Control method of mechanical arm, mechanical arm assembly, and storage medium

1 . A control method of a mechanical arm, wherein the mechanical arm comprises a parallel platform which comprises a movable platform, a static platform and a telescopic element connecting the movable platform and the static platform, the method comprising:

acquiring a current pose of the movable platform in a mechanical coordinate system, wherein the mechanical coordinate system is a global coordinate system of the mechanical arm where the movable platform is located;

acquiring, according to the current pose of the movable platform, a target pose of the static platform in the mechanical coordinate system; and

performing pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform,

wherein the performing the pose transformation on the static platform includes the current pose of the movable platform in the mechanical coordinate system remaining unchanged during the pose transformation on the static platform.

2 . The method of claim 1 , further comprising:

acquiring an angle of twist between the movable platform and the static platform on a central axis according to the current pose of the movable platform and the target pose of the static platform, and performing rotation transformation on the movable platform according to the angle of twist to return the parallel platform to a zero position.

3 . The method of claim 2 , wherein the target pose is a center of the target pose of the static platform being located on the central axis of the current pose of the movable platform, and the static platform in the target pose being parallel to the movable platform.

4 . The method of claim 3 , wherein the current pose of the movable platform is a pose of the movable platform in the mechanical coordinate system after a reconstruction of a surgical field center of an instrument; and the target pose of the static platform is the pose of the static platform in the mechanical coordinate system after the reconstruction of the surgical field center of the instrument.

5 . The method of claim 4 , wherein the performing the pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform comprises:

acquiring a first transformation matrix from a static coordinate system to a movable coordinate system after returning to a zero position state according to the current pose of the movable platform and the target pose of the static platform; the static coordinate system being a coordinate system where the static platform is located, and the movable coordinate system being a coordinate system where the movable platform is located;

acquiring a second transformation matrix from the static coordinate system to the movable coordinate system before returning to the zero position state; and a third transformation matrix from the mechanical coordinate system to the static coordinate system before performing the pose transformation on the static platform;

acquiring a fourth transformation matrix from the mechanical coordinate system to the static coordinate system after performing the pose transformation on the static platform according to the first, second and third transformation matrices; and

acquiring a fifth transformation matrix between joint coordinate systems of a passive arm in the mechanical arm according to the fourth transformation matrix, and performing transformation on driving parameters of joints of the passive arm according to the fifth transformation matrix, wherein the passive arm is connected to the static platform.

6 . The method of claim 5 , wherein the passive arm comprises a first joint, a second joint, and a third joint in series, wherein posture parameters of the first and third joints remain unchanged, and the third joint is connected to the static platform;

the performing the transformation on the driving parameters of the joints of the passive arm according to the fifth transformation matrix comprises:

acquiring a sixth transformation matrix from the mechanical coordinate system to a coordinate system of the first joint and a seventh transformation matrix from a coordinate system of the second joint to a coordinate system of the third joint;

acquiring an eighth transformation matrix from the first joint to the second joint according to the fifth, sixth and seventh transformation matrices; and

performing the transformation on a driving parameter of the second joint according to the eighth transformation matrix.

7 . The method of claim 4 , wherein the performing the pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform comprises:

acquiring an original pose of the static platform, interpolating the original pose and the target pose of the static platform, acquiring an intermediate pose of the static platform during the pose transformation; and

performing position transformation and posture transformation on the static platform according to the intermediate pose and the current pose of the movable platform.

8 . The method of claim 7 , wherein

the position transformation comprises a circular arc motion transformation with a telecentric fixed point as the center of a circle and a linear motion transformation pointing towards the center of the circle, and

the posture transformation comprises the rotation transformation of a static coordinate system around a Z axis of the mechanical coordinate system and the rotation transformation of the static coordinate system around its own Y axis.

9 . The method of claim 7 , wherein the performing the position transformation and the posture transformation on the static platform according to the intermediate pose and the current pose of the movable platform comprises:

transforming the intermediate pose into a ninth transformation matrix from the static coordinate system to the mechanical coordinate system and a tenth transformation matrix from the static coordinate system to the movable coordinate system, the static coordinate system being a coordinate system where the static platform is located, and the movable coordinate system being a coordinate system where the movable platform is located;

performing transformation on posture parameters of joints of a passive arm according to the ninth transformation matrix and the tenth transformation matrix, wherein the passive arm is connected to the static platform; and

acquiring a second telescopic amount of the telescopic element according to the ninth transformation matrix and the tenth transformation matrix, and adjusting the telescopic element according to the second telescopic amount to make the current pose of the movable platform in the mechanical coordinate system remain unchanged.

10 . The method of claim 9 , wherein the performing the rotation transformation on the movable platform according to the angle of twist to return the parallel platform to the zero position comprises:

interpolating the angle of twist and acquiring an intermediate angle of the movable platform during the rotation transformation; and

perform the rotation transformation on the movable platform according to the intermediate angle and a current angle of the movable platform.

11 . The method of claim 10 , wherein the performing the rotation transformation on the movable platform according to the intermediate angle and the current angle of the movable platform comprises:

acquiring an eleventh transformation matrix between the static coordinate system and the movable coordinate system according to the intermediate angle, acquiring a third telescopic amount of the telescopic element according to the eleventh transformation matrix, and adjusting the telescopic element according to the third telescopic amount to return the parallel platform to the zero position.

12 . The method of claim 11 , further comprising:

after the parallel platform returns to the zero position, acquiring a coordinate of a telecentric fixed point in the static coordinate system after performing the pose transformation on the static platform according to a transformation relationship between the static coordinate system and the mechanical coordinate system after performing the pose transformation on the static platform, wherein the coordinate of the telecentric fixed point in the mechanical coordinate system remains unchanged.

13 . The method of claim 7 , wherein the position transformation and the posture transformation are performed simultaneously.

14 . The method of claim 1 , wherein the performing the pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform comprises:

acquiring a first telescopic amount of the telescopic element according to the current pose of the movable platform and the target pose of the static platform, and when performing the pose transformation on the static platform, adjusting the telescopic element according to the first telescopic amount to make the current pose of the movable platform in the mechanical coordinate system remain unchanged.

15 . The method of claim 1 , wherein the mechanical arm further comprises a passive arm, the passive arm being connected to the static platform,

wherein the performing the pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform comprises:

determining a driving parameter for controlling the passive arm according to the current pose of the movable platform and the target pose of the static platform; and

performing the pose transformation on the static platform by controlling the passive arm based on the driving parameter.

16 . The method of claim 1 , wherein the mechanical arm further comprises a passive arm, the passive arm being connected to the static platform and comprising a plurality of series joints,

wherein the performing the pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform comprises: performing the pose transformation on the static platform through the passive arm according to the current pose of the movable platform and the target pose of the static platform,

wherein when performing transformation on posture parameters of the plurality of series joints of the passive arm, the posture parameters of some joints among the plurality of series joints remain unchanged, and the posture parameters of other joints among the plurality of series joints are changed.

17 . The method of claim 16 , wherein the passive arm comprises a first joint, a second joint, and a third joint in series, wherein the posture parameters of the first and third joints remain unchanged, and the third joint is connected to the static platform.

18 . A mechanical arm assembly, wherein the mechanical arm assembly comprises:

a mechanical arm comprising a parallel platform which comprises a movable platform, a static platform and a telescopic element connecting the movable platform and the static platform; and

a control device configured to perform pose transformation on the static platform on the mechanical arm according to a control method of the mechanical arm, wherein the method comprises:

acquiring a current pose of the movable platform in a mechanical coordinate system, wherein the mechanical coordinate system is a global coordinate system of the mechanical arm where the movable platform is located;

acquiring, according to the current pose of the movable platform, a target pose of the static platform in the mechanical coordinate system; and

performing the pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform,

wherein the performing the pose transformation on the static platform includes the current pose of the movable platform in the mechanical coordinate system remaining unchanged during the pose transformation on the static platform.

19 . A non-transitory readable storage medium, on which an executable program is stored and, when being executed by a processor, implements a control method of a mechanical arm, wherein the mechanical arm comprises a parallel platform which comprises a movable platform, a static platform and a telescopic element connecting the movable platform and the static platform, and the method comprises:

acquiring a current pose of the movable platform in a mechanical coordinate system, wherein the mechanical coordinate system is a global coordinate system of the mechanical arm where the movable platform is located;

acquiring, according to the current pose of the movable platform, a target pose of the static platform in the mechanical coordinate system; and

performing pose transformation on the static platform according to the current pose of the movable platform and the target pose of the static platform,

wherein the performing the pose transformation on the static platform includes the current pose of the movable platform in the mechanical coordinate system remaining unchanged during the pose transformation on the static platform.