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Abstract Phototheranostics has garnered sustained attention due to its significant potential for revolutionizing conventional cancer treatment strategies. While being one of the most commonly employed strategies for constructing phototheranostic systems by engineering the integration of photosensitizers (PSs) into nanosystems, nano‐PSs face challenges including complexity in the preparation process, low delivery efficiency, and potential toxicity issues. Contrastingly, the burgeoning popularity of small molecule PSs characterized by aggregation‐induced emission (AIE) has become evident in the arena of cancer phototheranostics. This preference is underscored by their well‐defined structures, adjustable photophysical properties, and low toxicity. Therefore, acquiring profound insights into the pioneering strides achievable through a solitary small molecule PS with AIE in tumor phototheranostics is of paramount scientific significance. In this review, we will discuss the recent progress of small molecule PSs with AIE properties in cancer diagnosis and phototherapies with representative examples, guided by the ethos of “Complexity made easy”. We also look forward to the future development direction of AIE small molecules, with a central objective of advancing cancer research through a focal emphasis on simplicity, expeditiousness, and safety.

Industrial mobile robots easily experience actuator loss of some effectiveness and additive bias faults due to the working scenarios, resulting in unexpected performance degradation. This article proposes a novel adaptive fault-tolerant control (FTC) strategy for nonholonomic mobile robot systems subject to simultaneous actuator lock-in-place (LIP) and partial loss-of-effectiveness (LOE) faults. First, a nominal fractional-order sliding mode controller based on the designed exponential super-twisting reaching law is investigated to reduce the reaching phase time and eliminate the chattering. To address the time-varying LIP faults and uncertainties, a novel barrier function (BF)-based gain is explored to assist the super-twisting law. An estimator is designed to estimate the lower bound of the time-varying partial LOE fault coefficients, thus without requiring the boundary information of faults that is commonly requested in traditional FTC schemes. Combined with the nominal controller clubbed with BF and estimator-based LOE fault compensation term, the fault-tolerant controller is finally constructed. The proposed FTC scheme achieves fast convergence and the sliding variables can be confined in a predetermined neighborhood of the sliding manifold under actuator faults. The results show that the proposed controller has superior tracking performance under faulty conditions compared with other state-of-the-art adaptive FTC approaches.

The development of advanced sensing and control technologies provides increased intelligence and autonomy for robots and enhances the robots’ agility, maneuverability, and efficiency, which has attracted growing attention in various industries and domains [...]

Abstract 5-methylcytosine (m5C) modification, which is mainly induced by the RNA methyltransferase NSUN2 (NOP2/Sun domain family, member 2), is an important chemical posttranscriptional modification in mRNA and has been proven to play important roles in the progression of many cancers. However, the functions and underlying molecular mechanisms of NSUN2-mediated m5C in osteosarcoma (OS) remain unclear. In this study, we found NSUN2 was highly expressed in OS tissues and cells. We also discovered that higher expression of NSUN2 predicted poorer prognosis of OS patients. Our study showed that NSUN2 could promote the progression of OS cells. Moreover, we employed RNA sequencing, RNA immunoprecipitation (RIP), and methylated RIP to screen and validate the candidate targets of NSUN2 and identified FABP5 as the target. We observed that NSUN2 stabilized FABP5 mRNA by inducing m5C modification and further promoted fatty acid metabolism in OS cells. Moreover, both knocking down the expression of FABP5 and adding fatty acid oxidation inhibitor could counterbalance the promoting effect of NSUN2 on the progression of OS. Our study confirms that NSUN2 can up-regulate the expression of FABP5 by improving the stability of FABP5 mRNA via m5C, so as to promote fatty acid metabolism in OS cells, and finally plays the role in promoting the progression of OS. Our findings suggest that NSUN2 is a promising prognostic marker for OS patients and may serve as a potential therapeutic target for OS treatment. A schematic illustration was proposed to summarize our findings.

As a fundamental issue in robotics academia and industry, indoor autonomous mobile robots (AMRs) have been extensively studied. For AMRs, it is crucial to obtain information about their working environment and themselves, which can be realized through sensors and the extraction of corresponding information from the measurements of these sensors. The application of sensing technologies can enable mobile robots to perform localization, mapping, target or obstacle recognition, and motion tasks, etc. This paper reviews sensing technologies for autonomous mobile robots in indoor scenes. The benefits and potential problems of using a single sensor in application are analyzed and compared, and the basic principles and popular algorithms used in processing these sensor data are introduced. In addition, some mainstream technologies of multi-sensor fusion are introduced. Finally, this paper discusses the future development trends in the sensing technology for autonomous mobile robots in indoor scenes, as well as the challenges in the practical application environments.

Abstract Background Functional electrospun membranes are promising dressings for promoting wound healing. However, their microstructure and drug loading capacity need further improvements. It is the first time to design a novel mesh-like electrospun fiber loaded with atorvastatin (ATV) and investigated its effects on paracrine secretion by bone marrow-derived mesenchymal stem cells (BMSCs) and wound healing in vivo. Methods We fabricated a mesh-like electrospun membrane using a copper mesh receiver. The physical properties of the membranes were evaluated by SEM, FTIR spectroscopy, tensile strength analysis, and contrast angle test. Drug release was measured by plotting concentration as a function of time. We tested the effects of conditioned media (CM) derived from BMSCs on endothelial cell migration and angiogenesis. We used these BMSCs and performed RT-PCR and ELISA to evaluate the expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) genes and proteins, respectively. The involvement of FAK and AKT mechanotransduction pathways in the regulation of BMSC secretion by material surface topography was also investigated. Furthermore, we established a rat model of wound healing, applied ATV-loaded mesh-like membranes (PCL/MAT) seeded with BMSCs on wounds, and assessed their efficacy for promoting wound healing. Results FTIR spectroscopy revealed successful ATV loading in PCL/MAT. Compared with random electrospun fibers (PCL/R) and mesh-like electrospun fibers without drug load (PCL/M), PCL/MAT induced maximum promotion of human umbilical vein endothelial cell (HUVEC) migration. In the PCL/MAT group, the cell sheet scratches were nearly closed after 24 h. However, the cell sheet scratches remained open in other treatments at the same time point. The PCL/MAT promoted angiogenesis and led to the generation of longer tubes than the other treatments. Finally, the PCL/MAT induced maximum gene expression and protein secretion of VEGF and b-FGF. As for material surface topography effect on BMSCs, FAK and AKT signaling pathways were shown to participate in the modulation of MSC morphology and its paracrine function. In vivo, PCL/MAT seeded with BMSCs significantly accelerated healing and improved neovascularization and collagen reconstruction in the wound area compared to the other treatments. Conclusions The mesh-like topography of fibrous scaffolds combined with ATV release creates a unique microenvironment that promotes paracrine secretion of BMSCs, thereby accelerating wound healing. Hence, drug-loaded mesh-like electrospun membranes may be highly efficacious for wound healing and as artificial skin. It is a promising approach to solve the traumatic skin defect and accelerate recovery, which is essential to developing functional materials for future regenerative medicine.

Abstract Background Dysregulated osteoclast activity due to altered osteoclast differentiation causes multiple bone diseases. Osteoclasts are multinucleated giant cells derived from hematopoietic stem cells and play a major role in bone absorption. However, the mechanisms underlying the tight regulation of osteoclast differentiation in multiple pathophysiological status remain unknown. Results We showed that Bhlhe40 upregulation is tightly associated with osteoclast differentiation and osteoporosis. Functionally, Bhlhe40 promoted osteoclast differentiation in vitro, and Bhlhe40 deficiency led to increased bone mass and decreased osteoclast differentiation in vivo. Moreover, Bhlhe40 deficient mice resisted estrogen deficiency and aging-induced osteoporosis. Mechanism study showed that the increase in bone mass due to Bhlhe40 deficiency was a cell intrinsic defect in osteoclast differentiation in these mice. BHLHE40 upregulated the gene expression of Fos and Nfatc1 by directly binding to their promoter regions. Notably, inhibition of Fos/Nfatc1 abrogated the enhanced osteoclast differentiation induced by BHLHE40 overexpression. Conclusions Our research reveals a novel Bhlhe40/c-Fos/Nfatc1 axis involved in regulating osteoclastogenesis and shows that osteoporosis caused by estrogen deficiency and aging can be rescued by regulating Bhlhe40 in mice. This may help in the development of a new strategy for the treatment of osteoporosis.

Hemorrhage, infection, and frequent replacement of dressings bring great clinical challenges to wound healing. In this work, Flammulina velutipes extract (FV) and hydroxyethyl cellulose (HEC) were chemically cross-linked and freeze-dried to obtain novel HFV cryogels (named HFVn, with n = 10, 40, or 70 corresponding to the weight percentage of the FV content), which were constructed for wound hemostasis and full-thickness skin defect repair. Systematic characterization experiments were performed to assess the morphology, mechanical properties, hydrophilic properties, and degradation rate of the cryogels. The results indicated that HFV70 showed a loose interconnected-porous structure and exhibited the highest porosity (95%) and water uptake ratio (over 2,500%) with a desirable degradation rate and shape memory properties. In vitro cell culture and hemocompatibility experiments indicated that HFV70 showed improved cytocompatibility and hemocompatibility. It can effectively mimic the extracellular matrix microenvironment and support the adhesion and proliferation of L929 cells, and its hemolysis rate in vitro was less than 5%. Moreover, HFV70 effectively induced tube formation in HUVEC cells in vitro. The results of the bacteriostatic annulus confirmed that HFV70 significantly inhibited the growth of Gram-negative E. coli and Gram-positive S. aureus. In addition, HFV70 showed ideal antioxidant properties, with the DPPH scavenging rate in vitro reaching 74.55%. In vivo rat liver hemostasis experiments confirmed that HFV70 showed rapid and effective hemostasis, with effects comparable to those of commercial gelatin sponges. Furthermore, when applied to the repair of full-thickness skin defects in a rat model, HFV70 significantly promoted tissue regeneration. Histological analysis further confirmed the improved pro-angiogenic and anti-inflammatory activity of HFV70 in vivo. Collectively, our results demonstrated the potential of HFV70 in the treatment of full-thickness skin defects and rapid hemostasis.

Abstract Objective The purpose of this study is to explore the effect of miRNA-539 on osteosarcoma (OS) and the underlying mechanism, so as to find a new method for early diagnosis and treatment of osteosarcoma. Method miRNA-539 mimics was transfected into osteosarcoma cells 143b and MG-63 and upregulated the expression of miR-539. QT-PCR was used to detect transfection efficacy. CCK-8 method was used to detect proliferation of 143b and MG-63 osteosarcoma cells and flow cytometry was used to detect the apoptosis of osteosarcoma cells 143b and MG-63. Wound-healing test and Transwell test were used to detect the migration and invasion ability of osteosarcoma cells. TRIAP1 was found to be the potential target gene of miRNA-539 by online bioinformatics software and the expression level of TRIAP1 in osteosarcoma cells overexpressing miRNA-539 was detected by qT-PCR. Western blot was used to detect the level of expression of TRIAP1 and its downstream genes (p53, p21, apaf1 and caspase9) in osteosarcoma cells 143b and MG63 transfected with miR-539 mimics or miR-539 mimics-NC. A model of osteosarcoma subcutaneously transplanted in nude mice was constructed to observe the effect of miRNA-539 on the growth rate of osteosarcoma in vivo. Results After transfection of miRNA-539 mimics in osteosarcoma cells 143b and MG63, the proliferation level, migration ability, and invasion ability of the osteosarcoma cells were significantly lower than that in the control group, and the apoptosis level was significantly higher than that in the control group (P

Abstract Background Myeloma bone disease (MBD) is a severe complication of multiple myeloma (MM) mainly due to an imbalance between enhanced osteoclast activity and reduced osteoblast function. Previous studies have demonstrated that miRNAs play a vital role in the osteogenic differentiation of mesenchymal stromal cells (MSCs) in MM. However, the value of miR‑302b in MBD remains to be further elucidated. The aim of this study is to explore the role of miR‑302b in the regulation of MBD osteogenic differentiation and evaluate the potential of a new therapeutic strategy for the clinical treatment of MBD. Method Our previous research demonstrated that MiR-302b belongs to the miR-302 cluster and is able to inhibit tumor growth and osteolysis in an orthotopic osteosarcoma xenograft tumor mouse model. In this study, we first transfected miR-302b mimics, miR-302b inhibitor, and miR-302b NC into MM1.S and RPMI8226 MM cells to detect the correlation between miR-302b expression in the pathological specimens and the clinicopathological features by qPCR, the target correlation between miR-302b and DKK1 by immunohistochemistry, qPCR and Western blot, and the correlation between miR-302b and the Wnt/β-catenin signaling pathway by Western blot. The effect of miR-302b on osteoblastogenesis was also studied in a subperiosteal tumorigenesis model of NOD/SCID nude mice. Results We found that increased miR-302b suppressed cell proliferation and induced cell apoptosis in RPMI 8226 and MM1.S cells. TargetScan online bioinformatic analysis predicted that miR-302b is able to bind to 3′UTR of DKK1 mRNA. Target binding of miR-302b to DKK1 was demonstrated by dual-luciferase reporter assay, qPCR, Western blot and immunohistochemistry, indicating that miR-302b is able to degrade DKK1 in RPMI 8226 and MM1.S cells. The model of co-culturing MM cells with preosteoblast MC3T3-E1 cells showed that miR-302b inhibits MM-induced suppression of osteoblast differentiation. Western blotting showed that miR-302b promotes the Wnt/β-catenin signaling pathway in MM cells. Micro-CT and immunohistochemistry results showed that miR-302b suppresses myeloma bone destruction in vivo. Conclusion miR-302b is able to target DKK1 and promote the Wnt/β-catenin signaling pathway in MM.

R0 surgical resection is the preferred treatment for bone and soft tissue sarcoma. However, there is still a lack of precise technology that can visualize bone and soft tissue sarcoma during surgery to assist the surgeon in judging the tumor surgical boundary. Fluorescence imaging technology has been used in the diagnosis of cancer. It is a simple and essentially safe technique that takes no additional time during the operation. Intraoperative fluorescence imaging has potential application prospects in assisting the surgeons in judging the tumor boundary and improving the accuracy of surgical resection. This review mainly starts with clinical studies, animal experimentation, and newly designed probes of intraoperative fluorescence imaging of bone and soft tissue sarcoma, to appraise the application prospects of fluorescence imaging technology in bone and soft tissue sarcoma.

Model-based approaches are essential for designing cyber-physical systems, which adopt the formal models to simultaneously form the specifications and enable the verification at an early stage. Aimed to model the complex structure and continuous-discrete hybrid behavior of cyber-physical systems, this paper mathematically defines a dynamic relational system so that the cyber-physical system can be regarded as dynamic relational systems in a hierarchical structure and each dynamical relational system is a triple of dynamic attributes, subsystems, and hybrid relations between attributes and subsystems. Every hybrid relation contains a tuple and a predicate to govern the system behaviors. By utilizing the dynamic relational system, a parametric abstraction is then performed to specify the design requirements and schemes. It can represent the structure and behaviors of multiple cyber-physical system design schemes in an integrated manner. With a mathematical foundation, the constructed relational models are beneficial for structural analysis and behavior verification. An implementation case of a friction-driven plate conveyor is presented to illustrate the design specification with relational models, and the connectivity analysis and behavior verifications are carried out to show the effectiveness and engineering practicability of the achieved models.

Nonholonomic four-wheeled mobile robot (NFMR) is a typical multiple input–multiple output system that formulates its kinematic dynamics concerning position and attitude in a parallel manner. However, due to the lumped disturbances and interconnected states, demand-satisfied performance is difficult to obtain for existing coupled control solutions. To address this problem, a double-loop sliding-mode control (DLSMC) mechanism is proposed for achieving position/attitude cascade regulation. For the outer position tracking loop in the proposed scheme, a sliding mode control method of the bounded time-varying integral nonsingular terminal is designed to guarantee fast tracking in the presence of large initial errors and input saturation. On the other hand, for the inner attitude control loop, a novel adaptive barrier function-based sliding-mode control method is proposed without control gain overestimation. This enables the attitude to follow within a predefined vicinity of the sliding mode surface and holds it subsequently independent of the lumped uncertainties. Theoretical analysis is conducted to demonstrate the asymptotic stability. Comparative experiments implemented on a homemade NFMR show enhanced trajectory tracking performance and system robustness using position/attitude cascade regulation via the proposed DLSMC mechanism.

Chemoresistance remains a huge challenge for the treatment of osteosarcoma (OS). Multiple mechanisms are involved in chemoresistance of cisplatin. In our research, we found that Nrf2/xCT pathway contributes to the occurrence of chemoresistance of cisplatin in OS by enhancing the ability of antioxidative stress. Recently, oxidative stress defense and ferroptosis have attracted wildly attention in overcoming chemoresistance. Different from apoptosis, necroptosis, and autophagy, ferroptosis is a new programmed cell death pathway with the accumulation of reactive oxygen species (ROS). Synergistic treatment of ferroptosis and photothermal therapy (PTT) can perfectly overcome chemoresistance, and immunogenic cell death (ICD) induced by PTT can initiate effective anti-tumor immunity to suppress tumor growth and recurrence. Thus, we designed a cancer cell membrane coated gold nanocages loaded with RSL3 (C-R-AuNC) for the treatment of chemoresistance of OS. RSL3 induces ferroptotic cell death by the inhibition of glutathione peroxidase (GPX4). Gold nanocages coated with the cell membrane, as a nanocarrier, can achieve targeted drug delivery, controlled drug release, PTT, and induced ICD. In our researches, excellent outcomes for the treatment of chemoresistance of OS were achieved by C-R-AuNC, which is believed to serve as a promising strategy for clinic treatment of drug-resistant OS in future.

Profiting from its remarkable maneuverability and efficiency, the four-wheeled autonomous mobile robot (FAMR) is appealing for intelligent manufacturing and automation applications. However, the suppression of unknown disturbances and system uncertainties remains a challenge for formulating a precise trajectory-tracking control scheme. This paper achieves the anti-disturbance direct yaw moment control of a developed FAMR by proposing a robust super-twisting sliding mode controller (RSSMC) to enhance the dynamic tracking and disturbance rejection property simultaneously. One of the major contributions is that the presented RSSMC method is constructed with a novel reaching law to eliminate the matched perturbations and time-varying lumped disturbances. As another distinguishing feature, this method is capable of driving the resultant FAMR trajectory into a bounded switching region and maintaining it therein for subsequent periods in finite time. To guarantee the closed-loop stability and finite-time convergence, new sufficient conditions for specifying the variable gains are determined utilizing Lyapunov functions. Finally, under the direct yaw moment control framework, simulation experiments of a developed FAMR system are offered to verify the practicability of the RSSMC scheme.

Objective This study aims to explore the effect of daidzein, which is a natural isoflavone compound mainly extracted from soybeans, on osteosarcoma and the potential molecular mechanism. Material and Methods 143B and U2OS osteosarcoma cells were treated with gradient concentrations of daidzein, and MTT assay was used to determine the cell proliferation capacity and IC50. Hoechst 33342 staining and Annexin V-FITC/PI detection were used to determine apoptosis. Cell cycle was analyzed by flow cytometry, and migration ability were detected by transwell assays and scratch wound assay. An osteosarcoma xenograft mice model was applied to investigate the effect of daidzein on osteosarcoma in vivo. Systematic pharmacology and molecular modeling analysis were applied to predict the target of daidzein to osteosarcoma, and the target Src was verified by western blotting. We also observed the effect of daidzein on cell proliferation and apoptosis of Src-overexpressing osteosarcoma cells. Results In vitro, daidzein significantly inhibited 143B and U2OS osteosarcoma cell proliferation and migration, and induced cell cycle arrest. In vivo, daidzein exerts antitumor effects in osteosarcoma xenograft mice. After systematic screening and analysis, Src-MAPK signaling pathway was predicted as the highest-ranked pathway. Western blot demonstrated that daidzein inhibited phosphorylation of the Src-ERK pathway in osteosarcoma cells. Also, overexpression of Src could partially reverse the inhibitory effects of daidzein on osteosarcoma cell proliferation. Conclusion Daidzein exerts an antitumor effect on osteosarcoma, and the mechanism may be through the Src-ERK pathway.

Radiation-induced bone injury (RIBI) is one of the complications after radiotherapy for malignant tumors. However, there are no effective measures for the treatment of RIBI in clinical practice, and the mechanism of RIBI is unclear. We use a single high-dose ionizing radiation (6Gy) to analyze the effect of radiotherapy on osteoblast function. Human umbilical cord blood mesenchymal stem cells (hUCB-MSCs) were cocultured with irradiated osteoblasts to examine their therapeutic effects and mechanisms on osteoblast injury. The hUCB-MSC transplantation mouse model is used to confirm the in vivo role of hUCB-MSC treatment in radiation bone injury. Western blot analysis, qRT-PCR, immunohistochemistry, and immunofluorescence staining were used to analyze gene expression and angiogenesis. The apoptosis and migration of osteoblasts were measured by Hoechst staining, scratch test, and transwell. The differentiation of osteoblasts was measured by ALP and Alizarin red staining and transmission electron microscopy. The bone-related parameters of mice were evaluated by micro-CT analysis. We found that radiation can damage the DNA of osteoblasts; induce apoptosis; reduce the differentiation, migration, and adhesion of osteoblasts, leading to lipogenesis of bone marrow mesenchymal stem cells (BMSCs) and reducing the source of osteoblasts; and increase the number of osteoclasts in bone tissue, while MSC treatment prevents these changes. Our results reveal the inhibitory effect of radiation on osteoblast function. hUCB-MSCs can be used as a therapeutic target for the development of new therapeutic strategies for radiotherapy of bone injury diseases.

Industrial robots can be found in many manufacturing applications that suffer from imprecise position control of their own drive systems due to unknown external disturbances and parametric uncertainties. To address this problem, this paper proposes a robust cascade path-tracking control method to achieve better position control performance for a networked industrial robot. In the joint task space, the cascade control framework is formulated for the developed robotic actuation system, which consists of an inner speed loop and an outer position loop. Instead of exploring the conventional model-based approaches, a multiple degree-of-freedom constrained iterative feedback tuning (CIFT) method is presented to regulate the cascade controller by utilizing the monitored process data straightforwardly. With the integration of the normalized input constraints and position tracking error, the proposed CIFT method seeks an optimal solution to track the desired position profiles with satisfactory accuracy and improved robustness. Theoretical analysis is performed to verify the asymptotical convergence of the closed-loop system. Implemented on a real-time networked industrial robot, experimental results demonstrate that the proposed method can enhance the dynamic path tracking and system robustness during various operating situations.

Four-wheel redundantly-actuated mobile robot (FRMR) offers high controllability and maneuverability for automation applications. However, the robot dynamics and actuator failures are normally omitted in existing kinematic control schemes, which may lead to steering vibration and degraded robustness. To deal with these problems, a fault-tolerant dynamic control method is developed for precise trajectory tracking of the FRMR, which utilizes a two-level structure to cover the wheel-ground interactions and possible actuator failures. In the high level, with a novel fractional-order sliding mode control, this method offers an effective way to regulate the steering angle and eliminate the rotation chattering simultaneously. For the redundantly-actuated issue, a robust allocation solution is presented in the lower level to straightly determine optimal driving torques with full considerations of actuator failures and optimization efficiency. The convergence and stability of the achieved FRMR system are guaranteed theoretically. The experimental comparative results verify that higher tracking precision and enhanced robustness can be obtained using our proposed method.

Structural analysis is a method for verifying equation-oriented models in the design of industrial systems. Existing structural analysis methods need flattening of the hierarchical models into an equation system for analysis. However, the large-scale equations in complex models make structural analysis difficult. Aimed to address the issue, this study proposes a hierarchical structural analysis method by exploring the relationship between the singularities of the hierarchical equation-oriented model and its components. This method obtains the singularity of a hierarchical equation-oriented model by analyzing a dummy model constructed with the parts from the decomposing results of its components. Based on this, the structural singularity of a complex model can be obtained by layer-by-layer analysis according to their natural hierarchy. The hierarchical structural analysis method can reduce the equation scale in each analysis and achieve efficient structural analysis of very complex models. This method can be adaptively applied to nonlinear-algebraic and differential-algebraic equation models. The main algorithms, application cases and comparison with the existing methods are present in this paper. The complexity analysis results show the enhanced efficiency of the proposed method in the structural analysis of complex equation-oriented models. Compared with the existing methods, the time complexity of the proposed method is improved significantly.

Due to the praiseworthy maneuverability and actuation flexibility, the in-wheel-motor-driven mobile robots (IWMD-MR) are widely employed in various industrial fields. However, the active estimation and rejection of unknown disturbances/uncertainties remain a tough work for formulating a stable lateral motion controller. To address the challenge, this paper proposes a robust lateral stabilization control (RLSC) scheme for the developed IWMD-MR by designing an active disturbance suppression mechanism. The distinctive features of the proposed RLSC method are threefold: (i) With a fuzzy estimator, a modified super-twisting sliding mode method is designed to eliminate the system perturbations and time-varying lumped disturbances in an active manner; (ii) The resultant system trajectory is forced into a bounded switching region within finite time, which can be maintained therein for subsequent periods; (iii) Employing the Lyapunov function, new adaption rules for multivariable gains are derived to preserve the lateral motion stability and robustness. Finally, under the direct yaw moment control framework, simulation experiments of real-life IWMD-MR are offered to verify the effectiveness of the presented RLSC method.

In real-world robotic navigation, some ambiguous environments contain symmetrical or featureless areas that may cause the perceptual aliasing of external sensors. As a result of that, the uncorrected localization errors will accumulate during the localization process, which imposes difficulties to locate a robot in such a situation. Using the ambiguity grid map (AGM), we address this problem by proposing a novel probabilistic localization method, referred to as AGM-based adaptive Monte Carlo localization. AGM has the capacity of evaluating the environmental ambiguity with average ambiguity error and estimating the possible localization error at a given pose. Benefiting from the constructed AGM, our localization method is derived from an improved Dynamic Bayes network to reason about the robot’s pose as well as the accumulated localization error. Moreover, a portal motion model is presented to achieve more reliable pose prediction without time-consuming implementation, and thus the accumulated localization error can be corrected immediately when the robot moving through an ambiguous area. Simulation and real-world experiments demonstrate that the proposed method improves localization reliability while maintains efficiency in ambiguous environments.