Method for designing master-slave hand proportion mapping factor of teleoperation robotTechnical Field
The invention relates to the field of teleoperation robots, in particular to a method for designing a master-slave hand proportion mapping factor of a teleoperation robot.
Background
Teleoperated robots, also known as master-slave robots, are a technique in which a person controls a master hand, and in turn indirectly controls a slave robot (slave hand) to realize remote operation. With the expansion of the application field of robots, robots are always faced with unpredictable operation tasks in dangerous and unstructured environments, and compared with traditional autonomous operation methods of robots, remote operation methods have great potential in assisting operators in executing and completing complex and uncertain tasks, and teleoperation robots are widely applied to the fields of telemedicine, sea and air detection, mineral exploitation, remote experiments, explosion venting and the like as tools for completing specific tasks by breaking through space limitations by human beings.
A common master-slave robotic system typically consists of a six-degree-of-freedom master hand and a six-degree-of-freedom robotic arm that moves as a slave hand following the master hand. However, the master workspace is very small compared to the slave workspace if 1 is used: the master-slave robotic system with master-slave mapping is difficult to realize the purpose of quickly controlling the master hand to move the slave mobile manipulator to a longer distance, because the slave hand does not move to a target position when the master hand reaches a working space boundary, generally if the master hand reaches the working space boundary, the master-slave pose mapping relation needs to be disconnected, the master hand is moved to the other side of the working space of the master hand, then the master-slave pose mapping is reestablished, and then the master hand is continuously moved to move the slave mobile manipulator to move towards the target position until the slave mobile manipulator moves to the target position, the whole process often needs to repeatedly connect and disconnect the master-slave pose mapping for many times, and the operation process is inconvenient. In order to ensure the large-range spatial movement of the slave mechanical arm of the master-slave robot system, the master-slave hand proportion mapping relation of K >1 is often adopted in the prior art, but the existing method for adjusting the proportion mapping factor K is only regulated according to human experience, and no standardized method for selecting the master-slave hand proportion mapping factor K according to actual task requirements exists.
Disclosure of Invention
The invention aims to provide a method for designing a master-slave hand proportion mapping factor of a teleoperation robot, which is used for amplifying the motion of a master hand by using the proportion mapping factor KT calculated by the method, so that the slave hand can be moved to a target position before the master hand reaches the boundary of a working space, thereby fully utilizing the motion space of the master hand, breaking through the limitation of small working space of the master hand of a teleoperation robot system and improving the task execution efficiency of the teleoperation robot.
The aim of the invention is realized by the following technical scheme:
a teleoperation robot master-slave hand proportion mapping factor design method comprises the following steps:
Step one: the spatial coordinates Ps0 from the end of the hand and the target point spatial coordinates Ps1 from the hand are acquired, and the target point spatial coordinates Ts from the hand are calculated:
Ts＝Ps1-Ps0 (1)；
Step two: normalizing the Ts vector to obtain a unit vector Tu of a hand expected displacement vector;
Step three: obtaining a current position Pm0 of the main hand, and combining Tu to obtain a relation with a target position Pm1 of the main hand:
Pm1＝Pm0+nTu (3)；
In the above formula (3), n is equal to or greater than 1 and is a constant, and an initial value n1 of n is set to 1;
Setting a stepping value a of n, calculating Pm1 according to the above formula (3), judging whether Pm1 is within the boundary of the main manual space after each calculation, if Pm1 is within the main manual space, changing the value of n to the original value plus the stepping value a, namely ni+1＝ni +a, and substituting ni+1 into formula (3) until the calculated Pm1 is not within the working space, and then calculating a main hand displacement vector Tm according to the following formula (4):
Tm＝(n-a)Tu (4)；
In the above formula (4), n' is the n value calculated last time;
Step four: after determining Tm, a minimum master-slave hand scale mapping factor is determined in conjunction with Ts in step one:
K≥|Ts|/|Tm| (5)；
step five: determining the value of the finally recommended scaling factor KT:
KT＝b(|Ts|/|Tm|) (6)；
in the above formula (6), b is a recommendation coefficient and is greater than 1
Step six: kT is input to the master-slave robotic system.
In the second step, the unit vector Tu of the desired displacement vector from the hand is obtained by normalizing the Ts vector by the following formula (2):
in the fifth step, the recommendation coefficient b is preferably 1.2.
The main manual working space is a cube.
The invention has the advantages and positive effects that:
1. The proportional mapping factor KT calculated by the method of the invention amplifies the movement of the master hand, and can ensure that the slave hand can move to the target position before the master hand reaches the boundary of the working space, thereby fully utilizing the movement space of the master hand, breaking through the limitation of small working space of the master hand of the teleoperation robot system and improving the task execution efficiency of the teleoperation robot.
2. The method is easy to obtain data and simple to realize.
Drawings
Figure 1 is a schematic flow chart of the present invention,
FIG. 2 is a schematic diagram of the variables of the master slave hand according to the present invention.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings.
For convenience of description, the slave manipulator will be referred to as "slave hand" in the following, as shown in fig. 2, the slave manipulator is denoted by Ps0 from the initial hand position, Ps1 from the target hand position, Pm0 from the initial hand position, Pm1 from the target hand position, Tm from the target hand position, Pm0 from the arrow pointing to Pm1 in fig. 2, and Pm1 in the boundary (i.e., one face) of the master hand working space.
The method comprises the following steps:
Step one: based on the slave-arm control system reading the spatial coordinates Ps0 of the current slave hand (i.e., slave-arm), the slave-hand movement target point spatial coordinates Ps1 are obtained using a visual detection technique (visual camera), and the slave-hand desired displacement vector Ts is obtained using the following equation (1):
Ts＝Ps1-Ps0 (1)；
Step two: the unit vector Tu of the desired displacement vector from the hand is obtained by normalizing the Ts vector by the following expression (2):
As shown in fig. 2, Tu is shown by the shorter arrow from Ps0;
Step three: the current position Pm0 of the master hand is obtained by using a master mobile phone robot control system, and then a relation with the target position Pm1 of the master hand is obtained by combining Tu:
Pm1＝Pm0+nTu (3)；
in the above formula (3), n is equal to or greater than 1 and is a constant, and the initial value of n is set to 1;
Setting a stepping value a of n, calculating Pm1 according to the above formula (3), judging whether Pm1 is within the boundary of the main manual space after each calculation, if Pm1 is within the main manual space, changing the value of n to the original value plus the stepping value a, namely ni+1＝ni +a, and substituting ni+1 into formula (3) until the calculated Pm1 is not within the working space, calculating a main hand displacement vector Tm according to the following formula (4):
Tm＝(n-a)Tu (4)；
In the above formula (4), a is a step value, and n' is a last calculated n value; in this embodiment, a=0.01;
Step four: after determining Tm, a minimum master-slave hand scale mapping factor is determined in conjunction with Ts in step one:
K≥|Ts|/|Tm| (5)；
wherein k= |ts|/|Tm | is the minimum scale factor ensuring that the hand of the person moves from the hand to the target position before the movement of the main hand is controlled from its initial position to the boundary;
step five: determining the value of the finally recommended scaling factor KT:
KT＝b(|Ts|/|Tm|) (6)；
In the above formula (6), b is a recommended coefficient and is greater than 1, and in this embodiment, b=1.2. If the minimum value k= |ts|/|Tm | of the scaling factor is taken, although the primary hand can be ensured to move once, the secondary hand can move to a remote target position, but the primary hand is close to the working space boundary, so the scaling factor K cannot be taken to the minimum value, the primary hand is prevented from moving to the working space boundary and reaching the limit on the structure, and the invention sets a recommended coefficient to avoid the situation.
Step six: and inputting the determined master-slave hand proportion mapping factor KT into a master-slave robot system. The proportional mapping factor KT calculated by the method of the invention amplifies the movement of the master hand, and can ensure that the slave hand can move to the target position before the master hand reaches the boundary of the working space, thereby fully utilizing the movement space of the master hand, breaking through the limitation of small working space of the master hand of the teleoperation robot system and improving the task execution efficiency of the teleoperation robot.