Karim Djouani | Université Paris-Est Créteil (original) (raw)
Papers by Karim Djouani
Electronics
With the availability of modern assistive techniques, ambient intelligence, and the Internet of T... more With the availability of modern assistive techniques, ambient intelligence, and the Internet of Things (IoT), various innovative assistive environments have been developed, such as driving assistance systems (DAS), where the human driver can be provided with physical and emotional assistance. In this human–machine collaboration system, haptic interaction interfaces are commonly employed because they provide drivers with a more manageable way to interact with other components. From the view of control system theory, this is a typical closed-loop feedback control system with a human in the loop. To make such a system work effectively, both the driving behaviour factors, and the electrical–mechanical components should be considered. However, the main challenge is how to deal with the high degree of uncertainties in human behaviour. This paper aims to provide an insightful overview of the relevant work. The impact of various types of haptic assistive driving systems (haptic guidance and...
Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access an... more Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access and route high volumes of traffic simultaneously. Such roles demand high network capacity, and long "online" time at the expense of accelerated transmission energy depletion and poor connectivity. This is the problem of transmission power control. Numerous power control methods for wireless networks are in literature. However, contributions towards MRMC configurations still face many challenges worth considering. In this paper, an energy-efficient power selection protocol called PMMUP is suggested at the Link-Layer. This protocol first divides the MRMC-WMN into a set of unified channel graphs (UCGs). A UCG consists of multiple radios interconnected to each other via a common wireless channel. In each UCG, a stochastic linear quadratic cost function is formulated. Each user minimizes this cost function consisting of trade-off between the size of unification states and the control ...
Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh netwo... more Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified Channel Graphs (UCGs). Second, each network interface card (NIC) or radio assigned to a unique UCG adjusts transmission power using predicted multiple interaction state variables (IV) across UCGs. Depending on the size of queue loads and intra- and inter-channel states, each NIC optimizes transmission power locally and asynchronously. A new power selection MRMC unification protocol (PMMUP) is proposed that coordinates interactions among radios. The efficacy of the proposed method is investigated through simulations.
Technologies, 2022
Visible light communications (VLC) is an emerging and promising concept that is capable of solvin... more Visible light communications (VLC) is an emerging and promising concept that is capable of solving the major challenges of 5G and Internet of Things (IoT) communication systems. Moreover, due to the usage of light-emitting diodes (LEDs) in almost every aspect of our daily life VLC is providing massive connectivity for various types of massive IoT communications ranging from machine-to-machine, vehicle-to-infrastructure, infrastructure-to-vehicle, chip-to-chip as well as device-to-device. In this paper, we undertake a comprehensive review of the prospects of implementing VLC for IoT. Moreover, we investigate existing and proposed approaches implemented in the application of VLC for IoT. Additionally, we look at the challenges faced in applying VLC for IoT and offer solutions where applicable. Then, we identify future research directions in the implementation of VLC for IoT.
In this paper we present a methodology for optimal force distribution calculation for the multipl... more In this paper we present a methodology for optimal force distribution calculation for the multiple manipulators system grasping an object.We consider for this case three robots holding a common rigid object with three contact points , where the object can translate and rotate in any directions. This approach is used in the case of real time dynamics object force control. The force distribution problem is formulated in terms of a nonlinear programming problem under equality and inequality constraints. Then, according to [1],[2],[3] and [4] the friction constraints are transformed from non linear inequalities into a combination of linear equalities and linear inequalities. The original non linear constrained programming problem is then transformed into a quadratic optimization problem. Some simulation results are given to show the efficiency and accuracy of the proposed methodology and perspectives on multiple manipulators system grasping an object control are discussed.
According to recent studies, billions of objects are expected to be connected wirelessly by 2020.... more According to recent studies, billions of objects are expected to be connected wirelessly by 2020. The Low Power Wide Area (LPWA) networks are already playing an important role in connecting billions of new devices making up the IoT. Long Range (LoRa) and Narrowband-IoT (NB-IoT) are currently the two leading technologies triggering considerable research interest. This paper focuses on providing a comprehensive and comparative survey study on the current research and industrial states of NB-IoT and LoRa in terms of their power efficiency, their capacity, quality of service (QoS), reliability and range of coverage. The outcome of this research survey demonstrates that the unlicensed LoRa is more advantageous than the NBIoT in terms of its energy efficiency, its capacity and cost while the NB-IoT gives benefits in terms of its reliability, resilience to interference, latency and QoS. It is further shown that despite the considerable research and development that has so far been carried ...
Robotics, 2021
Disabilities are a global issue due to the decrease in life quality and mobility of patients, esp... more Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human...
Robotics, 2021
The capabilities of collaborative robotics have transcended the conventional abilities of decentr... more The capabilities of collaborative robotics have transcended the conventional abilities of decentralised robots as it provides benefits such as scalability, flexibility and robustness. Collaborative robots can operate safely in complex human environments without being restricted by the safety cages or barriers that often accompany them. Collaborative robots can be used for various applications such as machine tending, packaging, process tasks and pick and place. This paper proposes an improvement of the current virtual impedance algorithm by developing an adaptive virtual impedance controlled mobile multi-robot system focused on dynamic obstacle avoidance with a controlled planar movement. The study includes the development of a mobile multi-robot platform whereby each robot plans a path individually without a supervisor. The proposed system would implement a two-layered hierarchy for robot path planning. The higher layer generates a trajectory from the current position to the desire...
Sensors, 2020
The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) ... more The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) technology for accommodating massive device connections in 5G and beyond. To enable network scalability, this study proposes a two-layers novel mixed approach that aims not only to create an efficient spectrum sharing among the many NB-IoT devices but also provides an energy-efficient network. On one layer, the approach uses an Adaptive Frequency Hopping Spread Spectrum (AFHSS) technique that uses a lightweight and secure pseudo-random sequence to exploit the channel diversity, to mitigate inter-link and cross-technology interference. On the second layer, the approach consists of a clustering and network coding (data aggregation) approach based on an energy-signal strength mixed gradient. The second layer contributes to offload the BS, allows for energy-efficient network scalability, helps balance the energy consumption of the network, and enhances the overall network lifetime. The propo...
Sensors, 2020
Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enh... more Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enhancing its network coverage. Many of the existing NB-IoT channel coding techniques are based on repeating transmission data and control signals as a way of enhancing the network’s reliability and therefore, enabling long-distance transmissions. Although most of these efforts are made at the expense of reducing the energy consumption of the NB-IoT network, they do not always consider the channel conditions. Therefore, this work proposes a novel NB-IoT Energy-Efficient Adaptive Channel Coding (EEACC) scheme. The EEACC approach is a two-dimensional (2D) approach which not only selects an appropriate channel coding scheme based on the estimated channel conditions (dynamically classified as bad, medium or good from initial based on a periodically assessed BLER performance outcome) but also minimizes the transmission repetition number under a pre-assessed probability of successful transmission...
International Journal on AdHoc Networking Systems, 2018
Computational and mathematical methods in medicine, 2018
Graph cut segmentation provides a platform to analyze images through a global segmentation strate... more Graph cut segmentation provides a platform to analyze images through a global segmentation strategy, and as a result of this, it has gained a wider acceptability in many interactive and automatic segmentation fields of application, such as the medical field. The graph cut energy function has a parameter that is tuned to ensure that the output is neither oversegmented (shrink bias) nor undersegmented. Models have been proposed in literature towards the improvement of graph cut segmentation, in the context of interactive and automatic cell segmentation. Along this line of research, the graph cut parameter has been leveraged, while in some instances, it has been ignored. Therefore, in this work, the relevance of graph cut parameter on both interactive and automatic cell segmentation is investigated. Statistical analysis, based on F1 score, of three publicly available datasets of cells, suggests that the graph cut parameter plays a significant role in improving the segmentation accuracy...
2015 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2015
The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to t... more The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to the important mobility ease they provide to people with disability. Nonetheless, users with extreme mobility impairments still experience some cognitive and physical steering challenges that limit their capacity to navigate even simple environments. Assistive wheelchairs with functionalities to enable customisation of user handicap are therefore still required. The diversity of user disabilities and needs, and the corresponding assistive measures, necessitate proper understanding of the user. Modelling and integration of user driving behaviour into the control loop in order to monitor user inputs, and execute necessary corrective steps in troublesome situations, may just be one way of providing the assistance that corresponds to needs of the user. This paper attempts to identify the steering behaviour of an individual wheelchair user in a normal living room environment. The preliminary navigation experiments required to obtain the steering data are performed in a virtual world on an augmented wheelchair platform, and the participant is observed to exhibit expected navigational behaviours. Least square method is considered in the estimation of model parameters for the non-linear steering model with interesting regression analysis outcome.
International Journal of Applied Mathematics and Computer Science, 2012
Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations d... more Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations do experience power control problems such as the inter-channel and co-channel interference, high energy consumption at multiple queues and unscalable network connectivity. Such network problems can be conveniently modelled using the theory of queue perturbation in the multiple queue systems and also as a weak coupling in a multiple channel wireless network. Consequently, this paper proposes a queue perturbation and weakly coupled based power control approach forWBNs. The ultimate objectives are to increase energy efficiency and the overall network capacity. In order to achieve this objective, a Markov chain model is first presented to describe the behaviour of the steady state probability distribution of the queue energy and buffer states. The singular perturbation parameter is approximated from the coefficients of the Taylor series expansion of the probability distribution. The impact of...
Electronics
With the availability of modern assistive techniques, ambient intelligence, and the Internet of T... more With the availability of modern assistive techniques, ambient intelligence, and the Internet of Things (IoT), various innovative assistive environments have been developed, such as driving assistance systems (DAS), where the human driver can be provided with physical and emotional assistance. In this human–machine collaboration system, haptic interaction interfaces are commonly employed because they provide drivers with a more manageable way to interact with other components. From the view of control system theory, this is a typical closed-loop feedback control system with a human in the loop. To make such a system work effectively, both the driving behaviour factors, and the electrical–mechanical components should be considered. However, the main challenge is how to deal with the high degree of uncertainties in human behaviour. This paper aims to provide an insightful overview of the relevant work. The impact of various types of haptic assistive driving systems (haptic guidance and...
Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access an... more Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access and route high volumes of traffic simultaneously. Such roles demand high network capacity, and long "online" time at the expense of accelerated transmission energy depletion and poor connectivity. This is the problem of transmission power control. Numerous power control methods for wireless networks are in literature. However, contributions towards MRMC configurations still face many challenges worth considering. In this paper, an energy-efficient power selection protocol called PMMUP is suggested at the Link-Layer. This protocol first divides the MRMC-WMN into a set of unified channel graphs (UCGs). A UCG consists of multiple radios interconnected to each other via a common wireless channel. In each UCG, a stochastic linear quadratic cost function is formulated. Each user minimizes this cost function consisting of trade-off between the size of unification states and the control ...
Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh netwo... more Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified Channel Graphs (UCGs). Second, each network interface card (NIC) or radio assigned to a unique UCG adjusts transmission power using predicted multiple interaction state variables (IV) across UCGs. Depending on the size of queue loads and intra- and inter-channel states, each NIC optimizes transmission power locally and asynchronously. A new power selection MRMC unification protocol (PMMUP) is proposed that coordinates interactions among radios. The efficacy of the proposed method is investigated through simulations.
Technologies, 2022
Visible light communications (VLC) is an emerging and promising concept that is capable of solvin... more Visible light communications (VLC) is an emerging and promising concept that is capable of solving the major challenges of 5G and Internet of Things (IoT) communication systems. Moreover, due to the usage of light-emitting diodes (LEDs) in almost every aspect of our daily life VLC is providing massive connectivity for various types of massive IoT communications ranging from machine-to-machine, vehicle-to-infrastructure, infrastructure-to-vehicle, chip-to-chip as well as device-to-device. In this paper, we undertake a comprehensive review of the prospects of implementing VLC for IoT. Moreover, we investigate existing and proposed approaches implemented in the application of VLC for IoT. Additionally, we look at the challenges faced in applying VLC for IoT and offer solutions where applicable. Then, we identify future research directions in the implementation of VLC for IoT.
In this paper we present a methodology for optimal force distribution calculation for the multipl... more In this paper we present a methodology for optimal force distribution calculation for the multiple manipulators system grasping an object.We consider for this case three robots holding a common rigid object with three contact points , where the object can translate and rotate in any directions. This approach is used in the case of real time dynamics object force control. The force distribution problem is formulated in terms of a nonlinear programming problem under equality and inequality constraints. Then, according to [1],[2],[3] and [4] the friction constraints are transformed from non linear inequalities into a combination of linear equalities and linear inequalities. The original non linear constrained programming problem is then transformed into a quadratic optimization problem. Some simulation results are given to show the efficiency and accuracy of the proposed methodology and perspectives on multiple manipulators system grasping an object control are discussed.
According to recent studies, billions of objects are expected to be connected wirelessly by 2020.... more According to recent studies, billions of objects are expected to be connected wirelessly by 2020. The Low Power Wide Area (LPWA) networks are already playing an important role in connecting billions of new devices making up the IoT. Long Range (LoRa) and Narrowband-IoT (NB-IoT) are currently the two leading technologies triggering considerable research interest. This paper focuses on providing a comprehensive and comparative survey study on the current research and industrial states of NB-IoT and LoRa in terms of their power efficiency, their capacity, quality of service (QoS), reliability and range of coverage. The outcome of this research survey demonstrates that the unlicensed LoRa is more advantageous than the NBIoT in terms of its energy efficiency, its capacity and cost while the NB-IoT gives benefits in terms of its reliability, resilience to interference, latency and QoS. It is further shown that despite the considerable research and development that has so far been carried ...
Robotics, 2021
Disabilities are a global issue due to the decrease in life quality and mobility of patients, esp... more Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human...
Robotics, 2021
The capabilities of collaborative robotics have transcended the conventional abilities of decentr... more The capabilities of collaborative robotics have transcended the conventional abilities of decentralised robots as it provides benefits such as scalability, flexibility and robustness. Collaborative robots can operate safely in complex human environments without being restricted by the safety cages or barriers that often accompany them. Collaborative robots can be used for various applications such as machine tending, packaging, process tasks and pick and place. This paper proposes an improvement of the current virtual impedance algorithm by developing an adaptive virtual impedance controlled mobile multi-robot system focused on dynamic obstacle avoidance with a controlled planar movement. The study includes the development of a mobile multi-robot platform whereby each robot plans a path individually without a supervisor. The proposed system would implement a two-layered hierarchy for robot path planning. The higher layer generates a trajectory from the current position to the desire...
Sensors, 2020
The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) ... more The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) technology for accommodating massive device connections in 5G and beyond. To enable network scalability, this study proposes a two-layers novel mixed approach that aims not only to create an efficient spectrum sharing among the many NB-IoT devices but also provides an energy-efficient network. On one layer, the approach uses an Adaptive Frequency Hopping Spread Spectrum (AFHSS) technique that uses a lightweight and secure pseudo-random sequence to exploit the channel diversity, to mitigate inter-link and cross-technology interference. On the second layer, the approach consists of a clustering and network coding (data aggregation) approach based on an energy-signal strength mixed gradient. The second layer contributes to offload the BS, allows for energy-efficient network scalability, helps balance the energy consumption of the network, and enhances the overall network lifetime. The propo...
Sensors, 2020
Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enh... more Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enhancing its network coverage. Many of the existing NB-IoT channel coding techniques are based on repeating transmission data and control signals as a way of enhancing the network’s reliability and therefore, enabling long-distance transmissions. Although most of these efforts are made at the expense of reducing the energy consumption of the NB-IoT network, they do not always consider the channel conditions. Therefore, this work proposes a novel NB-IoT Energy-Efficient Adaptive Channel Coding (EEACC) scheme. The EEACC approach is a two-dimensional (2D) approach which not only selects an appropriate channel coding scheme based on the estimated channel conditions (dynamically classified as bad, medium or good from initial based on a periodically assessed BLER performance outcome) but also minimizes the transmission repetition number under a pre-assessed probability of successful transmission...
International Journal on AdHoc Networking Systems, 2018
Computational and mathematical methods in medicine, 2018
Graph cut segmentation provides a platform to analyze images through a global segmentation strate... more Graph cut segmentation provides a platform to analyze images through a global segmentation strategy, and as a result of this, it has gained a wider acceptability in many interactive and automatic segmentation fields of application, such as the medical field. The graph cut energy function has a parameter that is tuned to ensure that the output is neither oversegmented (shrink bias) nor undersegmented. Models have been proposed in literature towards the improvement of graph cut segmentation, in the context of interactive and automatic cell segmentation. Along this line of research, the graph cut parameter has been leveraged, while in some instances, it has been ignored. Therefore, in this work, the relevance of graph cut parameter on both interactive and automatic cell segmentation is investigated. Statistical analysis, based on F1 score, of three publicly available datasets of cells, suggests that the graph cut parameter plays a significant role in improving the segmentation accuracy...
2015 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2015
The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to t... more The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to the important mobility ease they provide to people with disability. Nonetheless, users with extreme mobility impairments still experience some cognitive and physical steering challenges that limit their capacity to navigate even simple environments. Assistive wheelchairs with functionalities to enable customisation of user handicap are therefore still required. The diversity of user disabilities and needs, and the corresponding assistive measures, necessitate proper understanding of the user. Modelling and integration of user driving behaviour into the control loop in order to monitor user inputs, and execute necessary corrective steps in troublesome situations, may just be one way of providing the assistance that corresponds to needs of the user. This paper attempts to identify the steering behaviour of an individual wheelchair user in a normal living room environment. The preliminary navigation experiments required to obtain the steering data are performed in a virtual world on an augmented wheelchair platform, and the participant is observed to exhibit expected navigational behaviours. Least square method is considered in the estimation of model parameters for the non-linear steering model with interesting regression analysis outcome.
International Journal of Applied Mathematics and Computer Science, 2012
Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations d... more Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations do experience power control problems such as the inter-channel and co-channel interference, high energy consumption at multiple queues and unscalable network connectivity. Such network problems can be conveniently modelled using the theory of queue perturbation in the multiple queue systems and also as a weak coupling in a multiple channel wireless network. Consequently, this paper proposes a queue perturbation and weakly coupled based power control approach forWBNs. The ultimate objectives are to increase energy efficiency and the overall network capacity. In order to achieve this objective, a Markov chain model is first presented to describe the behaviour of the steady state probability distribution of the queue energy and buffer states. The singular perturbation parameter is approximated from the coefficients of the Taylor series expansion of the probability distribution. The impact of...