JP2909074B2 - Robot arm motion simulator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an operation simulator applied to a manipulator arm of a robot. (Prior Art) FIG. 2 shows the configuration of a conventional robot arm operation simulator. In the figure, the joint angles of the robot arm are previously configured based on the output signal of the data input to the position and posture data input device 11 of the robot arm tip and the current joint angle signals of the robot arm 4. It is calculated and calculated by the coordinate conversion calculating device 2. The output signal of the arithmetic unit 2 is input to the control unit 3 of the robot arm, and is compared with the displacement and velocity of each joint angle of the robot arm by the control unit 3 to become a drive signal of the robot arm. The robot arm 4 performs desired joint angle operations following the drive signal input from the control device 3. In this way, the position and orientation of the tip of the robot arm are
The operation according to the command given by the position / posture data input device 11 is performed every moment. In the device, a coordinate transformation calculating device configured in advance based on the position data and posture data of the robot arm tip input by the position / posture data input device 11 and the current joint angle signal of the robot arm 4. According to 2, the joint angle of the robot arm at the next time point is calculated. Conventionally, since the configuration of the arithmetic device is a fixed type, when the configuration of the robot arm is changed, the configuration of the arithmetic device is accordingly changed. Also, it is necessary to change each time, and when there is an obstacle around the robot, it cannot be automatically avoided to drive the robot arm.
In addition to the inconvenience, in the case of a robot having more than six degrees of freedom, simulation becomes extremely complicated, and it is difficult to quickly respond to the case where different types of robot arms are placed under different environmental conditions. . (Problems to be Solved by the Invention) As described above, the conventional operation simulator of a robot arm does not have general versatility. Each time it is attempted to avoid obstacles in the robot, it is necessary to change the configuration of the coordinate transformation calculation device, and when there is an obstacle around the robot, It is very inconvenient to operate the robot in such a way as to avoid the robot arm part, and when changing the position and posture of the robot arm tip, the final target position (including posture) is given. In addition, there was an inconvenience that it was necessary to give the trajectory (position and attitude) leading to that. The most important thing to keep in mind when designing a robot is to carefully consider what the robot's intended task is and under what environment. In particular, in a robot with a multi-joint structure, an inoperable space area (an inoperable area even within the distance that should be reached from the length of the robot arm) occurs depending on the number and structure of joints. In the case where the vehicle cannot pass through, or work in an environment where there is an obstacle, an inoperable region occurs. In conventional simulators, the main issue is how to move a given robot, and it has been studied by repeating simulations for that purpose. Eliminating this inoperable space is essentially essential in such simulations. Can not be resolved. In view of this point, the present invention is capable of freely changing and examining the number of robot joints and the structure itself. In the robot working environment, the optimum structure (number of joints and arms) for achieving the target work is considered. (Dimensions, shapes, etc.) can be determined. Therefore, this operation simulator device is not only a device for simply viewing the operation of a robot in a graphic form, but also has a role of enabling a design that includes the basic structure of the robot. (Means for Solving the Problem) For this reason, the present invention provides position data and posture data of a robot arm, calculates each joint angle of the arm by a coordinate transformation calculating device, and drives the robot arm based on the calculation result. Device that simulates the operation of the robot arm by using the output signal from the input device of each data of the target position / posture data of the robot arm, the mechanism / structure data of the robot, and the obstacle data around the robot. A trajectory calculation device that calculates the tip trajectory of the robot arm; and a coordinate conversion calculation device that compares the calculation result of the trajectory calculation device with the actual signal of each joint angle of the robot arm and calculates each joint angle within the obstacle avoidance range. Calculating the displacement and velocity of each joint angle of the robot arm from the calculation result of the coordinate conversion calculation device, and based on the calculation result. And a control device for outputting a drive signal of the robot arm to the drive unit, which is used as a means for solving the problem. (Operation) When changing the robot arm, input data on the mechanism and structure of the new robot arm into a separate input device,
The output signal from the input device is subjected to arithmetic conversion by mathematical processing and output to the coordinate conversion device. In addition to the input signals, an input signal relating to the target position and orientation of the tip of the robot arm, a joint angle signal of the robot arm, and an output signal of the obstacle avoidance trajectory calculator are input to the coordinate transformation calculation device. The joint angle at the next time is calculated based on these signals. The calculation result is sent to the control device, and the control device performs arithmetic processing on the joint angular displacement and the speed of the robot arm, and sends a drive signal of the robot arm to the drive unit of the robot arm. (Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of the present invention. Reference numeral 1 denotes a trajectory calculation device for calculating a trajectory of the tip of the robot arm. The calculation device 1 receives signals of a target position / posture data signal of the tip of the robot arm, a data signal for each robot model and an obstacle data signal. Then, based on these data signals, a reasonable tip trajectory of the robot arm that avoids obstacles is calculated and determined according to the robot model. The target position / posture data signal of the tip of the robot arm is an output signal from the input device 10 into which the position data and the posture data of the target robot tip are input, and the model-specific data signal of the robot is robot mechanism data. And data signals from the input device 5 to which the structural data has been input, are processed by mathematical processing in the arithmetic unit 6 and are converted and output. The obstacle data signal is the shape and position data of the obstacle around the robot. Is an output signal from the input device 7 to which is input. Numeral 2 denotes a coordinate transformation arithmetic unit which receives the output signal of the operation result of the trajectory arithmetic unit 1 and receives the current joint angle signals of the robot arm and the robot mechanism / structure data signal by the arithmetic unit 6 at the same time. Calculate the joint angles of the robot arm at the next time. This calculation result is sent to the control device 3 and also output to the obstacle avoidance range calculation device 7 together with the data signal of the obstacle input device 9, and the calculation device 7 determines the obstacle avoidable range of the robot arm. The calculation is performed, and the calculation result is sent to the display device 8 and, at the same time, is returned to the coordinate transformation calculation device 2. The output signal of the coordinate transformation calculation device 2 is input to the control device 3 of the robot arm as described above, and the joint angle displacement and the speed of the robot arm are calculated together to become a drive signal of the robot arm. The robot arm 4 operates at a predetermined displacement and speed at each joint angle following the drive signal input from the control device 3. In the device according to the present invention, even if the mechanism and structure of the robot are changed as described above, it is not necessary to change the coordinate transformation operation device 2 and the data relating to the mechanism and structure of the robot can be input to the data input device 5 so that In addition to the obstacles in the environment where the robot is placed, the robot arm calculates the trajectory that achieves the target posture while avoiding obstacles, and along the trajectory, The arm can also be operated without colliding with an obstacle. (Effect of the Invention) A mathematical expression describing the motion of a robot includes a mathematical expression called Jacobian. This is an indispensable mathematical expression for calculating each joint angle from the given hand trajectory of the articulated robot, which is very complicated. When the number of joints changes, the shape (structure) of the formula itself changes significantly, and it is necessary to reconstruct the formula by manual calculation, but the change is not easy. In many cases, an ordinary simulator is designed for a specific robot that does not change the number of joints, and the values to be changed are values such as the thickness of the arm and the length of the arm. If only the thickness of the arm or the length of the arm is to be changed, it is not necessary to change the structure of the formula, and it is possible to easily cope with it only by changing only the coefficient in the formula. The conventional one is basically a simulator that follows this idea. The present invention is adapted to cope with various robots having different numbers of joints, even if the number of joints is changed. For this purpose, a mathematical formula processing device is provided. That is,
According to the present invention, the structure and mechanism of different types of robots are input to another input device. Based on this, the trajectory of the arm tip is calculated, and the robot arm can be operated along the trajectory without colliding with obstacles. As a general-purpose robot arm simulator, the operation of the robot arm can be quickly studied. It becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a robot arm operation simulator device showing a typical embodiment of the present invention, and FIG. 2 is a block diagram of a conventional device. Description of main parts of the drawing 1 trajectory calculation device 2 (coordinate conversion) calculation device 3 control device 4 robot arm 5 (mechanism / structure) input device 6 (formula of mechanism / structure) Processing) Computing device 7 (obstacle) avoidance range computing device 8 Display device 9 Obstacle (shape / position) input device 10 (Target position / posture) input device 11 Input device

Claims (1)

(57) [Claims] Given a position data and a posture data of the robot arm, each joint angle of the arm is calculated by a coordinate transformation calculating device, and based on the calculation result, the robot arm is driven to simulate the operation of the robot arm. A trajectory calculation device for calculating a trajectory of the tip of the robot arm based on an output signal from an input device for inputting data of tip target position / posture data, robot mechanism / structure data, and obstacle data around the robot; And a real-time signal of each joint angle of the robot arm, and calculates a joint angle within the obstacle avoidance range. Calculates the angular displacement and velocity together and outputs a drive signal of the robot arm to the drive unit based on the calculation result. Operation simulator apparatus for a robot arm, characterized in that it consists of a device.