Grinding System Research Articles

DEM investigation of SAG mill with spherical grinding media and non-spherical ore based on polyhedron-sphere contact model

In the ore milling process, the ore particles are usually irregular polyhedrons, and the grinding media are often spherical. The need for accurate simulation of this process calls for a contact algorithm between the polyhedron and sphere, achieving a balance of accuracy, stability, and efficiency. For this purpose, we propose a polyhedron-sphere contact model based on the deepest point method. Experiments and simulation studies by discrete element method (DEM) are conducted to test this model's accuracy in a hexahedral box and a lab-scale horizontal drum with lifters. Then, systematic research is carried out for an industrial semi-automatic grinding (SAG) mill to explore the effect of particle shape. To reveal the advantage over the traditional spherical DEM model, the polyhedron-sphere (PH-SP) grinding system is compared with a pure spherical grinding system. Results are discussed from the motion behavior particles, power consumption, collision energy on ore and liner, and liner wear. The results show that the charging of particles in the PH-SP grinding system is blocked to a certain extent by polyhedral particles, both the power consumption and energy utilization efficiency increase somewhat, the large energy collision between ore and liner has increased significantly. The liner wear of the PH-SP grinding system is more severe than the pure spherical grinding system, which indicates that the new model is necessary for more accurate prediction of the grinding process.

Novel insights into the reoxidation of direct reduced iron (DRI) during ball-mill treatment: A combined experimental and computational study

High quality direct reduced iron (DRI) plays a fundamental role in determining the functional properties of high-quality steel. DRI powder with a metallization ratio of 82.82% was obtained by reduction-grinding separation of low-grade iron ore, and iron resource was recycled (recovery ratio: 87.96%). However, a serious reoxidation phenomenon occurs in the grinding system, which is also a common problem in extraction metallurgy based on this process. Therefore, a combined experimental and computational study was executed to investigate the reoxidation. Phase evolution analysis shows that Fe0 in bulk iron particles mainly shift to Fe2+ during the grinding process, while Fe3+ are the main valence state on the nano-surface, indicating the reoxidation occurs via diffusion from the nano-surface to the interior. The cleavage surfaces (Fe100/110) occurred in grinding process are more easily to form FeO ionic bonds with O2, especially when surface defects appear, as calculated by DFT. Further, the deeper iron atoms are more exposed after the defected iron surfaces combine with O2, greatly increasing contact opportunities of FeO2. Therefore, the reduction time should be appropriately extended to decrease the surface defects of new iron, and other wet ball mills should be selected for the treatment of DRI produced by this process.

Dimensional Analysis and Surface Characterization of Ground Alumina Sintered Guide Pin

Alumina (Al2O3) has been considered as satisfactory material used for ceramic guide pin in mechanical engineering applications owing to its excellent properties particularly high strength, good wear and corrosion resistance and extremely low thermal conductivity. However, there is still a major concern with regard to the manufacturing process of the ceramic guide pin, especially in controlling dimensional consistency after the sintering process, leading to part rejection. In this work, the manufacturing of alumina guide pin using powder processing is presented. The focus of this paper is to evaluate dimensional changes and surface analysis of the ground sintered guide pin using an upgraded grinding system. Alumina ceramic guide pin samples were fabricated by a Cold Isostatic Pressure (CIP) technique with four different range of diameters known as M6, M8, M10 and M12. All samples underwent sintering process at 1600°C, followed by secondary process by a micro-grinder to remove excessive diameter after sintering. Dimensional measurement was taken using a Vernier calliper, before and after the grinding process for evaluation. The surface roughness of the guide pin was then analysed by a surface roughness analyser followed by morphological analysis by scanning electron microscopy (SEM). From the result obtained, it clearly showed that, the proposed method of post-processing using of micro-grinding has worked successfully in reducing numbers of part rejection by the company owing to the inconsistency of dimensional changes after the sintering process. Diameter reduction of about 20 – 50 μm was done for all guide pin models corresponded to the improved surface roughness of Ra, Ry and Rz by 1.3 to 2.0 μm, 8.5 to 11.0 μm and 5.0 to 7.0 μm, respectively. From the SEM analysis, better surface morphology was observed corresponded to surface roughness improvement.

A Survey and Analysis on Electricity Consumption of Raw Material Mill System in China Cement Industry between 2014 and 2019

In the whole process of cement production, the electricity consumption of a raw material mill accounts for about 24% of the total. Based on the statistics of the electricity consumption of the raw material mill system of 1005 production lines in China between 2014 and 2019, it is found that the average electricity consumption of the raw material preparation process of all clinker production lines between 2014 and 2019 was 25.2 kWh/t. The average electricity consumption of different-tonnage production lines varies with time. In comparison with high-tonnage ones, the electricity consumption of low-tonnage production lines has wider distribution. The average electricity consumption of raw material mill dropped from 30.88 kWh/t in 2014 to 16.13 kWh/t in 2019, with a drop of more than half. At present, the raw material preparation process of new drying-process cement production enterprises mainly includes middle unloading drying tube mill raw material preparation system, vertical mill raw material final grinding system, and roller press raw material final grinding system. This paper compares the characteristics of several grinding systems and summarizes their influence on the electricity consumption.

Configuration of product plan based on case reasoning of extenics

Through extenics-based case reasoning, this research puts forward a method to configure the modules of complex machine products. Firstly, the knowledge on the process of product design was represented, and the convergence modes of design plans were analyzed, with the aid of product semantics and the knowledge representation model of the primitives. Next, the semantic correlation function was constructed, and a priority degree evaluation method for product family was created, in order to obtain the optimal configuration plan. In this way, the excellent design genes in product plans with relatively low correlations will be preserved. Finally, the proposed method was verified on the design of computer numerically controlled (CNC) roll grinder. Specifically, the quantitative and qualitative user needs were converted into the design objectives, producing the set of primitives (design objectives). Based on sematic correlations and priority degrees, the product/product family that best match the conceptual product was searched for in the case library, and the optimal configuration plan was prepared, in the light of semantic correlation network and local correlation evaluation. The results show that the local correlations of the bed and workbench module, headstock module, grinding system, measuring system, and support of MK8420 with design objectives were 0.298, 0.450, 0.600, 0.500, and 0.298, respectively, indicating that the configuration plan is in line with user needs and suitable for case-based reasoning. The proposed method has been successfully applied in actual production, laying a good basis for the intelligent design of products.

Machine Learning-Based Wheel Monitoring for Sapphire Wafers

The thinning of sapphire wafers is a key process that affects the quality of optoelectronic devices. In the grinding process for sapphire, a hard and brittle material, the grade and surface conditions (wearing and chip loading) of the grinding wheel are the key to continuous processing and reduction of defects. In industry, a common approach is to assume the possible causes of defects by observing the spindle current during the grinding process and the finished product after processing. Thus far, there has been no effective method to quantify the grade and no real-time monitoring technology for grinding wheels. This research proposes a wheel monitoring system that utilizes acoustic emission (AE) signals and radial/axial vibration signals to extract characteristic parameters via popular machine learning classification algorithms (k-NN, ANN, and SVM) in order to identify the signal and characteristic parameters of the wheel during the grinding process. The experimental results show that the AE signal identification accuracy of the grade is excellent, at 99%. The vibration signal of the wheel surface condition during the grinding process is significant as well, yielding an identification accuracy of 91%. The extracted signal characteristics in this research not only quantify the state of the grinding wheel, but also facilitate a wheel monitoring system based on the identification technology. The proposed method for grinding wheel processing status monitoring can be used to establish an automated intelligent grinding system.

Surface roughness prediction model of GH4169 superalloy abrasive belt grinding based on multilayer perceptron(MLP)

GH4169 nickel-based alloy materials are widely used in the design of aero-engine compressor terminal stators and rotor blades because of their high strength, oxidation resistance and gas corrosion characteristics in high-temperature environments. In addition, the advantages of abrasive belt grinding in the processing of nickel-based alloy blades, such as low temperature and strong vibration absorption, can effectively improve the surface integrity and be popularized and applied by aviation manufacturers. However, due to the random distribution of abrasive grains, grinding heat and machining chatter during the abrasive belt grinding process, there is a coupling and strong nonlinear model relationship between the grinding process parameters and the surface roughness after grinding. At present, the strong nonlinear model relationship of multi-dimensional parameters and their coupling relationship has not been resolved, so it is difficult to achieve accurate prediction of surface roughness.We propose a study on the multi-dimensional parameter model of abrasive belt grinding for the decision-making of the surface integrity characteristics of nickel-based alloy blades. Based on the MLP multi-layer perceptron, a prediction model of abrasive belt grinding surface roughness is proposed. According to the multi-layer perceptron model and the input parameter characteristics of the belt grinding system, the initial connection weight and paranoia, the backward propagation algorithm, and the neural network layer are optimized. Through the above algorithm, a multi-dimensional parameter surface integrity nonlinear model is obtained and combined with boundary conditions to achieve accurate prediction of the surface roughness of nickel-based alloy abrasive belt grinding.

Precision EDM of Micron-Scale Diameter Hole Array Using in-Process Wire Electro-Discharge Grinding High-Aspect-Ratio Microelectrodes

Micro-electrical discharge machining (micro-EDM) is a good candidate for processing micro-hole arrays, which are critical features of micro-electro-mechanical systems (MEMS), diesel injector nozzles, inkjet printheads and turbine blades, etc. In this study, the wire vibration of the wire electro-discharge grinding (WEDG) system has been analyzed theoretically, and, accordingly, an improved WEDG method was developed to fabricate micron-scale diameter and high-aspect-ratio microelectrodes for the in-process micro-EDM of hole array with hole diameter smaller than 20 μm. The improved method has a new feature of a positioning device to address the wire vibration problem, and thus to enhance microelectrodes fabrication precision. Using this method, 14 μm diameter microelectrodes with less than 0.4 μm deviation and an aspect ratio of 142, which is the largest aspect ratio ever reported in the literature, were successfully fabricated. These microelectrodes were then used to in-process micro-EDM of hole array in stainless steel. The effects of applied voltage, current and pulse frequency on hole dimensional accuracy and microelectrode wear were investigated. The optimal processing parameters were selected using response–surface experiments. To improve machining accuracy, an in-process touch-measurement compensation strategy was applied to reduce the cumulative compensation error of the micro-EDM process. Using such a system, micro-hole array (2 × 80) with average entrance diameter 18.91 μm and average exit diameter 17.65 μm were produced in 50 μm thickness stainless steel sheets, and standard deviations of hole entrance and exit sides of 0.44 and 0.38 μm, respectively, were achieved.

The Effect of Grinding Wheel Contact Stiffness on Plunge Grinding Cycle

This paper presents the effect of grinding wheel contact stiffness on the plunge grinding cycle. First, it proposes a novel model of the generalized plunge grinding system. The model is applicable to all plunge grinding operations including cylindrical, centerless, shoe-centerless, internal, and shoe-internal grinding. The analysis of the model explicitly describes transient behaviors during the ramp infeed and the spark-out in the plunge grinding cycle. Clarification is provided regarding the premise that the system stiffness is composed of machine stiffness and wheel contact stiffness, and these stiffnesses significantly affect productivity and grinding accuracy. The elastic deflection of the grinding wheel is accurately measured and formulas for representing the deflection nature under various contact loads are derived. The deflection model allows us to find the non-linear contact stiffness with respect to the normal load. The contact stiffnesses of four kinds of grinding wheels with different grades and bond materials are presented. Both cylindrical grinding and centerless grinding tests are carried out, and it is experimentally revealed that the time constant at ramp infeed and spark-out is significantly prolonged by reducing the grinding force. It is verified that a simulation of the grinding tests using the proposed model can accurately predict critical parameters like forces and machine deflection during plunge grinding operations. Finally, this paper provides a guideline for grinding cycle design in order to achieve the required productivity and grinding accuracy.

An adaptive parameters adjustment and planning method for robotic belt grinding using modified quality model

As a kind of flexible manufacturing system, the machining quality of a robotic belt grinding system is related to a variety of factors with strong time variation, which easily leads to process fluctuations and affects the final quality. Therefore, it is a great challenge to control the quality precisely during the whole grinding procedure. Focusing on this problem, an adaptive parameters adjustment and planning method for robotic belt grinding using the modified quality model is proposed in this paper. Firstly, the correlation analysis method of grinding parameters in time domain is presented based on an improved-Mahalanobis distance. The response surface methodology (RSM) is utilized to construct the quality prediction model, and furtherly the parameter sensitivity function, which can characterize the influence degree of different parameters on the grinding quality, is introduced to calculate the Mahalanobis distance for improving the accuracy of the correlation analysis method. Secondly, based on the correlation analysis, a conversion method from the old samples into the new samples space is presented using vector field smoothing algorithm (VFS), then the modified grinding quality model can be re-established adopting the new samples. Furtherly, taking the problem of poor robotic response rate into consideration, a multi-parameters collaborative planning method under the smoothness constraint is developed using particle swarm optimization (PSO) algorithm, which can avoid the parameter mutation and improve the process stability. Finally, belt grinding experiments on a curved surface were carried out based on the robotic grinding platform. The results show that the approach can improve the grinding shape accuracy, which verify the effectiveness of the proposed methods.

Effect of vacuum grinding and storage under oxygen free condition on antioxidant activity and bacterial communities of strawberry puree

The purpose of this study is to investigate the effects of vacuum processing on antioxidant activity and microbial growth of strawberry puree over day 10 after storage at 5, 25, and 35 °C. The strawberry puree was prepared under vacuum (7.2 Pa) using a specially designed grinding and packaging system. Grinding under vacuum resulted in significantly greater antioxidant activity retention (78.6–92.1%) as compared to grinding in atmospheric conditions (48.4–68.2%) during storage at all temperatures. Samples ground under vacuum showed delayed or no growth of total aerobic counts, anaerobic bacteria, and mould and yeast, while control groups showed significant microbial growth. Taxonomic composition analysis of samples at day 7 and 25 °C, showed the most abundant bacteria of the control group were from the genus Rahnella belonging to the phylum Proteobacteria, while those of the vacuum-processed groups were from the genus Lactobacillus belonging to the phylum Firmicutes. Consequently, vacuum grinding and packaging can be used in developing technology for preservation of nutritional quality and microbial safety of strawberry puree.

PERHITUNGAN SISTEM HIDROLIK UNTUK PENGGERAK PISAU PADA MESIN PENGHAPUS MARKA JALAN

<p>One of very important and vital tool in road marking is road mark erasing machines. In general, the machine used to repair road markings is a road marking erasing machine that is pushed manually. However, this machine has a disadvantage that requires a long time in the process of erasing the road marking, so making it less efficient. Therefore, the truck road mark erasing machine is one of the options to replace the erasing machine that is pushed manually. The machine uses a grinding system with a vertical blade eraser position and hydraulic power to drive the blades as it is able to withstand shock loads and thrust upwards due to the removal process, having overload protection, and the size of components are not large. The study started with doing observation to the existing manual erasing machine, then determining the required blades and calculating as well as selecting the required components of the hydraulic system. Based on the calculation, the blade specification was obtained and selected, i.e <em>surface milling cutter</em> of type WFX12200R from Sumitomo Electric Hardmetal Corporation having rotation speed 750 rpm, hydraulic motor from Danfoss of type OMR-80 having torque 136 Nm dan displacement 80.3 cc/rev., and using hydraulic pump from Parker of type 0210 having displacement 21 cc/rev. From the test result in the field, this machine is three times faster than the manually pushed machine, less number of the blade used, and the engine as a resource on the machine is more durable. <strong></strong></p>

Thermal processing under oxygen–free condition of blueberry puree: Effect on anthocyanin, ascorbic acid, antioxidant activity, and enzyme activities

The effect of thermal treatment of blueberry was investigated using a designed grinding and continuous packaging system under oxygen–free conditions. The grinding, packaging, and heating at 90 °C for 30 min under anaerobic condition were compared to heating under aerobic conditions, showing complete inactivation of oxidative enzymes. Heating without oxygen retained anthocyanins and ascorbic acid whereas heating in atmospheric air does not. Delphinidin glycoside was mostly influenced by oxygen deficiency during heating, followed by petunidin and malvidin glycosides. The differences in oxygen sensitivity may be closely associated with the number of hydroxylation in the B ring. The result of anthocyanin led to higher antioxidant activity and redness values of purees heated without oxygen than purees heated with oxygen. Consequently, thermal processing under oxygen–free condition can prevent oxidation of anthocyanin, resulting in higher retention of color and nutritional values of blueberry products.

Development of an intelligent grinding system for fabricating aspheric glass lenses

Precision optical systems, such as lithographic projection lens or cameras for satellites, typically composed of glass or ceramics optical components. In the manufacturing processes of glass and ceramics components, grinding is a key technique for curvature generation (CG) of optical surface. However, dimension errors and sub-surface damage (SSD) of components occur during the CG process. High material removal rates during the CG leads to deeper SSD on optical surface. The SSD must be removed by subsequent lapping and polishing processes to ensure high optical surface quality. However, these processes are complex, and a precise process to remove SSD from the aspheric surfaces with tens or hundreds of microns of departure from best fit sphere (BFS) is required. Thus, an efficient precision lens fabrication method can reduce the depth of SSD and help to control the dimension error during the CG process. We developed a five-axis grinding system with intelligent machining techniques to improve the quality of CG process. The intelligent grinding system based on the Tongtai five-axis machine (GT-630) was combined with two measurement modules of the Renishaw measurement probe. A customized computer-aided manufacturing software was developed and applied to this grinding system. Spherical and aspherical components with a maximum diameter of 600 mm can be fabricated using the grinding system. To improve the grinding efficiency, an ultrasonic-assisted module was combined with the BBT 40 tool arbor. The frequency range, amplitude, and power of the ultrasonic device were 15–40 kHz, 0.2–2 μm, and 1000 W, respectively. The intelligent grinding system included several vibration, temperature, and acoustic emission sensors and a microphone to monitor the dynamic status of machine during the grinding process and help to quality control. The wear of the diamond grinding wheel could be predicted immediately by analyzing the collected data in this system. A five-axis machine was applied to an intelligent grinding system for large glass lenses. The fabrication time of 200 mm diameter aspheric lenses reduced about 3 weeks by using this intelligent grinding system to integrate aspherization processes into curvature generation to become an aspheric curvature generation step.

Multi-information fusion-based belt condition monitoring in grinding process using the improved-Mahalanobis distance and convolutional neural networks

Due to the advantages of flexibility, high efficiency, and low processing heat, belt grinding has been widely applied in manufacturing industries. As belt wear will cause deterioration of the removal capacity, increasing the surface irregularity and adversely affecting the grinding quality, interests in belt condition monitoring have signficantly augmented in recent years, which not only secures the surface quality, but also helps to optimize the utilization of the belt’s life cycle. A multi-information fusion-based belt condition monitoring method in grinding process using the improved-Mahalanobis distance and Convolutional Neural Networks (CNN) is proposed in this paper. Firstly, a time-domain mapping relationship between belt wear and material removal rate is put forward and a factor k t is derived to characterize the wear status. Furtherly, the evolution of abrasive grains degradation as well as the wear effect on grinding quality is analyzed. Secondly, a parallel multi-sensor integration grinding system including force, vibration, sound and acoustic emission sensors is established, based on which the single-factor and multi-factor sensitivity experiments are conducted to determine the optimal combination of characteristic signals. Finally, a multi-layer model including the grinding conditions classification and belt stages identification is established adopting the methods of improved-Mahalanobis distance and CNN. On one hand the model is not limited to a fixed condition and has a wider application scope, on the other hand avoids the impact of human experience on the features extraction and improves the model accuracy from the theoretical perspective. The experimental results show that the identification accuracy of the belt wear stage adopting the method in this paper is no less than 94 % for the 16 sampling conditions and more than 86 % for other grinding conditions. Furtherly, the contrast experiments indicate that the method in this paper is of a higher accuracy than the single-layer CNN model, which proves the effectiveness of the proposed method.

Prototipo de Producción de Composta Sustentable y Amigable con el Medio Ambiente

En la Unidad Profesional Adolfo López Mateos – IPN se cuenta con una planta productora de composta desde 1999 la cual genera 2250 toneladas de composta al año, pero no tiene la capacidad para procesar todos los residuos orgánicos de cada Unidad Académica. Tomando en cuenta todos los residuos generados en UPIBI-IPN, se diseñó un prototipo de producción de composta (Lombricomposta), cuyo objetivo fue disminuir la huella ecológica, generada por la institución, siendo un indicador ambiental, proporcionando datos relevantes para el diseño del prototipo. “La huella ecológica mide la superficie necesaria para producir los recursos consumidos por un ciudadano medio de una determinada comunidad, así como la necesaria para absorber los residuos que genera, independientemente de donde estén localizadas estas áreas” (p12). llevadas a cabo en el periodo enero 2018 – diciembre 2019, e incluyo una estructura integrada por cuatro cajas de acrílico, sistema de triturado; accionada por una bicicleta fija. El compostaje ha ganado popularidad en los años recientes, lo cual logró evolucionar los sistemas convencionales de producción de composta, haciéndolos interactivos, motivadores e integradores, no requiere de energía, es sustentable y además promovió la actividad física en la institución.

Human-machine-environment information fusion and control compensation strategy for large optical mirror processing system

Large optical mirrors require an ultra-precise machining equipment, and a high level of surface-forming precision must be achieved. However, optical mirror processing systems (OMPSs) are susceptible to human behaviors, mechanical structural errors, and processing environments. The factors that affect quality include artificially formulated processes, slurry choice, joint friction, force-induced deformation, ambient temperature, and vibration interference. These factors can lead to a decrease in the accuracy of an OMPS. To study the influence of disturbances in the human-machine-environment (HME) on the OMPS, it is necessary to conduct a fusion analysis of the related factors. A parameter analysis is first conducted on the HME factors that influence the accuracy of OMPS. Then, the factors that influence the accuracy most significantly are determined. Subsequently, with the influencing factors as input parameters, and the output forces of the computer-controlled optical surface (CCOS) grinding system as the output parameters, the HME influencing factors are fused through a BP neural network optimized using a genetic algorithm, and the result is compared with that resulting from the original BP neural network fusion. Finally, according to the results of the fusion, environmental control of the processing system is performed, and the feedforward PD control compensation measures are established for the joint friction. An experimental analysis is also conducted to verify the effect of the information fusion and error compensation on the accuracy of the OMPS.

The Design of an Infeed Cylindrical Grinding Cycle

This paper synthesizes the design of an infeed cylindrical grinding system into a total system composed of the grinding mechanism and the grinding machine characteristics. The causalities between the grinding parameters and the machine structures are discussed, and the infeed grinding processes are analyzed as outputs that represent responses to the inputs. These relationships are integrated into a block diagram with closed-loop feedback. A novel model exhibiting practical parameters such as grinding speed, infeed rate and MRR (Material Removal Rate) is proposed. The analysis of the grinding system derived a critical factor, the “grinding time contact,” which governs the transient behaviors of process parameters such as forces and machine deflection. The process parameters during the infeed cycle including spark-out grinding were investigated, and the formulas required for the cycle design are presented. Furthermore, to improve accuracy and productivity, the features of the cycle design are described and procedures for controlling size error and roundness are discussed. Finally, the model was verified with infeed grinding tests applied to both the chuck-type cylindrical and centerless grinding methods.

Impact of the Drying Temperature and Grinding Technique on Biomass Grindability

The process of biomass compaction depends on many factors, related to material and process. One of the most important is the proper fragmentation of the raw material. In most cases, more fragmented raw material makes it easier to achieve the desired quality parameters of pellets or briquettes. While the chipping of biomass prefers moist materials, for grinding, the material needs to be dried. As drying temperature changes the properties of the material, these may affect the grinding process. The aim of this work was to determine the influence of the drying temperature of biomass raw material in the range of 60–140 °C on the biomass grindability. To only determine this effect, without the influence of moisture, grinding was carried out on the material in a dry state. The research was carried out on a mill with a knife and hammer grinding system, which is the most popular in the fragmentation of biomass. The analysis of particle size distribution and bulk density of the obtained material was carried out. The energy demand for the grinding process was determined and it was shown that drying temperature, grinding system, and mainly type of biomass affects the grindability.

Robot Grinding System Trajectory Compensation Based on Co-Kriging Method and Constant-Force Control Based on Adaptive Iterative Algorithm

To reduce the grinding trajectory deviation caused by the absolute positioning accuracy of robot, a trajectory compensation method based on Co-Kriging space interpolation method is proposed. Meanwhile, an adaptive iterative constant force control method based on one-dimensional force sensor is proposed to improve the processing quality and efficiency of robot belt grinding. Firstly, an error model based on 6 DOF robot is constructed. Then, considering the workspace of robot belt grinding and the similarity of robot position error, the Co-Kriging compensation algorithm is used to compensate the grinding trajectory, which makes the compensation process convenient and accurate. Then, a grinding dynamics model based on deformation is established, and an adaptive iterative constant force control is proposed for complex robot belt grinding process, which overcomes the instability of grinding force and shortens its convergence time. Finally, the grinding trajectory compensation experiment and the force control experiment of spherical workpiece are carried out. The results show that the space interpolation compensation algorithm based on Co-Kriging method can significantly improve both the space position error of grinding trajectory and the actual error of workpiece, which proves the feasibility of compensation algorithm. Through force control algorithm, the grinding force fluctuation is maintained within 2 N, the mean value, standard deviation and variance of absolute value of force error are significantly reduced, the convergence rate of grinding force and the roughness of workpiece are much better than before, which shows the effectiveness of the proposed force control algorithm.