount of extension/retraction of each of the suspension servo actuation cylinders (5.1, 5.2, 6.1, 6.2, 7.1, 7.2) required to cause the in-vehicle stable platform to return to a horizontal level, and outputs it to the servo controller set (12) to control the extension/retraction of each of the suspension servo actuation cylinders (5.1, 5.2, 6.1, 6.2, 7.1, 7.2), so as to cause the in-vehicle stable platform to be horizontal during traveling;
wherein the wheels are divided into three wheel groups, and each of the wheel groups includes two wheels close to one another, when groups are formed, the structure and size of the wheels in some wheel group and the suspension servo actuation cylinder and the displacement sensor are the same, in which the wheels (2.1 and 2.2) are a first group, the wheels (3.1 and 3.2) are a second group, and the wheels (4.1 and 4.2) are a third group; the suspension servo actuation cylinders are also divided into three groups, in which the suspension servo actuation cylinders (5.1 and 5.2) are a first group, the suspension servo actuation cylinders (6.1 and 6.2) are a second group, and the suspension servo actuation cylinders (7.1 and 7.2) are a third group; the displacement sensors are also divided into three groups, in which the displacement sensors (8.1 and 8.2) are a first group, the displacement sensors (9.1 and 9.2) are a second group, and the displacement sensors (10.1 and 10.2) are a third group; upper chambers of the suspension servo actuation cylinders (5.1 and 5.2) are connected via an upper chamber connecting pipeline (15.2), and lower chambers thereof are connected via a lower chamber connecting pipeline (15.1), so that the wheels in the first group form a first support point upper chambers of the suspension servo actuation cylinders (6.1 and 6.2) are connected via an upper chamber connecting pipeline (16.2), and lower chambers thereof are connected via a lower chamber connecting pipeline (16.1), so that the wheels in the second group form a second support point upper chambers of the suspension servo actuation cylinders (7.1 and 7.2) are connected via an upper chamber connecting pipeline (17.1), and lower chambers thereof are connected via a lower chamber connecting pipeline (17.2), so that the wheels in the third group form a third support point a height of each of the support point is controlled by controlling an average amount of extension/retraction of each of the suspension servo actuation cylinders in the group;
wherein the control method of the in-vehicle stable platform employing active suspension for a six-wheeled vehicle comprises in the first step, a coordinate system OXYZ is established and fixedly connected with the vehicle body, a coordinate origin O of the coordinate system is defined as a centroid of all wheel grounding points when the vehicle is horizontal, a positive direction of a Z-axis is an upward direction passing through the origin O and perpendicular to a plane where the in-vehicle stable platform is located; a positive direction of a Y-axis is a forward direction of the vehicle; a right direction when the vehicle moves forward is a positive direction of a X-axis, a heaving displacement of the in-vehicle stable platform along the Z-axis is defined as w, a rotation angle around the X-axis, i.e. a pitch angle is defined as α, and a rotation angle around the Y-axis, i.e. a roll angle is defined as β; in each of scanning periods, the inertial measurement device measures the pitch angle α0 and the roll angle β0 and outputs them to the electronic control device;
in the second step, the electronic control device performs a first-order low-pass filtering with a cutoff frequency fL on the pitch angle α0 and the roll angle β0, and a filtered pitch angle is set as αL, a filtered roll angle is set as βL,
in the third step, according to values of αL and βL obtained in the second step, w=0 and −αL and −βL, are taken as a relative correction value of an orientation of the in-vehicle stable platform, a target value of an average amount of extension/retraction of each of the suspension servo actuation cylinders in each of the wheel groups of the vehicle is calculated through an inverse kinematics algorithm of a vehicle suspension mechanism with three support points, and a target value is transmitted to the servo controller set to perform displacement servo control on the suspension servo actuation cylinders in the wheel groups, so as to cause the in-vehicle stable platform to be horizontal during traveling.