Robot system with independently controllable higher-order derivatives

Abstract

A robotic system with independently controllable higher order derivatives is disclosed. An indication of a trajectory along which an end effector of the robot arm should be moved is received. A plan is determined utilizing a combination of one or more motors and one or more energy removal devices to move one or more elements of the robot arm such that the end effector is moved through the trajectory, including using one or more motors to apply torque to one or more elements of the robot arm during a first interval and using one or more energy removal devices to remove energy from one or more of the elements during a second interval beginning after the start of the first interval. Commands to execute the plan are transmitted via a communications interface.

Description

Cross-reference to other applications

[0001] This application claims priority based on U.S. Provisional Patent Application No. 63 / 301,693, entitled "ROBOTIC SYSTEM WITH INDEPENDENTLY CONTROLLABLE HIGHER DERIVATIVES," filed on January 21, 2022, which is hereby incorporated by reference in its entirety for all purposes.

Background Art

[0002] Robots (robot arms and end effectors (e.g., suction bases, grippers, etc.)) are actuated using motors, pneumatic pistons, vacuum / suction, and other actuators. A robot arm or other robot may be operated under the control of a control system, which sends commands to control the operation of the actuators in order to move the robot (e.g., to grasp and move an object, etc.). A robot control system may control one or more of the position, velocity, acceleration, or other higher derivatives of the motion of the robot and / or a part thereof (such as an end effector), and / or the torque and / or current applied by / to the actuators.

[0003] Critical control (fast rise, critical damping, non-over shoot) requires accurate damping regardless of whether it controls position, velocity, torque, current, etc. Accurate damping requires the estimation of the derivative of the controlled state, or, if the system is of higher than second order and has changed dynamics, even higher order derivatives.

[0004] Finding instantaneous values ​​of these higher-order derivatives is extremely difficult. The sensor is likely measuring the state, not the derivative of the state. The sensor is digital, the algorithm runs on the CPU, and it has inherent latency. Estimating the state of higher-order derivatives is difficult and error-prone, causing instability and false energy injection when attempting to control a system (such as a robotic system). Thus, instantaneous measurements are always delayed, the sensor is always noisy, the derivative of the noise produces a very noisy result, requiring filtering and producing inaccurate estimates, and CPU jitter and latency introduce even larger errors in both magnitude and phase.

[0005] Ultimately, controlling the higher-order derivatives is the most difficult. Since there are no levels of higher-order derivatives that can be directly controlled, energy must be injected at the appropriate time to control the derivative state. If the amount or timing of the injected energy is inappropriate, unexpected results can be obtained (e.g., instability, insufficient settling time, suboptimal control, etc.). [Brief explanation of the drawing]

[0006] Various embodiments of the present invention are disclosed in the following detailed description and accompanying drawings.

[0007] [Figure 1A] A diagram illustrating one embodiment of a robot system with independently controllable higher-order derivatives.

[0008] [Figure 1B] A diagram illustrating one embodiment of a robot system with independently controllable higher-order derivatives.

[0009] [Figure 2] A diagram showing one embodiment of a robot system control element.

[0010] [Figure 3] A diagram illustrating one embodiment of a robot system with independently controllable higher-order derivatives.

[0011] [Figure 4A] A flowchart illustrating one embodiment of a process for controlling a robot system with independently controllable higher-order derivatives.

[0012] [Figure 4B] A flowchart illustrating one embodiment of a process for controlling a robot system with independently controllable higher-order derivatives.

[0013] [Figure 5A] This figure shows a comparison between the velocity profile of a conventional robot and the velocity profile of a robot system with independently controllable higher-order derivatives.

[0014] [Figure 5B] A diagram showing the energy applied by actuators and braking elements to control a robot system with independently controllable higher-order derivatives. [Modes for carrying out the invention]

[0015] The present invention can be implemented in various forms, including processes, apparatus, systems, compositions of materials, computer program products embodied on computer-readable storage media, and / or processors (processors configured to execute instructions stored and / or provided by memory connected to the processor). In this specification, these embodiments or any other forms the present invention may take may be referred to as "technologies." Generally, the order of the processes of the disclosed processes may be modified within the scope of the invention. Unless otherwise specified, components such as processors or memory described as configured to perform a task may be implemented as general components temporarily configured to perform a task at a given time, or as specific components manufactured to perform a task. In this specification, the term "processor" refers to one or more devices, circuits, and / or processing cores configured to process data such as computer program instructions.

[0016] The following provides a detailed description of one or more embodiments of the present invention, with reference to drawings illustrating the principles of the present invention. While the present invention is described in relation to such embodiments, it is not limited to any of these embodiments. The scope of the present invention is limited only by the claims, and the present invention includes many substitutes, variations, and equivalents. The following description includes many specific details to provide a complete understanding of the present invention. These details are illustrative, and the present invention can be implemented in accordance with the claims without some or all of these specific details. For simplicity, technical matters well known in the art related to the present invention are not described in detail, so as not to complicate the present invention unnecessarily.

[0017] Techniques for controlling the derivatives (e.g., velocity, acceleration) of a robot state are disclosed, with or without estimation of the derivative state itself. In various embodiments, one or more electrical, electromagnetic, and / or electromechanical components are provided and utilized to inject energy at appropriate times to control the derivative state. In some embodiments, passive elements are used to control the dynamics of the system with guaranteed stability.

[0018] In various embodiments, robot control actuators are used that do not require state estimation and act directly at the level of higher derivatives. For example, in some embodiments, one or more of various types of brakes may be used to directly reduce speed.

[0019] In some embodiments, actuators are used that are truly passive while attempting to control them, although estimation may be required, thus ensuring they remain stable. Examples include, but are not limited to, resistors, capacitors, and other energy storage elements.

[0020] In some embodiments, motors are constructed having control systems incorporating the higher-order derivative control techniques disclosed herein. Conventional drivetrain assemblies utilize brakes only to abruptly stop the system or remove regenerative braking energy. In various embodiments, braking is used as an integral part of the control system, reducing the need for the actuator itself (e.g., a robotic joint motor) to decelerate the system or remove energy.

[0021] In some embodiments, a combination of a brake and a purely passive element (such as a braking resistor) is used to schedule operation at different times and states for optimal utilization of the actuator. These higher-order derivative control elements have much higher capabilities than the actuator, allowing the motion to be immediately damped, simplifying the control, and shortening the time required to reach the target state.

[0022] In various embodiments, velocity (or other higher-order derivative level) control is performed at least in part as described in U.S. Patent Application No. 17 / 482,162, filed September 22, 2021, titled "Velocity Controlled-based Robotic System," published as U.S. Patent Application Publication No. 2022-0088778 on March 24, 2022, the entire contents of which are incorporated herein by reference for all purposes.

[0023] In various embodiments, a brake or similar energy removal system is used to directly control the speed by removing energy using a structure that cannot add energy. Conventionally, reverse motor torque has been used to decelerate and stop the movement of a robotic arm. However, the latency or signal noise during measurement (especially at low speeds) can lead to errors in speed estimation. If the motion oscillates such that the robot / its components are moving in the opposite direction of what was estimated, the application of torque intended to decelerate the motion may instead add energy and increase the motion, resulting in instability and delay as the system adjusts and damps the oscillation. Utilizing a brake or a similar device or system that can only remove energy ensures that such results or conditions do not occur.

[0024] In some embodiments, the braking systems disclosed herein apply a braking force to a motor or motor shaft. In some embodiments, the motor and motor shaft drive a reduction gearbox that drives a joint, and the braking force disclosed herein is applied on the output side of the gearbox to reduce wear and breakage of the gearbox (compared to, for example, applying a reverse torque using a motor to remove energy).

[0025] Figure 1A shows an embodiment of a robotic system having independently controllable higher-order derivatives. In the example shown, the robotic system and environment 100 include a robotic arm 102 having a suction-type end effector 104. The robotic arm 102 comprises several segments connected by joints 102a, 102b, and 102c. In some embodiments, the robotic arm 102 includes a 6-degree-of-freedom (DOF) industrial robot. In some embodiments, the robotic arm 102 has more or fewer degrees of freedom than 6. Motors and associated motor controllers are provided at each of the joints 102a, 102b, and 102c to bend or rotate the associated segments of the robotic arm 102 by, for example, supplying voltage and current to the motors to apply torque, thereby moving the associated segments in one of the 6 (or more than 6) degrees of freedom.

[0026] In the example shown in the figure, the robot arm 102 and the end effector 104 communicate wirelessly with the control computer 106. In some embodiments, the control computer 106 is integrated into and / or with the robot arm 102. For example, the control computer 106 may be an internal processor that makes up the robot arm 102, or a processor or computer mounted on or inside the same chassis as the robot arm 102.

[0027] In the context shown in Figure 1A, the robot arm 102 and end effector 104 are configured to be used to pick items from a conveyor 108 and place them on a pallet 110 under the control of a control computer 106. Three-dimensional (or two-dimensional) image / depth data from a camera 112 is received by the control computer 106 and used to generate a three-dimensional view of the workspace shown in Figure 1A. In various embodiments, the control computer 106 includes a computer vision subsystem configured to construct such a view. Image data is used in various embodiments by the control computer 106 to identify an item (such as item 114 in the example shown) as the next item to be picked / placed. Image data and / or other center data and / or stored data may be used to determine one or more attributes of item 114 (size, shape, weight, material, stiffness, etc.). Such attributes may be used to determine a strategy for grasping, moving, and / or placing item 114. Once item 114 is grasped, further attributes may be determined, such as its weight and the quality of the grip (e.g., the suction force measured by a pressure sensor).

[0028] In various embodiments, the control computer 106 determines a plan and strategy for grasping an item (such as item 114). As shown in Figure 1A, the end effector 104 is moved toward item 114, as indicated by an arrow extending from near the end effector 104. In various embodiments, the robotic arm 102 includes, in one or more of the joints 102a, 102b, and 102c, a motor and associated control unit for applying torque to move the relevant components constituting the robotic arm 102 in a first direction (e.g., forward) for each degree of freedom in each such joint, and a brake or other energy removal device (and associated actuator) configured to apply energy in the opposite (reverse) direction to the first direction. Using a model of the robotic arm 102 and its motor and brake, the control computer determines and executes a set of control commands to actuate the joint motors or a subset thereof to move the end effector 104 along a trajectory to a position where it can grasp item 114. The end effector 104 is moved at a relatively high speed (e.g., at or near the maximum speed) to a position relatively close to item 114, and then a braking (or other energy removal) system is activated at a precise timing to allow the speed of the end effector 104 to be reduced to zero relatively close to item 114 without overshoot or vibration.

[0029] Once item 114 is grasped, for example, by moving a suction cup located on the underside of the end effector 104 so that it is in contact with or near item 114 and applying a suction force to grasp item 114, item 114 is moved along a trajectory to the destination position where item 114 is placed. In various embodiments, the maximum speed at which item 114 and the end effector 104 are moved through the workspace is determined based on, for example, one or more attributes or limitations of the robot arm 102, the end effector 104, and / or item 114. For example, the maximum speed may be slower if item 114 is heavy or if a pressure sensor indicates that the grip is not strong enough.

[0030] Figure 1B shows an embodiment of a robotic system with independently controllable higher-order derivatives. In the example and state shown in Figure 1B, item 114 is already grasped and moved to a determined destination position indicated by a dashed contour on the top surface of the pallet 110. The arrows extending from near the end effector 104 indicate the vectors that item 114 follows as it is moved to the destination position. In various embodiments, item 114 is moved at or near the maximum speed (e.g., the maximum speed of the robotic arm 102, or the maximum speed determined to move item 114 under the conditions shown in the figure).

[0031] In various embodiments, the trajectory and associated planned control signals for moving item 114 to a destination position include applying torque (at or near maximum) to one or more motors associated with joints 102a, 102b, and / or 102c during at least a portion of the first interval, and activating a brake or other energy-reducing device during a second interval that begins after the start of the first interval. The brake or other energy-reducing device allows the robot arm 102 and end effector 104 to move at or near maximum speed and then decrease relatively quickly, with or without the ability to directly control speed and measure or estimate speed.

[0032] Figure 2 shows one embodiment of a robot system control element. In the illustrated example, the control computer 106 transmits a (e.g., digital) control signal 206 to a motor controller 202 that controls the motor 204. For example, each of the joints 102a, 102b, and 102c may have one or more motors 204, and each of those motors may have an associated motor controller 202. The motor controller 202 provides the motor 204 with voltage, current, and / or other analog or low-level inputs to cause the motor 204 to operate over a controlled interval and / or to apply a controlled amount of torque. The motor 204 optionally provides position, temperature, speed, or other feedback 210 to the controller 202, and the controller 202 optionally provides associated feedback signals 212 to the control computer 106.

[0033] Feedback 210, 212 may, in various embodiments, include position or other information available for estimating the state. However, as described above, measured information may be inaccurate, and there is always some latency in converting the measured state information into an estimated state of the robot and / or its components, particularly for velocity or other higher derivatives of position. In various embodiments, velocity control is provided as disclosed herein without (necessarily) estimating higher derivatives of the state, and a more efficient and optimized use of the robot is possible, such as by controlling the robot using velocity (or other higher derivative) control.

[0034] Figure 3 shows one embodiment of a robot system with independently controllable higher-order derivatives. In the example shown, in addition to the control and drive elements shown in Figure 2, the control computer 106 is configured to provide a control signal 306 to an energy removal device controller 302, which is configured to activate the energy removal device 304 (e.g., one or more braking systems or devices) by transmitting a low-level signal 308 and / or applying voltage, current, pneumatic pressure, etc., in order to activate the energy removal device 304.

[0035] In the example shown in the figure, the energy removal device 310 provides the measured information 310 to the energy removal device controller 302, which then provides the status information 312 to the control computer 106. The information 310 and 312 may be used in various embodiments to monitor and control the operation of the energy removal device 304.

[0036] Calculating the velocity of robot elements (such as end effectors or joints) is difficult, and controlling them is even more challenging. To eliminate velocity from the robot system, in various embodiments, a force is applied in the opposite direction to the robot / joint movement.

[0037] When velocity is fluctuating, the application of force must be precisely timed; applying it out of phase will increase the velocity instead of decreasing it. Therefore, in conventional robots having only articulated motors, for example, it is difficult to accurately decelerate the robot simply by applying current to the motors, especially when it is fluctuating. The solutions disclosed herein, as implemented in several embodiments, include a braking system or other energy removal system or device for removing velocity. In various embodiments, a control input directly proportional to the amount of velocity to be removed is determined and applied to the braking system. Examples of such braking systems or devices include, but are not limited to, eddy current brakes, braking resistors, and other non-contact brakes, as well as disc brakes and other friction brakes.

[0038] In some embodiments, eddy current brakes are used to remove energy from robotic arm elements (such as joints driven by articulated motors). Eddy current brakes (also known as induction brakes, electric brakes, or electric retarders) are devices used to slow down or stop a moving object by generating eddy currents. In some embodiments, a non-ferromagnetic conductive disk rotates perpendicularly through a toroidal magnetic field. As the disk rotates, it induces eddy currents. The power is then dissipated throughout the disk, generating a braking torque force.

[0039] In various embodiments, the braking systems described herein do not require velocity estimation because their engagement directly removes velocity / energy. In various embodiments, the braking system is selectively engaged while an actuator (such as a motor) is adding energy to remove the damping term in motor control, thereby eliminating the velocity estimation step and the need for motor current damping. In various embodiments, precisely controlled versions of these braking systems are used to precisely control velocity / energy removal instead of merely a general "brakeman".

[0040] Another method of removing energy that is still passive involves a braking resistor on the motor. A motor has coils that rotate within a magnetic field, and coils rotating within a magnetic field induce an electromotive force (EMF). This EMF, also known as "reverse EMF," acts against the applied voltage that first rotates the motor, reducing the current flowing through the motor's coils. The motor reverse EMF voltage is directly proportional to the motor speed. In various embodiments, a resistor is selectively engaged across the motor wiring to remove energy and reduce speed.

[0041] Figure 4A is a flowchart illustrating one embodiment of a process for controlling a robotic system having independently controllable higher-order derivatives. In various embodiments, process 400 in Figure 4A may be performed by a control computer (such as the control computer 106 in Figures 1A and 1B). In the example shown, in step 402, the next segment of the trajectory is determined. For example, referring to Figure 1A, a trajectory may be determined for moving the end effector 104 from the position shown in the figure to a gripping position adjacent to item 114. In step 404, combinations and sequences for applying motor torque and braking to each of the one or more motors and / or joints constituting the robotic arm 102 are determined in order to move the end effector 104 along the planned trajectory. In various embodiments, models of the robotic arm 102 and its motors, controllers, and braking systems may be used to determine at least locally optimal and / or feasible sequences for applying motor torque and braking to coordinately move the elements of the robotic arm 102 to move the end effector 104 along the determined trajectory / segment. In step 406, the motor and braking systems are controlled in a determined sequence to synchronously apply torque and remove energy by braking, so as to rapidly move the end effector 104 through the determined trajectory / section.

[0042] Figure 4B is a flowchart illustrating one embodiment of a process for controlling a robot system with independently controllable higher-order derivatives. In various embodiments, the process in Figure 4B performs step 406 of Figure 4A. In the example shown, in step 420, a corresponding signal is sent to the associated motor controller for each of one or more motors to apply torque at a specified amount for a specified time. In step 422, a control signal is sent to a braking system (or other energy removal system or device) to remove energy at a predetermined time and / or according to a predetermined profile (e.g., varying the degree or amount of energy removal over time, e.g., how much braking force is applied over time). In various embodiments, the braking force begins to be applied after the corresponding motor torque has been applied, e.g., over a specified or calculated interval. In step 424, final adjustments may be made as needed to complete the trajectory / section. For example, if braking stops the end effector just before its final position, a small amount of torque may be applied over short intervals to move the end effector 104 further into place. In the case of placing, force control may be used to precisely position an item (such as item 114) in place (for example, adjacent to one or more previously placed items).

[0043] Figure 5A shows a comparison of the velocity profile of a conventional robot with the velocity profile of a robot system with independently controllable higher-order derivatives. The x-axis corresponds to time, and the y-axis represents velocity (velocity of the end effector 104, or joint actuators (e.g., motor or gearbox output shaft), or structures constituting or mechanically coupled to the joint, etc.). The horizontal line "Vmax" represents the maximum velocity, which may reflect one or more of the physical limitations of the robot arm 102, as well as the maximum velocity at which the end effector 104 (or other structure) should move, given one or more attributes of the item being moved (e.g., weight) and / or dynamically measured / determined factors (e.g., gripping quality). The dashed curve 502 shows an example of velocity over time for moving an item from a starting position {x0, y0, z0} to a destination position {x1, y1, z1} using velocity control (or other control) without utilizing the energy removal systems / devices disclosed herein. In the example shown in the figure, the end effector 104 (or other structure) does not reach its maximum speed Vmax before it becomes necessary to begin decelerating in order to allow zero velocity to be achieved when the end effector 104 reaches the arrival position {x1, y1, z1} at the time in this example.

[0044] The solid curve 504 shows the velocity profile that can be achieved when moving the same item from a starting position {x0, y0, z0} to a destination position {x1, y1, z1} using velocity control (or other control) while utilizing the energy removal system / device disclosed herein. In the example shown, since the same actuator (e.g., motor) is used, the end effector (or other structure) accelerates in the same way as shown in curve 502, but the structure continues to accelerate to achieve a speed near the maximum speed Vmax / maximum speed Vmax before the speed is rapidly and directly reduced by the operation of the braking system (or other direct energy removal device / system) (the speed may be sustained over a certain interval in various embodiments). The use of the technology disclosed herein moves the item much faster over time t than when braking / energy removal is not used, as shown in curve 502. new This makes it possible to reach the destination position {x1, y1, z1} by a certain time.

[0045] Figure 5B shows the energy applied by actuators and braking elements to control a robotic system having independently controllable higher-order derivatives as a function of time (or position). In various embodiments, Figure 5B shows energy addition and removal profiles related to the velocity profile shown in Figure 5A. In the example shown, curve 522 is shown as a dashed line including a first (left / energy addition) portion 522a and a second (right / energy removal) portion 522b, and shows the application of torque when direct energy removal using brakes or other energy removal systems described herein is not utilized to achieve the velocity profile 502 of Figure 5A. Portion 522a shows energy added by applying torque, for example, using an articulated motor, and portion 522b shows energy removal, for example, by applying torque in the opposite direction.

[0046] Curve 524 shows the application of torque synchronized with the direct removal of energy, for example by braking, as shown by curve 526, in order to achieve the speed profile shown by curve 504 in Figure 5A by directly reducing the speed of the end effector through energy removal (e.g., braking). Energy is added in the same way, as shown by the coincidence of curve 524 and curve portion 522a, but by utilizing the brakes or other direct energy removal systems disclosed herein, energy can be removed much more directly and quickly without the risk of overshoot or error, and over time t new Complete energy removal can be achieved by then.

[0047] In Figure 5B, the braking mechanism is represented by curve 524 such that braking coincides with torque application, at time t brake Although it is shown to apply in the above, in various embodiments the torque application interval may or may not overlap with the braking application interval.

[0048] The techniques disclosed herein enable speed control without necessarily and / or rapidly / accurately estimating the state of the robot system and / or its derivatives (such as velocity). In various embodiments, active and / or passive elements are used to remove energy from the robot's constituent elements (such as any motor or joint), enabling direct control of velocity with or without estimation of the state of velocity or other derivatives. Such direct control of velocity (or higher derivatives) that does not depend on state estimation enables the implementation of velocity and higher derivative control, potentially allowing for more effective and / or optimal utilization of the robot arm or other robot, including achieving higher end-effector speeds before the energy removal system is used to decelerate / stop the end-effector, and ultimately enabling higher throughput and utilization. In various embodiments, the control structures and techniques disclosed herein enable precise control of such systems, thus enabling the provision of very powerful, high-performance, and high-gain systems.

[0049] Although the embodiments described above have been explained in some detail for the sake of clarity, the present invention is not limited to the details provided. Many alternative methods exist for carrying out the present invention. The disclosed embodiments are illustrative and not intended to be limiting. [Application Example 1] A robot system, Communication interface, A processor connected to the aforementioned communication interface, Equipped with, The aforementioned processor, The end effector that makes up the robot arm receives instructions for the trajectory it should move along. A plan is determined to use the one or more motors and the one or more energy removal devices in combination to move the one or more elements constituting the robot arm so that the end effector moves along the trajectory, including applying torque to one or more elements constituting the robot arm using one or more motors during a first interval, and removing energy from one or more of the elements using one or more energy removal devices during a second interval starting after the start of the first interval, A system configured to send commands for executing the plan via the aforementioned communication interface. [Application Example 2] The system described in Application Example 1, wherein the orbit includes a longer orbital section. [Application Example 3] The system described in Application Example 1, wherein the processor is configured to determine the trajectory. [Example 4] A system according to Example 1, wherein the commands for executing the plan include a first set of commands for causing the one or more motors to apply torque to the one or more elements constituting the robot arm during the first interval. [Application Example 5] The system described in Application Example 4, wherein the first set of commands includes one or more commands that are transmitted to corresponding motor controllers via the communication interface. [Application Example 6] A system according to Application Example 5, wherein the command for executing the plan includes a second set of commands causing the one or more energy removal devices to remove energy from one or more of the elements during the second interval. [Application Example 7] The system described in Application Example 1, wherein the second interval begins before the end of the first interval. [Application Example 8] The system described in Application Example 1, wherein the second interval does not overlap with the first interval. [Application Example 9] A system according to Application Example 1, further comprising the energy removal device, braking system, or device. [Application Example 10] The system described in Application Example 1, wherein the energy removal device directly controls the speed of the one or more elements constituting the robot arm. [Application Example 11] The system described in Application Example 1, wherein the energy removal device directly controls the speed of the end effector. [Application Example 12] A system according to Application Example 1, wherein the plan for using a combination of one or more motors and one or more energy removal devices to move one or more elements constituting the robot arm is determined without estimating the state of the robot system. [Application Example 13] The system described in Application Example 1, wherein the plan for using a combination of one or more motors and one or more energy removal devices to move one or more elements constituting the robot arm is determined without estimating the state of the derivative of the robot system. [Application Example 14] A system according to Application Example 1, wherein using one or more motors and one or more energy removal devices in combination to move one or more elements constituting the robot arm enables the end effector to move along the trajectory in a shorter time than would be required if only the one or more motors were used. [Application Example 15] A system according to Application Example 1, wherein using one or more motors and one or more energy removal devices in combination to move one or more elements constituting the robot arm increases the throughput of the robot system compared to the throughput achieved when only the one or more motors are used. [Application Example 16] A method for controlling a robotic system, The end effector that makes up the robot arm receives instructions for the trajectory it should move along. A plan is decided to use one or more motors and one or more energy removal devices in combination to move the one or more elements constituting the robot arm so that the end effector moves along the trajectory, by using one or more motors to apply torque to one or more elements constituting the robot arm during a first interval, and using one or more energy removal devices to remove energy from one or more of the elements during a second interval that begins after the start of the first interval, Sending commands to execute the plan via a communication interface, A method that includes [a certain feature]. [Example 17] A method according to Example 16, wherein the commands for executing the plan include a first set of commands for causing the one or more motors to apply torque to the one or more elements constituting the robot arm during the first interval. [Example 18] A method according to Example 17, wherein the first set of commands includes one or more commands transmitted to corresponding motor controllers via the communication interface. [Example 19] A method according to Example 18, wherein the commands for carrying out the plan include a second set of commands causing the one or more energy removal devices to remove energy from one or more of the elements during the second interval. [Application Example 20] A computer program product which is embodied in a non-temporary computer-readable medium, Computer commands for receiving instructions on the trajectory to which the end effector constituting the robot arm should move, A computer instruction for determining a plan for using one or more motors and one or more energy removal devices in combination to move the one or more elements constituting the robot arm so that the end effector moves along the trajectory, by using one or more motors to apply torque to one or more elements constituting the robot arm during a first interval, and using one or more energy removal devices to remove energy from one or more of the elements during a second interval that begins after the start of the first interval, and A computer instruction for sending a command to execute the plan via a communication interface, A computer program product that includes the following features.

Claims

1. It is a robotic system, Communication interface, A processor connected to the aforementioned communication interface, Equipped with, The aforementioned processor, The end effector that makes up the robot arm receives instructions for the trajectory it should move along. A plan is determined to use a combination of one or more motors and one or more energy removal devices different from the one or more motors to move one or more elements constituting the robot arm so that the end effector moves along the trajectory, the plan being to apply torque to one or more elements constituting the robot arm using one or more motors during a first interval, and to remove energy from one or more of the elements using one or more energy removal devices during a second interval that begins after the start of the first interval, A system configured to send commands for executing the plan via the aforementioned communication interface.

2. A system according to claim 1, wherein the track includes a plurality of sections.

3. A system according to claim 1, wherein the processor is configured to determine the trajectory.

4. A system according to claim 1, wherein the commands for executing the plan include a first set of commands for causing the one or more motors to apply torque to the one or more elements constituting the robot arm during the first interval.

5. The system according to claim 4, wherein the first set of commands includes one or more commands transmitted to corresponding motor controllers via the communication interface.

6. The system according to claim 5, wherein the command for executing the plan includes a second set of commands for causing the one or more energy removal devices to remove energy from one or more of the elements during the second interval.

7. The system according to claim 1, wherein the second interval begins before the end of the first interval.

8. The system according to claim 1, wherein the second interval does not overlap with the first interval.

9. A system according to claim 1, wherein the energy removal device includes a braking system or device.

10. A system according to claim 1, wherein the energy removal device directly controls the speed of the one or more elements constituting the robot arm.

11. A system according to claim 1, wherein the energy removal device directly controls the speed of the end effector.

12. A system according to claim 1, wherein the plan for using a combination of one or more motors and one or more energy removal devices to move one or more elements constituting the robot arm is determined without estimating the state of the robot system.

13. A system according to claim 1, wherein the plan for using a combination of one or more motors and one or more energy removal devices to move one or more elements constituting the robot arm is determined without estimating the state of the derivative of the robot system.

14. A system according to claim 1, wherein using one or more motors and one or more energy removal devices in combination to move one or more elements constituting the robot arm enables the end effector to move along the trajectory in a shorter time than would be required if only the one or more motors were used.

15. A system according to claim 1, wherein using one or more motors and one or more energy removal devices in combination to move one or more elements constituting the robot arm increases the throughput of the robot system compared to the throughput achieved when only the one or more motors are used.

16. A method for controlling a robotic system, The end effector that makes up the robot arm receives instructions for the trajectory it should move along. A plan is determined to use a combination of one or more motors and one or more energy removal devices different from the one or more motors to move one or more elements constituting the robot arm so that the end effector moves along the trajectory, the plan being to apply torque to one or more elements constituting the robot arm using one or more motors during a first interval, and to remove energy from one or more of the elements using one or more energy removal devices during a second interval that begins after the start of the first interval, Sending commands to execute the plan via a communication interface, A method that includes [a certain feature].

17. A method according to claim 16, wherein the commands for executing the plan include a first set of commands for causing the one or more motors to apply torque to the one or more elements constituting the robot arm during the first interval.

18. A method according to claim 17, wherein the first set of commands includes one or more commands transmitted to corresponding motor controllers via the communication interface.

19. A method according to claim 18, wherein the commands for carrying out the plan include a second set of commands for causing the one or more energy removal devices to remove energy from one or more of the elements during the second interval.

20. A computer program product, which is embodied in a non-temporary computer-readable medium, Computer commands for receiving instructions on the trajectory to which the end effector constituting the robot arm should move, A computer instruction for determining a plan to use a combination of one or more motors and one or more energy removal devices different from the one or more motors to move one or more elements constituting the robot arm so that the end effector moves along the trajectory, the plan comprising applying torque to one or more elements constituting the robot arm using one or more motors during a first interval, and removing energy from one or more of the elements using one or more energy removal devices during a second interval beginning after the start of the first interval, A computer instruction for sending a command to execute the plan via a communication interface, A computer program product that includes the following features.

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