Objective:To analyze the effects of repetitive transcranial magnetic stimulation combined with motor control training on the treatment of stroke-induced hemiplegia,specifically focusing on the impact on patients’bala...Objective:To analyze the effects of repetitive transcranial magnetic stimulation combined with motor control training on the treatment of stroke-induced hemiplegia,specifically focusing on the impact on patients’balance function and gait.Methods:Fifty-two cases of hemiplegic stroke patients were randomly divided into two groups,26 in the control group and 26 in the observation group,using computer-generated random grouping.All participants underwent conventional treatment and rehabilitation training.In addition to these,the control group received repetitive transcranial magnetic pseudo-stimulation therapy+motor control training,while the observation group received repetitive transcranial magnetic stimulation therapy+motor control training.The balance function and gait parameters of both groups were compared before and after the interventions and assessed the satisfaction of the interventions in both groups.Results:Before the invention,there were no significant differences in balance function scores and each gait parameter between the two groups(P>0.05).However,after the intervention,the observation group showed higher balance function scores compared to the control group(P<0.05).The observation group also exhibited higher step speed and step frequency,longer step length,and a higher overall satisfaction level with the intervention compared to the control group(P<0.05).Conclusion:The combination of repetitive transcranial magnetic stimulation and motor control training in the treatment of stroke-induced hemiplegia has demonstrated positive effects.It not only improves the patient’s balance function and gait but also contributes to overall physical rehabilitation.展开更多
This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that at...This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts.A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk.Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task.Motor control is inclusive of motor planning and motor learning.If sensory information is not accurately perceived or there is interference with sensory information processing and cognition,motor function will be altered,and an athlete may become vulnerable to injury during sport participation.Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria,including a normal neurological examination,resolution of symptoms,and return to baseline function on traditional concussion testing.In conjunction,altered motor function is demonstrated after SRC in muscle activation and force production,movement patterns,balance/postural stability,and motor task performance,especially performance of a motor task paired with a cognitive task(i.e.,dual-task condition).The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.展开更多
In order to improve the heat dissipation capability of motor controller for new energy vehicles,the water cooled radiator with multiple channels is optimized in this paper.The heat conduction between the heat source I...In order to improve the heat dissipation capability of motor controller for new energy vehicles,the water cooled radiator with multiple channels is optimized in this paper.The heat conduction between the heat source IGBT and the radiator,the convective heat transfer between the radiator and the coolant,the mechanical strength and the manufacturing cost are comprehensively considered during the optimization process.The power loss and thermal resistance of the IGBT unit are calculated at first,and finite element model of the radiator is established.On this basis,multi-physics coupling analysis of the water cooled radiator is carried out.Secondly,the sensitivity analysis is applied to verify the influence of structural parameters on the heat dissipation performance of the radiator system.The influence of coolant inlet velocity v,number of cooling ribs n,height of radiator ribs H on the maximum temperature rise T,the temperature difference ΔT between phase U and W,and the coolant pressure lossΔP are analyzed in depth,and the optimal range of the structural parameters for heat dissipation is obtained.Finally,an experimental platform was set up to verify the performance of the proposed structure of water cooled radiator for motor controller of new energy vehicle.The results show that the heat dissipation capability of the proposed radiator is improved compared with the initial design.展开更多
Background: In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompas...Background: In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompassing disciplines such as biomechanics, motor control and learning, exercise physiology, sports medicine, sport psychology to name a few. Rarely are these disciplines applied in an integrated manner. The purpose of this study was to document the effectiveness of an integrated biomechanics and motor control protocol for improving athlete's performance in the high jump. Methods: Four elite high jumpers performed baseline jumps under no^mal conditions and then jumps using a specific external focus of attention cue designed to improve their running posture. Three-dimensional biomeehanical analysis was used to quantify the upright posture throughout the approach as well as horizontal velocity at plant and vertical velocity at takeoff. Results: The results showed that when using the external focus of attention cue, the jumpers were significantly more upright during the approach, had significantly higher horizontal velocities at plant, and generated significantly greater vertical velocities during the takeoff. Conclusion: The results of this study lay the foundation for future work examining how integrating sport science disciplines can improve performance of elite level athletes.展开更多
The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an i...The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an improved electrical measurement method for the motor controller efficiency is proposed in this paper,which is established by analyzing the power loss distribution and phase currents of the motor controller.It is demonstrated that the SiC MOSFET chips are the main power loss devices in the motor controller,accounting for more than 93.1%of the total power loss.The accuracy of the proposed method is compared with the traditional method in simulation.It shows that the test error of the efficiency obtained by the traditional method fluctuates on a large scale,which varied from 0.094%to 1.911%.Compared with the traditional method,the test error of the proposed method appears to be less than 0.083%,which provides significant guidance for the motor controller efficiency test and design.展开更多
Objective of the study: This study aimed at characterizing output features of the higher-order motor control centers (hoMCCs), including secondary (premotor cortex [Pre] and supplementary motor area [SMA]) and associa...Objective of the study: This study aimed at characterizing output features of the higher-order motor control centers (hoMCCs), including secondary (premotor cortex [Pre] and supplementary motor area [SMA]) and association (prefrontal cortex [PFC]) motor regions to the primary motor cortex (M1) during graded force tasks. It is well known that one of the major roles of the primary motor cortex (M1) is controlling motor output such as muscle force. However, it is unclear how the hoMCCs interact with M1 in regulating voluntary muscle contractions. Methods: fMRI data was acquired during graded force tasks and fMRI-based effective connectivity (EC) and muscle force analyses were performed to study the relationship between hoMCCs-M1 effective connectivity and voluntarily exerted handgrip force. Results: The results show that there is a consistent information flow from the hoMCCs to M1 under all force conditions, suggesting a hierarchical control mechanism in the brain in regulating voluntary muscle force. Only the premotor cortex exhibited a significant role in mediating the level of force production through its EC with M1 but that role diminished when the exerted force was high, suggesting perhaps a ceiling and/or fatigue effect on the EC. A flip in the direction of EC from the primary sensory cortex (S1) to the hoMCCs (PFC, SMA, and Pre) at lower force levels while at higher forces EC was observed from the hoMCCs to S1. Conclusion: The hoMCCs regulate M1 output to produce desired voluntary muscle force. Only the Pre-to-M1 connectivity strength directly correlates with the force level especially from low to moderate levels. The hoMCCs are involved in modulating higher force production likely by strengthening M1 output and downgrad<span style="font-size:12px;line-height:102%;font-family:Verdana;">ing</span><span style="font-size:12px;line-height:102%;font-family:Verdana;"> inhibition from S1 to M1.</span>展开更多
Background: Work related low back pain has been identified as a one of the most costly disorders among the worldwide working population. This condition was highly prevalent that approximately 85% patients having back ...Background: Work related low back pain has been identified as a one of the most costly disorders among the worldwide working population. This condition was highly prevalent that approximately 85% patients having back pain were brought on by prolonged sitting. With the rapid development of modern technology, sitting has now become the most common posture in today’s work- place. Idea of using motor control learning approach provides the optimal control and coordination of the spine. The McKenzie evaluation was received using repeated movements and sustained positions. Therefore high quality randomized clinical trial was required to compare the effectiveness of these treatments for work related low back pain. Objectives: To compare the effectiveness of motor control exercises and McKenzie exercises in reducing pain and disability in work related low back pain. Method: The study included 40 subjects with work related low back pain due to prolonged sitting. They were randomly allocated into two groups (Group A and Group B). Group A was treated with motor control exercises and group B was treated with McKenzie exercises for 4 weeks. Results: Both the groups have shown statically significant improvement in vas with p < 0.0001 and ODI with p < 0.0001. When the comparison was done after the 4 weeks, the percentage of improvement in group A was much higher than Group B. Conclusion: The study concluded that motor control exercises have shown statically and clinically significant improvement in reducing pain and disability when compared to McKenzie exercises among work related low back pain subjects.展开更多
A new control scheme for induction motors is proposed in the present paper, applying the interconnection and damping assignment-passivity based control (IDA-PBC) method. The scheme is based exclusively on passivity ...A new control scheme for induction motors is proposed in the present paper, applying the interconnection and damping assignment-passivity based control (IDA-PBC) method. The scheme is based exclusively on passivity based control, without restricting the input frequency as it is done in field oriented control (FOC). A port-controlled Hamiltonian (PCH) model of the induction motor is deduced to make the interconnection and damping of energy explicit on the scheme. The proposed controller is validated under computational simulations and experimental tests using an inverter prototype.展开更多
In the context of induction motor control, there are various control strategies used to separately control torque and flux. One common approach is known as Field-Oriented Control (FOC). This technique involves transfo...In the context of induction motor control, there are various control strategies used to separately control torque and flux. One common approach is known as Field-Oriented Control (FOC). This technique involves transforming the three-phase currents and voltages into a rotating reference frame, commonly referred to as the “dq” frame. In this frame, the torque/speed and flux components are decoupled, allowing for independent control, by doing so, the motor’s speed can be regulated accurately and maintain a constant flux which is crucial to ensure optimal motor performance and efficiency. The research focused on studying and simulating a field-oriented control system using fuzzy control techniques for an induction motor. The aim was to address the issue of parameter variations, particularly the change in rotor resistance during motor operation, which causes the control system to deviate from the desired direction. This deviation implies to an increase in the magnetic flux value, specifically the flux component on the q-axis. By employing fuzzy logic techniques to regulate flux vector’s components in the dq frame, this problem was successfully resolved, ensuring that the magnetic flux value remains within the nominal limits. To enhance the control system’s performance, response speed, and efficiency of the motor, sliding mode controllers were implemented to regulate the current in the inner loop. The simulation results demonstrated the proficiency of the proposed methodology.展开更多
The automation process is a very important pillar for Industry 4.0.One of the first steps is the control of motors to improve production efficiency and generate energy savings.In mass production industries,techniques ...The automation process is a very important pillar for Industry 4.0.One of the first steps is the control of motors to improve production efficiency and generate energy savings.In mass production industries,techniques such as digital signal processing(DSP)systems are implemented to control motors.These systems are efficient but very expensive for certain applications.From this arises the need for a controller capable of handling AC and DC motors that improves efficiency and maintains low energy consumption.This project presents the design of an adaptive control system for brushless AC induction and DC motors,which is functional to any type of plant in the industry.The design was possible by implementing Matlab software and tools such as digital signal processor(DSP)and Simulink.Through an extensive investigation of the state of the art,three models needed to represent the control system have been specified.The first model for the AC motor,the second for the DC motor and the third for the DSP control;this is done in this way so that the probability of failure is lower.Subsequently,these models have been programmed in Simulink,integrating the three main models into one.In this way,the design of a controller for use in AC induction motors,specifically squirrel cage and brushless DC motors,has been achieved.The final model represents a response time of 0.25 seconds,which is optimal for this type of application,where response times of 2e-3 to 3 seconds are expected.展开更多
The complex working conditions and nonlinear characteristics of the motor drive control system of industrial robots make it difficult to detect faults.In this paper,a deep learning-based observer,which combines the co...The complex working conditions and nonlinear characteristics of the motor drive control system of industrial robots make it difficult to detect faults.In this paper,a deep learning-based observer,which combines the convolutional neural network(CNN)and the long short-term memory network(LSTM),is employed to approximate the nonlinear driving control system.CNN layers are introduced to extract dynamic features of the data,whereas LSTM layers perform time-sequential prediction of the target system.In terms of application,normal samples are fed into the observer to build an offline prediction model for the target system.The trained CNN-LSTM-based observer is then deployed along with the target system to estimate the system outputs.Online fault detection can be realized by analyzing the residuals.Finally,an application of the proposed fault detection method to a brushless DC motor drive system is given to verify the effectiveness of the proposed scheme.Simulation results indicate the impressive fault detection capability of the presented method for driving control systems of industrial robots.展开更多
Spinal cord injury (SCI) is a major cause of disability. A serious consequence of SCI is the loss or partialloss of motor control. A number of therapies are currently being developed for restoring motor function in ...Spinal cord injury (SCI) is a major cause of disability. A serious consequence of SCI is the loss or partialloss of motor control. A number of therapies are currently being developed for restoring motor function in SCI patients. However, such approaches generally require intact neural motor systems for driving limb movements. There is evidence that SCI can generate such conditions in the brain,展开更多
This article introduces the control principle,technical status and two commonly used motor control schemes of permanent magnet synchronous motors for new energy vehicles.Direct torque control is selected as the resear...This article introduces the control principle,technical status and two commonly used motor control schemes of permanent magnet synchronous motors for new energy vehicles.Direct torque control is selected as the research object,and its advantages and disadvantages with vector control are analyzed.A Simulink simulation model was established according to the control principle.展开更多
Aim:The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury(SCI)post intensive whole-body training vs.upper body training with brain motor control assessment(BMCA).Me...Aim:The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury(SCI)post intensive whole-body training vs.upper body training with brain motor control assessment(BMCA).Methods:Twelve neurologically intact participants and 18 patients with SCI participated in this study as part of a multi-centre randomised controlled trial.All participants received 12 weeks training(three times per week),which comprised trunk,upper and lower limb exercises and locomotor training and functional electrical stimulation-assisted cycling in whole-body training group and an upper body strength and fitness program for upper body training group.Results:Generalised linear model analysis showed significant effect of the main effect of the Task(P<0.001)on the similarity index of voluntary movement patterns but not on the other factors or the interactions between them(P>0.05).Some participants showed significant improvement in muscle strength post 12 weeks training;however,this improvement was not reflected in the pattern of muscle activation which was captured by BMCA.Conclusion:BMCA is a valuable objective assessment tool that could add resolution to the clinical evaluation of patients with SCI post different therapeutic techniques.展开更多
The article is designed hardware platform of TMS320F2812 primary control chip based on the motor drive controller outputs and input signal, the use of DSP technology, together with the corresponding peripheral driver ...The article is designed hardware platform of TMS320F2812 primary control chip based on the motor drive controller outputs and input signal, the use of DSP technology, together with the corresponding peripheral driver circuit, a signal processing circuit and other processing module, the design and realize a piece of printed circuit board to achieve the required functionality. Systems software modules is implement hardware configuration and achieve control strategies in the DSP CCS compiler environment and using C and assembly language. Through CAN controller that comes with the DSP programming, achieved its CAN signal transmission and reception.展开更多
DTC (direct torque control) of induction motor drives has many outstanding performance and implementation properties. This paper presents an innovative direct torque controlled load generator based on space vector m...DTC (direct torque control) of induction motor drives has many outstanding performance and implementation properties. This paper presents an innovative direct torque controlled load generator based on space vector modulation suitable for the emerging applications such as electrical test benches that require extremely fast large-signal torque and dynamic responses. To realize system performance, two methods based on the classical DTC (with six-sector switch table) and the proposed twelve-sector DTC have been analyzed and used for modelling the dynamometer. The performance of the proposed dynamometer is investigated by simulating different parts of the system and results are presented for several industrial load profiles. Finally, limitations and advantages of each controller are presented and analyzed.展开更多
This paper describes the incremental PID control algorithm and the basic principles of motor soft start, and introduced STM32F103RB8 basic performance microcontroller, combined with incremental PID control advantages,...This paper describes the incremental PID control algorithm and the basic principles of motor soft start, and introduced STM32F103RB8 basic performance microcontroller, combined with incremental PID control advantages, and gives MCU in motor soft start process control application. Practice shows that the incremental PID applications, simplifying the control ideas to improve the performance of the current loop control, limiting the starting current, smooth start-up speed, and achieved good results motor start.展开更多
Therapeutic intervention for spinal cord injury is limited,with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training.As compared with learning novel com...Therapeutic intervention for spinal cord injury is limited,with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training.As compared with learning novel compensatory strategies,rehabilitation focuses on resto ring movements lost to injury.Whether rehabilitation of previously learned movements after spinal cord injury requires the molecular mechanisms of motor learning,or if it engages previously trained motor circuits without requiring novel learning remains an open question.In this study,mice we re randomly assigned to receive intrape ritoneal injection with the pan-nicotinic,non-competitive antagonist mecamylamine and the nicotinicα7 subunit selective antagonist methyllycaconitine citrate salt or vehicle(normal saline)prior to motor learning assays,then randomly reassigned after motor learning for rehabilitation study post-injury.Ce rvical spinal co rd dorsal column lesion was used as a model of in complete injury.Results of this study showed that nicotinic acetylcholine signaling was required for motor learning of the single pellet-reaching task but it was dispensable for the rehabilitation of the same task after injury.Our findings indicate that critical diffe rences exist between the molecular mechanisms supporting compensatory motor learning strategies and the restoration of behavior lost to spinal cord injury.展开更多
The bearingless induction motor, which combines the inductionmotor and magnetic bearing is a strongly coupled complicatednonlinear system; the decoupling control of the electromag- net toqueand readial levitation forc...The bearingless induction motor, which combines the inductionmotor and magnetic bearing is a strongly coupled complicatednonlinear system; the decoupling control of the electromag- net toqueand readial levitation force is the base of the stable operation ofthe benaringless motor. In this paper, the air-gap motor fluxoriented vector control is proposed to realize the decoupling controlof this nonlinear system even in the transient case based on thelevitation principle. Simulations show the stable suspension and goodperformance of the proposed algorithm.展开更多
Pump controlled motor electrohydraulic servo systems are much used in circumstances where high power drive is needed. This kind of system has the advantage of energy-saving. But, it also has some defects that have to ...Pump controlled motor electrohydraulic servo systems are much used in circumstances where high power drive is needed. This kind of system has the advantage of energy-saving. But, it also has some defects that have to be improved. Microcomputer control of a pump controlled motor electrohydraulic servo system is studied. A PID controller is first adopted on the closed loop control system, and experimental results are obtained. Then, a model reference adaptive controller is designed and realised on the same system applying a single board microcomputer. Experimental results show that the dynamic properties of the adaptive control system is much better than those of the PID system under different inertia load conditions.展开更多
文摘Objective:To analyze the effects of repetitive transcranial magnetic stimulation combined with motor control training on the treatment of stroke-induced hemiplegia,specifically focusing on the impact on patients’balance function and gait.Methods:Fifty-two cases of hemiplegic stroke patients were randomly divided into two groups,26 in the control group and 26 in the observation group,using computer-generated random grouping.All participants underwent conventional treatment and rehabilitation training.In addition to these,the control group received repetitive transcranial magnetic pseudo-stimulation therapy+motor control training,while the observation group received repetitive transcranial magnetic stimulation therapy+motor control training.The balance function and gait parameters of both groups were compared before and after the interventions and assessed the satisfaction of the interventions in both groups.Results:Before the invention,there were no significant differences in balance function scores and each gait parameter between the two groups(P>0.05).However,after the intervention,the observation group showed higher balance function scores compared to the control group(P<0.05).The observation group also exhibited higher step speed and step frequency,longer step length,and a higher overall satisfaction level with the intervention compared to the control group(P<0.05).Conclusion:The combination of repetitive transcranial magnetic stimulation and motor control training in the treatment of stroke-induced hemiplegia has demonstrated positive effects.It not only improves the patient’s balance function and gait but also contributes to overall physical rehabilitation.
文摘This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts.A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk.Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task.Motor control is inclusive of motor planning and motor learning.If sensory information is not accurately perceived or there is interference with sensory information processing and cognition,motor function will be altered,and an athlete may become vulnerable to injury during sport participation.Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria,including a normal neurological examination,resolution of symptoms,and return to baseline function on traditional concussion testing.In conjunction,altered motor function is demonstrated after SRC in muscle activation and force production,movement patterns,balance/postural stability,and motor task performance,especially performance of a motor task paired with a cognitive task(i.e.,dual-task condition).The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.
基金supported in part by the National Natural Science Foundation of China(61503132)。
文摘In order to improve the heat dissipation capability of motor controller for new energy vehicles,the water cooled radiator with multiple channels is optimized in this paper.The heat conduction between the heat source IGBT and the radiator,the convective heat transfer between the radiator and the coolant,the mechanical strength and the manufacturing cost are comprehensively considered during the optimization process.The power loss and thermal resistance of the IGBT unit are calculated at first,and finite element model of the radiator is established.On this basis,multi-physics coupling analysis of the water cooled radiator is carried out.Secondly,the sensitivity analysis is applied to verify the influence of structural parameters on the heat dissipation performance of the radiator system.The influence of coolant inlet velocity v,number of cooling ribs n,height of radiator ribs H on the maximum temperature rise T,the temperature difference ΔT between phase U and W,and the coolant pressure lossΔP are analyzed in depth,and the optimal range of the structural parameters for heat dissipation is obtained.Finally,an experimental platform was set up to verify the performance of the proposed structure of water cooled radiator for motor controller of new energy vehicle.The results show that the heat dissipation capability of the proposed radiator is improved compared with the initial design.
文摘Background: In recent years, there has been a proliferation of technology and sport science utilized within an athlete's training, especially at the elite level. However, the sport science is a broad field, encompassing disciplines such as biomechanics, motor control and learning, exercise physiology, sports medicine, sport psychology to name a few. Rarely are these disciplines applied in an integrated manner. The purpose of this study was to document the effectiveness of an integrated biomechanics and motor control protocol for improving athlete's performance in the high jump. Methods: Four elite high jumpers performed baseline jumps under no^mal conditions and then jumps using a specific external focus of attention cue designed to improve their running posture. Three-dimensional biomeehanical analysis was used to quantify the upright posture throughout the approach as well as horizontal velocity at plant and vertical velocity at takeoff. Results: The results showed that when using the external focus of attention cue, the jumpers were significantly more upright during the approach, had significantly higher horizontal velocities at plant, and generated significantly greater vertical velocities during the takeoff. Conclusion: The results of this study lay the foundation for future work examining how integrating sport science disciplines can improve performance of elite level athletes.
基金Supported by National Key Research and Development Program of China(2016YFB0100605)。
文摘The traditional measurement method was inaccurate to evaluate the motor controller efficiency,which the measurement efficiency value could be more than 100%in practical testing experiments.To deal with this issue,an improved electrical measurement method for the motor controller efficiency is proposed in this paper,which is established by analyzing the power loss distribution and phase currents of the motor controller.It is demonstrated that the SiC MOSFET chips are the main power loss devices in the motor controller,accounting for more than 93.1%of the total power loss.The accuracy of the proposed method is compared with the traditional method in simulation.It shows that the test error of the efficiency obtained by the traditional method fluctuates on a large scale,which varied from 0.094%to 1.911%.Compared with the traditional method,the test error of the proposed method appears to be less than 0.083%,which provides significant guidance for the motor controller efficiency test and design.
文摘Objective of the study: This study aimed at characterizing output features of the higher-order motor control centers (hoMCCs), including secondary (premotor cortex [Pre] and supplementary motor area [SMA]) and association (prefrontal cortex [PFC]) motor regions to the primary motor cortex (M1) during graded force tasks. It is well known that one of the major roles of the primary motor cortex (M1) is controlling motor output such as muscle force. However, it is unclear how the hoMCCs interact with M1 in regulating voluntary muscle contractions. Methods: fMRI data was acquired during graded force tasks and fMRI-based effective connectivity (EC) and muscle force analyses were performed to study the relationship between hoMCCs-M1 effective connectivity and voluntarily exerted handgrip force. Results: The results show that there is a consistent information flow from the hoMCCs to M1 under all force conditions, suggesting a hierarchical control mechanism in the brain in regulating voluntary muscle force. Only the premotor cortex exhibited a significant role in mediating the level of force production through its EC with M1 but that role diminished when the exerted force was high, suggesting perhaps a ceiling and/or fatigue effect on the EC. A flip in the direction of EC from the primary sensory cortex (S1) to the hoMCCs (PFC, SMA, and Pre) at lower force levels while at higher forces EC was observed from the hoMCCs to S1. Conclusion: The hoMCCs regulate M1 output to produce desired voluntary muscle force. Only the Pre-to-M1 connectivity strength directly correlates with the force level especially from low to moderate levels. The hoMCCs are involved in modulating higher force production likely by strengthening M1 output and downgrad<span style="font-size:12px;line-height:102%;font-family:Verdana;">ing</span><span style="font-size:12px;line-height:102%;font-family:Verdana;"> inhibition from S1 to M1.</span>
文摘Background: Work related low back pain has been identified as a one of the most costly disorders among the worldwide working population. This condition was highly prevalent that approximately 85% patients having back pain were brought on by prolonged sitting. With the rapid development of modern technology, sitting has now become the most common posture in today’s work- place. Idea of using motor control learning approach provides the optimal control and coordination of the spine. The McKenzie evaluation was received using repeated movements and sustained positions. Therefore high quality randomized clinical trial was required to compare the effectiveness of these treatments for work related low back pain. Objectives: To compare the effectiveness of motor control exercises and McKenzie exercises in reducing pain and disability in work related low back pain. Method: The study included 40 subjects with work related low back pain due to prolonged sitting. They were randomly allocated into two groups (Group A and Group B). Group A was treated with motor control exercises and group B was treated with McKenzie exercises for 4 weeks. Results: Both the groups have shown statically significant improvement in vas with p < 0.0001 and ODI with p < 0.0001. When the comparison was done after the 4 weeks, the percentage of improvement in group A was much higher than Group B. Conclusion: The study concluded that motor control exercises have shown statically and clinically significant improvement in reducing pain and disability when compared to McKenzie exercises among work related low back pain subjects.
文摘A new control scheme for induction motors is proposed in the present paper, applying the interconnection and damping assignment-passivity based control (IDA-PBC) method. The scheme is based exclusively on passivity based control, without restricting the input frequency as it is done in field oriented control (FOC). A port-controlled Hamiltonian (PCH) model of the induction motor is deduced to make the interconnection and damping of energy explicit on the scheme. The proposed controller is validated under computational simulations and experimental tests using an inverter prototype.
文摘In the context of induction motor control, there are various control strategies used to separately control torque and flux. One common approach is known as Field-Oriented Control (FOC). This technique involves transforming the three-phase currents and voltages into a rotating reference frame, commonly referred to as the “dq” frame. In this frame, the torque/speed and flux components are decoupled, allowing for independent control, by doing so, the motor’s speed can be regulated accurately and maintain a constant flux which is crucial to ensure optimal motor performance and efficiency. The research focused on studying and simulating a field-oriented control system using fuzzy control techniques for an induction motor. The aim was to address the issue of parameter variations, particularly the change in rotor resistance during motor operation, which causes the control system to deviate from the desired direction. This deviation implies to an increase in the magnetic flux value, specifically the flux component on the q-axis. By employing fuzzy logic techniques to regulate flux vector’s components in the dq frame, this problem was successfully resolved, ensuring that the magnetic flux value remains within the nominal limits. To enhance the control system’s performance, response speed, and efficiency of the motor, sliding mode controllers were implemented to regulate the current in the inner loop. The simulation results demonstrated the proficiency of the proposed methodology.
文摘The automation process is a very important pillar for Industry 4.0.One of the first steps is the control of motors to improve production efficiency and generate energy savings.In mass production industries,techniques such as digital signal processing(DSP)systems are implemented to control motors.These systems are efficient but very expensive for certain applications.From this arises the need for a controller capable of handling AC and DC motors that improves efficiency and maintains low energy consumption.This project presents the design of an adaptive control system for brushless AC induction and DC motors,which is functional to any type of plant in the industry.The design was possible by implementing Matlab software and tools such as digital signal processor(DSP)and Simulink.Through an extensive investigation of the state of the art,three models needed to represent the control system have been specified.The first model for the AC motor,the second for the DC motor and the third for the DSP control;this is done in this way so that the probability of failure is lower.Subsequently,these models have been programmed in Simulink,integrating the three main models into one.In this way,the design of a controller for use in AC induction motors,specifically squirrel cage and brushless DC motors,has been achieved.The final model represents a response time of 0.25 seconds,which is optimal for this type of application,where response times of 2e-3 to 3 seconds are expected.
基金supported in part by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China under Grant 21KJA470007。
文摘The complex working conditions and nonlinear characteristics of the motor drive control system of industrial robots make it difficult to detect faults.In this paper,a deep learning-based observer,which combines the convolutional neural network(CNN)and the long short-term memory network(LSTM),is employed to approximate the nonlinear driving control system.CNN layers are introduced to extract dynamic features of the data,whereas LSTM layers perform time-sequential prediction of the target system.In terms of application,normal samples are fed into the observer to build an offline prediction model for the target system.The trained CNN-LSTM-based observer is then deployed along with the target system to estimate the system outputs.Online fault detection can be realized by analyzing the residuals.Finally,an application of the proposed fault detection method to a brushless DC motor drive system is given to verify the effectiveness of the proposed scheme.Simulation results indicate the impressive fault detection capability of the presented method for driving control systems of industrial robots.
文摘Spinal cord injury (SCI) is a major cause of disability. A serious consequence of SCI is the loss or partialloss of motor control. A number of therapies are currently being developed for restoring motor function in SCI patients. However, such approaches generally require intact neural motor systems for driving limb movements. There is evidence that SCI can generate such conditions in the brain,
文摘This article introduces the control principle,technical status and two commonly used motor control schemes of permanent magnet synchronous motors for new energy vehicles.Direct torque control is selected as the research object,and its advantages and disadvantages with vector control are analyzed.A Simulink simulation model was established according to the control principle.
基金The study was funded by the Transport Accident Commission(Victorian Neurotrauma Initiative),and the University of Melbourne
文摘Aim:The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury(SCI)post intensive whole-body training vs.upper body training with brain motor control assessment(BMCA).Methods:Twelve neurologically intact participants and 18 patients with SCI participated in this study as part of a multi-centre randomised controlled trial.All participants received 12 weeks training(three times per week),which comprised trunk,upper and lower limb exercises and locomotor training and functional electrical stimulation-assisted cycling in whole-body training group and an upper body strength and fitness program for upper body training group.Results:Generalised linear model analysis showed significant effect of the main effect of the Task(P<0.001)on the similarity index of voluntary movement patterns but not on the other factors or the interactions between them(P>0.05).Some participants showed significant improvement in muscle strength post 12 weeks training;however,this improvement was not reflected in the pattern of muscle activation which was captured by BMCA.Conclusion:BMCA is a valuable objective assessment tool that could add resolution to the clinical evaluation of patients with SCI post different therapeutic techniques.
文摘The article is designed hardware platform of TMS320F2812 primary control chip based on the motor drive controller outputs and input signal, the use of DSP technology, together with the corresponding peripheral driver circuit, a signal processing circuit and other processing module, the design and realize a piece of printed circuit board to achieve the required functionality. Systems software modules is implement hardware configuration and achieve control strategies in the DSP CCS compiler environment and using C and assembly language. Through CAN controller that comes with the DSP programming, achieved its CAN signal transmission and reception.
文摘DTC (direct torque control) of induction motor drives has many outstanding performance and implementation properties. This paper presents an innovative direct torque controlled load generator based on space vector modulation suitable for the emerging applications such as electrical test benches that require extremely fast large-signal torque and dynamic responses. To realize system performance, two methods based on the classical DTC (with six-sector switch table) and the proposed twelve-sector DTC have been analyzed and used for modelling the dynamometer. The performance of the proposed dynamometer is investigated by simulating different parts of the system and results are presented for several industrial load profiles. Finally, limitations and advantages of each controller are presented and analyzed.
文摘This paper describes the incremental PID control algorithm and the basic principles of motor soft start, and introduced STM32F103RB8 basic performance microcontroller, combined with incremental PID control advantages, and gives MCU in motor soft start process control application. Practice shows that the incremental PID applications, simplifying the control ideas to improve the performance of the current loop control, limiting the starting current, smooth start-up speed, and achieved good results motor start.
基金supported by the Burke Foundation and the National Institutes of Health Common Fund,No.DP2 NS106663(to ERH)the New York State Department of Health Spinal Cord Injury Research Board Postdoctoral Fellowship,No.C32633GG(to YL)。
文摘Therapeutic intervention for spinal cord injury is limited,with many approaches relying on strengthening the remaining substrate and driving recovery through rehabilitative training.As compared with learning novel compensatory strategies,rehabilitation focuses on resto ring movements lost to injury.Whether rehabilitation of previously learned movements after spinal cord injury requires the molecular mechanisms of motor learning,or if it engages previously trained motor circuits without requiring novel learning remains an open question.In this study,mice we re randomly assigned to receive intrape ritoneal injection with the pan-nicotinic,non-competitive antagonist mecamylamine and the nicotinicα7 subunit selective antagonist methyllycaconitine citrate salt or vehicle(normal saline)prior to motor learning assays,then randomly reassigned after motor learning for rehabilitation study post-injury.Ce rvical spinal co rd dorsal column lesion was used as a model of in complete injury.Results of this study showed that nicotinic acetylcholine signaling was required for motor learning of the single pellet-reaching task but it was dispensable for the rehabilitation of the same task after injury.Our findings indicate that critical diffe rences exist between the molecular mechanisms supporting compensatory motor learning strategies and the restoration of behavior lost to spinal cord injury.
文摘The bearingless induction motor, which combines the inductionmotor and magnetic bearing is a strongly coupled complicatednonlinear system; the decoupling control of the electromag- net toqueand readial levitation force is the base of the stable operation ofthe benaringless motor. In this paper, the air-gap motor fluxoriented vector control is proposed to realize the decoupling controlof this nonlinear system even in the transient case based on thelevitation principle. Simulations show the stable suspension and goodperformance of the proposed algorithm.
基金The Project Supported by Doctoral Programme Foundation of Institution of Higher Education
文摘Pump controlled motor electrohydraulic servo systems are much used in circumstances where high power drive is needed. This kind of system has the advantage of energy-saving. But, it also has some defects that have to be improved. Microcomputer control of a pump controlled motor electrohydraulic servo system is studied. A PID controller is first adopted on the closed loop control system, and experimental results are obtained. Then, a model reference adaptive controller is designed and realised on the same system applying a single board microcomputer. Experimental results show that the dynamic properties of the adaptive control system is much better than those of the PID system under different inertia load conditions.