The vast majority of work to date concerned with obstacle avoidance for manipulators has dealt with task descriptions in the form ofpick-and-place movements. The added flexibil ity in motion control for manipulators possessing redundant degrees offreedom permits the consideration of obstacle avoidance in the context of a specified end-effector trajectory as the task description. Such a task definition is a more accurate model for such tasks as spray painting or arc weld ing. The approach presented here is to determine the re quired joint angle rates for the manipulator under the con straints of multiple goals, the primary goal described by the specified end-effector trajectory and secondary goals describ ing the obstacle avoidance criteria. The decomposition of the solution into a particular and a homogeneous component effectively illustrates the priority of the multiple goals that is exact end-effector control with redundant degrees of freedom maximizing the distance to obstacles. An efficient numerical ...

/pdf/obstacle-avoidance-for-kinematically-redundant-manipulators-3fyn4yxbx0.pdf

Obstacle Avoidance for Kinematically Redundant Manipulators in Dynamically Varying Environments

In this paper, we describe a new scheme for redundancy control of robot manipulators. We introduce the concept of task priority in relation to the inverse kinematic problem of redundant robot manipulators. A required task is divided into subtasks according to the order of priority. We propose to determine the joint motions of robot manipulators so that subtasks with lower priority can be performed utilizing re dundancy on subtasks with higher priority. This procedure is formulated using the pseudoinverses of Jacobian matrices. Most problems of redundancy utilization can be formulated in the framework of tasks with the order of priority. The results of numerical simulations and experiments show the effectiveness of the proposed redundancy control scheme.

Task-priority based redundancy control of robot manipulators

Spacetime constraints are a new method for creating character animation. The animator specifies what the character has to do, for instance, "jump from here to there, clearing a hurdle in between;" how the motion should be performed, for instance "don't waste energy," or "come down hard enough to splatter whatever you land on;" the character's physical structure---the geometry, mass, connectivity, etc. of the parts; and the physical resources' available to the character to accomplish the motion, for instance the character's muscles, a floor to push off from, etc. The requirements contained in this description, together with Newton's laws, comprise a problem of constrained optimization. The solution to this problem is a physically valid motion satisfying the "what" constraints and optimizing the "how" criteria. We present as examples a Luxo lamp performing a variety of coordinated motions. These realistic motions conform to such principles of traditional animation as anticipation, squash-and-stretch, follow-through, and timing.

Spacetime constraints

1. Introduction and Historical Background 1.1 Why make human figure models? 1.2 Historical roots 1.3 What is currently possible? 1.4 Manipulation, animation, and simulation 1.5 What did we leave out? 2. Mody Modeling 2.1 Geometric body modeling 2.2 Representing articulated figures 2.3 A flexible torso model 2.4 Shoulder complex 2.5 Clothing models 2.6 The anthropometry database 2.7 The anthropometry spreadsheet 2.8 Strength and torque display 3. Spatial Interaction 3.1 Direct manipulation 3.2 Manipulation with constraints 3.3 Inverse kinematic positioning 4. Behavioral Control of Articulated Figures 4.1 An interactive system for postural control 4.2 Interactive manipulation with behaviors 4.3 The animation interface 4.4 Human figure motions 4.5 Virtual human control 5. Simulation with Societies of Behaviors 5.1 Forward simulation with behaviors 5.2 Locomotion 5.3 Strength guided motion 5.4 Collision-free path and motion planning 5.5 Posture planning 6. Task-level Specifications 6.1 Performance simulation with simple commands 6.2 Natural language expressions of kinematics and space 6.3 Task-level simulation 6.4 A framework for instruction understanding 7. Epilogue 7.1 A road map toward the future 7.2 Conclusion

/pdf/simulating-humans-computer-graphics-animation-and-control-2dk1fy50vu.pdf

Simulating humans: computer graphics animation and control

In this article, we attempt to reconcile the linguistic hypothesis that speech involves an underlying sequencing of abstract, discrete, context-independent units, with the empirical observation of continuous, context-dependent interleaving of articulatory movements. To this end, we first review a previously proposed task-dynamic model for the coordination and control of the speech articulators. We then describe an extension of this model in which invariant speech units (gestural primitives) are identified with context-independent sets of parameters in a dynamical system having two functionally distinct but interacting levels. The intergestural level is defined according to a set of activation coordinates; the interarticulator level is defined according to both model articulator and tractvariable coordinates. In the framework of this extended model, coproduction effects in speech are described in terms of the blending dynamics defined among a set of temporally overlapping active units; the relative timing ...

https://www.haskins.yale.edu/sr/SR099/SR099_03.pdf

A Dynamical Approach to Gestural Patterning in Speech Production

Kinematically redundant manipulators have a number of potential advantages over current manipulator designs. For this type of arm, velocity control through pseudoinverses is suggested. Questions associated with pseudoinverse control are examined in detail and show that in some cases this control leads to undesired arm configurations. A method for distributing joint angles of a redundant arm in a good approximation to a true minimax criterion is described. In addition several numerical considerations are discussed.

Review of pseudoinverse control for use with kinematically redundant manipulators

Abstract. In recent years, wearable devices such as smart bands and smartwatches have gained widespread popularity due to their ability to provide various health and fitness applications by detecting and analyzing the human body and motion information. However, the accuracy of location-based services can be limited, especially in urban areas and indoors. This study proposes a series of smartwatch Pedestrian Dead Reckoning (PDR) improvements based on 9 Degrees of Freedom (DOF) IMU orientation estimation, which includes the heading estimation of human movement and a novel pre-trained velocity regression model. The proposed system holds the potential to enhance positioning accuracy and augment navigation availability for smartwatch users, thus offering potential applications across various fields. This study makes significant contributions to the field of smartwatch navigation by proposing a GNSS/PDR fusion algorithm specifically designed for the consumer-grade IMU, magnetometer, and GNSS receiver built into Apple Watch, tracking varied roll and pitch of the sensor caused by hand swing, and integrating a CNN model to predict the 1-D speed and provide ZUPT information, offering improved accuracy and reliability.


A cnn-speed-based gnss/pdr integrated system for smartwatch

Abstract. The demand for navigation and positioning is increasing in various fields nowadays. Although Global Navigation Satellite Systems (GNSS) are currently the most widely used high-accuracy positioning method, their operation rests on signal transmission and reception, which is prone to interference from obstacles such as high-rise buildings, thereby limiting indoor navigation. In addition, in highly dynamic scenarios, the low update rate of the signal cannot track detailed motions. In this case, Inertial Measurement Units (IMUs) play an important role in serving as a complementary component. However, a single high-accuracy IMU is financially prohibitive. On the other hand, the lack of accuracy and stability limits the application of low-cost IMU in navigation. One way to improve the performance of low-cost IMU is to fuse multiple IMUs. This study focuses on the development of pedestrian navigation using multi-sensor integration of low-cost IMUs and magnetometers exploring different integration techniques to compare their performance. The Pedestrian Dead Reckoning (PDR) algorithm is a technique used to estimate the relative motion of pedestrian, which is a commonly used technology for indoor pedestrian navigation. This study use PDR with multi-sensor integration of low-cost IMUs to reduce the position error of pedestrian navigation to within one meter, with the aim of establishing a high-precision, reliable, and low-cost pedestrian navigation algorithm.


A multi-imu based self-contained pedestrian navigation algorithm

Abstract. Indoor positioning has gained increasing attention in previous decades. There are many wireless communication technologies replacing Global Navigation Satellite System (GNSS) because of the sheltered GNSS signal in indoor environment. Most of them need to set up external transceiver with high spatial density to get user's position, such as Wi-Fi, Ultra-Wideband (UWB), Bluetooth and so on. In order to reach high positioning accuracy, the cost of external transceiver becomes higher.This research focuses on low-cost pedestrian dead reckoning (PDR) without additional external equipment. Moreover, a magnetic fingerprint-based positioning is adopted to provide redundant observations of position and heading, using Extended Kalman Filter (EKF) to update the estimation. The proposed method reduces cumulative errors of PDR, achieving an improved algorithm. Since the geomagnetic field exists over the Earth, this technology doesn’t use external equipment either. The integration of PDR and magnetic fingerprint-based positioning, which only uses built-in sensors of a smartphone, should be a low-cost and wide coverage scheme.


/pdf/an-integrated-indoor-positioning-algorithm-for-smartphone-1rn5i68u.pdf

An integrated indoor positioning algorithm for smartphone using pedestrian dead reckoning with magnetic fingerprint aided

Abstract. Outdoor positioning requires a reliable solution that can work in environments where satellite signals are often blocked or degraded. Global Navigation Satellite System (GNSS) is a common choice, but it may not provide accurate results for land vehicles. To address this challenge, this research proposes a multi-sensor integrated system for vehicle navigation that combines GNSS with other sensors. The system uses Extended Kalman Filter (EKF) to fuse the data from different sources and improve the navigation performance. The algorithm targets to provide seamless navigation for urban environments as well as various indoor environments fields with INS/GNSS/VIO aiding integrated solutions. The experimental vehicle of this research is equipped with a tactical-grade inertial sensing measurement unit (IMU) as the test system, a self-designed and assembled visual platform, which includes a camera with a time synchronization protocol and a low-cost IMU. Also, both indoor experimental fields and outdoor urban scenarios with different high challenging were tested to verify the developed algorithm. To evaluate the performance of the proposed real-time navigation system, we use a high-accuracy navigation-grade system as a reference, which provides a stable and reliable trajectory. The result indicates that using the GNSS RTK solution with VIO aiding integration scheme reduced the RMS errors in long outage (450 sec, 1812 m) by 87.4% and 79.9% in position and velocity error, respectively. In urban scenario, the along-track/cross-track maximum errors can achieve 1.4 m / 1.5 m. Overall, these contribute to the development of real-time navigation systems for self-driving vehicle in the future.


https://doi.org/10.5194/isprs-archives-xlviii-1-w1-2023-609-2023

C.-H. Huang

Papers

Review of pseudoinverse control for use with kinematically redundant manipulators

A cnn-speed-based gnss/pdr integrated system for smartwatch

A multi-imu based self-contained pedestrian navigation algorithm

An integrated indoor positioning algorithm for smartphone using pedestrian dead reckoning with magnetic fingerprint aided

Seamless realtime lane level vehicular navigation in gnss challenging environments using a rtk gnss/imu/vins integration scheme