A Distributed Permanent Magnet Eight-Drive Electric Monorail Crane Travel Control Method

Abstract

This invention provides a distributed permanent magnet eight-drive electric monorail crane driving control method, solving the problem that existing monorail cranes cannot achieve precise control of each drive unit through manual operation. The device first uses onboard sensors and vehicle parameters from a detection unit to determine the vehicle's motor speed, maximum required power, and required torque. The detection unit connects to a control processing unit via a CAN bus. Based on the collected sensing data, the control processing unit establishes a torque distribution model, determines the torque distribution coefficients of each drive unit motor, and calculates the maximum operating efficiency of the drive and braking systems. The vehicle controller in the control processing unit judges the signals from the control unit, and the central processor, based on the torque distribution model, formulates a vehicle control strategy with the maximum operating efficiency of the drive and braking systems and energy saving as control objectives. This strategy dynamically and precisely distributes the torque of each drive unit according to different operating conditions. This invention accurately distributes the torque of each drive unit under all operating conditions, ensuring the safe operation of the monorail crane and reducing energy loss.

Description

Technical Field

[0001] This invention relates to the field of underground auxiliary transport monorail locomotives, specifically a distributed permanent magnet eight-drive electric monorail locomotive travel control method. Background Technology

[0002] As a crucial auxiliary transportation system in the mining industry, the monorail system has faced increasingly higher demands. Within this system, the monorail always runs on I-beam rails on the tunnel roof, effectively overcoming the harsh environment at the tunnel floor. Therefore, its superior transportation performance makes it irreplaceable in auxiliary transportation systems. However, with the widespread use of monorails, some drawbacks have emerged. Ensuring vehicle safety and reducing energy consumption on complex sections with continuous curves has become a pressing problem. Existing control methods all require precise driving parameters for vehicle control. Currently, monorail locomotives rely on sensor data and operator assessment of road conditions to ensure safe operation.

[0003] However, with the existing solution, manual operation on uphill, curves and downhill sections can lead to uneven distribution of drive torque in the drive system, making it impossible to achieve precise control of each drive system. During vehicle operation, this can easily cause significant vehicle body swaying and energy loss, which greatly affects the safe operation of existing mine monorail cranes and leads to unnecessary energy waste. Summary of the Invention

[0004] To overcome the problem in the prior art that monorail gantry cranes cannot efficiently and accurately coordinate the distributed drive system based on the driving state, this invention provides a distributed permanent magnet eight-drive electric monorail crane driving control method. The advantage of this method is that it formulates a vehicle control method based on the torque required by the current driving road conditions and takes the overall efficiency and energy saving of the vehicle drive system as the control objectives. Different vehicle drive modes are activated for different operating conditions to generate the drive and braking torque required by each drive system, thereby realizing the rational distribution of torque of each drive permanent magnet motor and improving the stability of vehicle driving and energy utilization efficiency.

[0005] The present invention achieves its objective by employing the following technical solution: a distributed permanent magnet eight-drive electric monorail crane travel control method, characterized by comprising the following steps:

[0006] Step 1: Based on the structural parameters of the eight-drive electric monorail crane and the data sensed by the speed sensor, such as the reduction ratio, drive wheel radius, and speed, the maximum and rated speed of the permanent magnet motor are calculated. Then, the vehicle controller transmits the collected personnel operation information, speed, and acceleration information to the central processor of the control processing unit via the vehicle CAN bus. After processing, the total power demand, total torque demand, and torque required by the permanent magnet motors of each drive system of the vehicle can be accurately calculated.

[0007] Step 2: The eight-drive electric monorail crane mainly operates under three conditions: light load on a small slope, heavy load on a small slope, and light load on a large slope. Based on the perceived vehicle speed and battery SOC, combined with the output torque collected by the motor torque sensor, a torque optimization distribution mathematical model is established in the control processing unit with the maximum total efficiency of the drive system as the objective function and the torque distribution coefficient of each axle as the variable. This determines the distribution coefficient of each drive unit and ensures the rationality of the torque distribution of each drive unit.

[0008] Step 3: Based on the current speed, output torque, and battery SOC information, the monorail uses the established torque distribution mathematical model to formulate a multi-condition control method with the overall efficiency and energy saving of the vehicle drive system as the control objective. This control method formulates the optimal drive mode for different driving conditions of the monorail, coordinates and controls the dynamic distribution and reasonable braking of the vehicle motor torque, and ensures the accuracy of the control of each drive system.

[0009] Furthermore, in step 1, the calculated maximum speed and rated speed of the motor are:

[0010] The maximum speed of the permanent magnet synchronous motor is:

[0011]

[0012] Where: n max The maximum speed of the motor is r / min; v max i is the maximum speed of the vehicle, in km / h; i0 is the speed ratio of the reducer; r is the radius of the drive wheel, in m.

[0013] The rated speed of the motor is:

[0014]

[0015] In the formula: n0 is the rated speed of the motor, r / min; β is the constant power amplification factor.

[0016] Furthermore, in step 1, the power source for the eight-drive electric monorail crane consists of eight permanent magnet motors on the front, middle 1, middle 2, and rear axles. The sum of the power of these drive motors should meet the power requirements of the entire vehicle under different operating conditions. Generally, the rated power P of the motors is determined by the maximum vehicle speed over 15 minutes. h1The maximum power Pmax of the motor should simultaneously meet the power requirements of the vehicle's maximum speed, maximum gradeability, and 0-7.2 km / h acceleration time. The total power requirement of the monorail gantry's drive motor is:

[0017]

[0018] In the formula: P h1 P h2 P h3 These are the motor power (kW) required for the vehicle's top speed, maximum climbing distance, and acceleration time to 7.2 km / h, respectively. max The maximum power of the motor is kW; η t is the motor efficiency; m is the vehicle mass (kg); f is the rolling resistance coefficient; i max Maximum gradeability, %; v p V is the climbing speed, km / h; δ is the rotational mass conversion factor; t is the acceleration time from 0 to 7.2 km / h, s; v a To accelerate to the final speed, km / h.

[0019] The maximum total torque required by the motor is determined based on the vehicle's fully loaded hill-climbing condition:

[0020]

[0021] In the formula: θ is the track incline angle of the monorail, °; T max The total required torque for the motor is expressed in Nm. Let γ be the longitudinal acceleration of the monorail crane, and γ be the coefficient of inertia (N·s). 2 ) / (m·kg); r is the radius of the drive wheel, m; R is the radius of the load-bearing wheel, m; i0 is the current grade gradient, %. From the above calculations, the maximum power and maximum torque required by the drive motor are 128.32kw and 13600Nm, respectively.

[0022] The rated torque of the motor is:

[0023]

[0024] In the formula P h1 The rated power of the motor is expressed in kW.

[0025] After calculating the total required power and torque of the power source using the above formulas, since the monorail is a distributed drive system, it is necessary to determine the specific parameters of each independent permanent magnet motor. Based on the principle of excellent stability, the parameters of each individual motor on each drive shaft during the monorail's forward movement are as follows: the rated speed of the permanent magnet motors on the front, middle, and rear shafts is 2600 r / min. -1The maximum torque of the front axle motor is 1170 Nm, the maximum torque of the middle axle 1 and middle axle 2 is 1600 Nm, and the maximum torque of the rear axle is 2,430 Nm; the maximum power of a single unit is 16.04 kW.

[0026] Preferably, in step 2, a mathematical model for torque optimization allocation is established using the maximum overall efficiency of the drive system as the objective function and the torque distribution coefficients of each shaft as variables to determine the distribution coefficients of each drive component. The motor torque distribution coefficients for the front axle, center shaft 1, center shaft 2, and rear axle are defined as k. f k m1 k m2 and k r The calculation formula is:

[0027]

[0028] In the formula: T f The torque of the front axle motor is Nm; T m1 The torque of the central shaft 1 motor is Nm; T m2 Let Δt be the torque of the motor on the central shaft 2, Nm; Tr be the torque of the motor on the rear shaft, Nm. Since motor efficiency is related to both speed and efficiency, the motor efficiency function η for speed n and torque T is obtained. f (n, T) f Similarly, the efficiency functions of the motors for the central shaft 1, central shaft 2, and rear axle are η, respectively. m1 (n,T m1 ), η m2 (n,T m2 ) and η r (n,T r The overall efficiency of the vehicle's drive system in drive mode is:

[0029]

[0030] In the formula: T req The required torque for the entire vehicle is Nm; n is the motor speed, r / min; η d The overall efficiency function of the permanent magnet motor drive system. The overall efficiency of the vehicle drive system in braking mode is:

[0031]

[0032] The constraints for the above objective function are:

[0033]

[0034] In the formula: T fmax T m1max T m2max T rmaxThese are the external characteristic torques (Nm) of the front axle, middle axle 1, middle axle 2, and rear axle motors at the current speed.

[0035] Preferably, in step 3, a torque distribution control method is formulated based on the characteristics of the drive system and braking system obtained above. First, it is determined whether the operating handle is a start signal. When a start signal is detected, the vehicle enters drive mode and distributes torque according to the driving demand. If the master controller is activated by the handle, mechanical braking is used to a limited extent to ensure timely braking when the emergency braking limit is exceeded. In addition, mechanical braking is also used when the vehicle battery is low or the vehicle speed is very low. When the vehicle speed exceeds the minimum limit but the battery SOC does not exceed the upper limit, only electric braking is used to improve the energy recovery rate. If the electric braking torque is insufficient, mechanical braking control is then implemented for combined braking.

[0036] Compared with existing technologies, the advantages of this invention are as follows: This invention provides a distributed permanent magnet eight-drive electric monorail gantry crane driving control method. It collects driving information through onboard sensors and calculates the current vehicle control parameters. Combined with driving information obtained through the vehicle controller, it calculates the driving torque required for the current vehicle movement and establishes a torque distribution model. Through a control method aimed at safety and energy saving, it generates the required torque for each drive unit. This control method is more precise and efficient, improving the safety of the monorail gantry crane and reducing energy loss. Attached Figure Description

[0037] Figure 1 This is a structural schematic diagram of a distributed eight-drive permanent magnet electric monorail crane;

[0038] Figure 2 This is a structural block diagram of a distributed eight-drive permanent magnet electric monorail control method;

[0039] Figure 3 This is a block diagram of the detection unit structure for a distributed eight-drive permanent magnet electric monorail crane;

[0040] Figure 4 This is a block diagram of the control unit structure for a distributed eight-drive permanent magnet electric monorail crane;

[0041] Figure 5 This is a block diagram of the control and processing unit structure of a distributed eight-drive permanent magnet electric monorail crane;

[0042] Figure 6 This is a block diagram of the execution unit structure of a distributed eight-drive permanent magnet electric monorail crane;

[0043] Figure 7 This is a flowchart of a control method for a distributed eight-drive permanent magnet electric monorail crane.

[0044] In the diagram: 1. Driver's cab; 2. Battery trolley; 3. Traveling wheels; 4. Drive wheels; 5. Brake shoes; 6. Control processing box; 7. Anti-sway chain; 8. Tunnel roof; 9. Permanent magnet motor controller; 10. Control panel; 11. I-beam rail; 12. Lifting device; 13. Detection unit; 1301. Speed ​​sensor; 1302. Acceleration sensor; 1303. Motor torque sensor; 1304. Tilt sensor; 14. Control unit; 1401. Master control handle; 1402. Operating handle; 15. Control processing unit; 1501. Controller; 1502. Central processor; 1503. Torque distribution model; 16. Execution unit; 1601. Clamping force device; 1602. Braking device; 1603. Drive device. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0046] This embodiment provides a distributed permanent magnet eight-drive electric monorail travel control method, which specifically includes the following steps.

[0047] Step 1: As Figures 1-5 As shown, the present invention provides a technical solution including a cab 1, a battery trolley 2, a drive unit 4, a braking device 5, an anti-sway chain 7, a tunnel roof 8, a control panel 10, an I-beam rail 11, a detection unit 13, a control unit 14, and a control processing unit 15. In the cab 1, the operator controls the drive unit 4 and the braking device through the control panel 10 to ensure the monorail travels safely on the I-beam rail 11. The battery trolley 2 provides kinetic energy for the vehicle's movement. The I-beam rail 11 is connected to the tunnel roof 8 through the anti-sway chain 7.

[0048] The detection unit 13 includes a speed sensor 1301, an acceleration sensor 1302, a motor torque sensor 1303, and a tilt sensor 1304. The tilt sensor 1304 is located above the front of the cab 1 and is used to detect the slope of the monorail travel section in real time. The motor torque sensor 1303 is located below the drive motor and is used to detect the output torque in real time. The speed sensor 1301 is located on both sides of the drive device 2 and is used to detect the real-time speed. The acceleration sensor 1302 is located on the upper part of the control processing box 6.

[0049] The control processing unit 15 includes a vehicle controller 1501, a central processor 1502, and a torque distribution model 1503. The information collected by the speed sensor 1301 in the detection unit 13 is used to calculate the maximum speed and rated speed of the permanent magnet synchronous motor by the central processor 1502 of the control processing unit 15, as follows.

[0050] The maximum speed of a permanent magnet motor is:

[0051]

[0052] Where: n max The maximum speed of the motor is r / min; v max i is the maximum speed of the vehicle, in km / h; i0 is the speed ratio of the reducer; r is the radius of the drive wheel, in m.

[0053] The rated speed of the permanent magnet motor is:

[0054]

[0055] In the formula: n0 is the rated speed of the motor, r / min; β is the constant power amplification factor.

[0056] The control unit 14 includes a master control handle 1401 and an operating handle 1402. The vehicle controller 1501 in the control unit 15 obtains the total power requirement of the monorail drive motor by collecting the opening information of the master control handle 1401 and the operating handle 1402, as well as the sensing information from the aforementioned detection unit 13.

[0057]

[0058] In the formula: P h1 P h2 P h3 These are the motor power (kW) required for the vehicle's top speed, maximum climbing distance, and acceleration time to 7.2 km / h, respectively. max The maximum power of the motor is kW; η t is the motor efficiency; m is the vehicle mass (kg); f is the rolling resistance coefficient; i max Maximum gradeability, %; v p V is the climbing speed, km / h; δ is the rotational mass conversion factor; t is the acceleration time from 0 to 7.2 km / h, s; v a To accelerate to the final speed, km / h.

[0059] The maximum total torque required by the motor is determined based on the vehicle's fully loaded hill-climbing condition:

[0060]

[0061] In the formula: θ is the track incline angle of the monorail, °; Tmax The total required torque for the motor is expressed in Nm. Let γ be the longitudinal acceleration of the monorail crane, and γ be the coefficient of inertia (N·s). 2 ) / (m·kg); r is the radius of the driving wheel, m; R is the radius of the load-bearing wheel, m; J is the moment of inertia of each load-bearing wheel about its axis.

[0062] The rated torque of the motor is:

[0063]

[0064] In the formula P N Let be the rated power of the motor, in kW. From the above calculations, the maximum power and maximum torque required by the drive motor are 128.32 kW and 13600 Nm, respectively.

[0065] After calculating the total required power and torque of the power source using the above formulas, since the monorail is a distributed drive system, it is necessary to determine the specific parameters of each independent permanent magnet motor. Based on the principle of excellent stability, the parameters of each individual motor on each drive shaft during the monorail's forward movement are as follows: the rated speed of the permanent magnet motors on the front, middle, and rear shafts is 2600 r / min. -1 The maximum torque of the front axle motor is 1170 Nm, the maximum torque of the middle axle 1 and middle axle 2 is 1600 Nm, and the maximum torque of the rear axle is 2,430 Nm; the maximum power of a single unit is 16.04 kW.

[0066] Step 2: Using the maximum overall efficiency of the drive system as the objective function and the torque distribution coefficient of each shaft as the variable, a torque optimization distribution model 1503 was established in the control processing unit 15 to determine the distribution coefficients of each drive unit. The motor torque distribution coefficients for the front axle, intermediate shaft 1, intermediate shaft 2, and rear axle are defined as k. f k m1 k m2 and k r The calculation formula is:

[0067]

[0068] In the formula: T f The torque of the front axle motor is Nm; T m Let denoted as the torque of the center axle motor (Nm); Tr be the torque of the rear axle motor (Nm). Since motor efficiency is related to both speed and efficiency, the motor efficiency function η for speed n and torque T is obtained. f (n, T) f Similarly, the efficiency functions of the motors for the central shaft 1, central shaft 2, and rear axle are η, respectively. m1 (n,T m1 ), η m2 (n,T m2 ) and ηr (n,T r The overall efficiency of the vehicle's drive system in drive mode is:

[0069]

[0070] In the formula: T req The required torque for the entire vehicle is Nm; n is the motor speed, r / min; η d The overall efficiency function of the permanent magnet motor drive system. The overall efficiency of the vehicle drive system in braking mode is:

[0071]

[0072] The constraints for the above objective function are:

[0073]

[0074] In the formula: T fmax T m1max T m2max T rmax These are the external characteristic torques (Nm) of the front axle, middle axle 1, middle axle 2, and rear axle motors at the current speed.

[0075] Step 3: The central processor 1502 of the control processing unit 15 formulates the torque distribution strategy of the permanent magnet motor. The central processor 1502 will enable the monorail to enter different drive modes based on the battery SOC information of the battery trolley 2 collected by the vehicle controller 1501, the opening information of the master controller handle 2, the opening information of the operating handle 12, and the sensing information of the detection unit 13.

[0076] like Figure 6 As shown, Driving_S represents the handle opening information; Brake_S represents the master controller handle opening information. min Threshold information for the handle opening of the master controller; T B_req Vehicle braking torque requirements; U min and Z max These are the vehicle speed threshold and braking intensity threshold for determining regenerative braking, respectively; SOC min and SOC max These are the SOC thresholds that allow the vehicle to drive and the SOC thresholds that determine regenerative braking, respectively; T bat T is the motor braking torque allowed by the maximum charging power of the battery. max T represents the maximum braking output torque of the monorail. Bf T Bm1 T Bm2 T Br These are the braking torques for the front axle, center axle 1, center axle 2, and rear axle, respectively; T pfT pm1 T pm2 T pr These are the mechanical braking torques for the front axle, center axle 1, center axle 2, and rear axle, respectively; T d_req This is the torque required for the vehicle's drive. V rel V represents the actual speed of the monorail crane. min This is the minimum speed for a monorail crane; T pf_max T pm1__max T pm2_max T pr_max This is the maximum output torque for mechanical braking.

[0077] The execution unit 16 includes a clamping force device 1601, a braking device 1602, and a drive device 1603. The control method is as follows: The system first collects real-time vehicle driving status data, such as vehicle speed, acceleration, operating handle opening information, and battery SOC value. When the operating handle 1402 opening information is collected, the control system enters the drive mode, optimizes the torque distribution of the inter-axle drive device 1603 according to the requested drive torque, and judges the battery SOC value at this time. If it is greater than the SOC threshold that allows the vehicle to drive, the required drive torque is calculated and each drive device 1603 is driven; otherwise, the drive force is zero. When the operating handle 1402 opening information is not collected, it judges whether the battery SOC is greater than the maximum value. If it is, the braking device 1602 applies mechanical braking; if it is not, it further judges whether the vehicle speed is greater than the minimum limit. If it is, the braking device 1602 applies electric braking to recover vehicle energy; otherwise, the braking device 1602 applies mechanical braking. If the main zero-control handle 1401 is determined to have reached the braking threshold, braking mode is activated. When the emergency braking limit is exceeded, mechanical braking is prioritized to ensure braking efficiency and rapid response. Additionally, when the vehicle speed is low or the battery charge is at its maximum, regenerative braking is not suitable, and mechanical braking is used. When the vehicle speed exceeds the minimum limit, the battery SOC value is within the maximum limit, and the braking intensity is medium to low, only the motor participates in braking. The inter-axle torque is optimized and distributed based on the braking torque requested by the main zero-control handle 1401 at this time, improving the regenerative braking rate. If the regenerative braking torque control is insufficient, mechanical braking is activated for combined braking.

[0078] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0079] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A distributed permanent magnet eight-drive electric monorail crane driving control method, characterized in that, The control method comprises the following steps: The maximum and rated rotating speeds of the permanent magnet motor are calculated based on the structural parameters and speed sensor sensing data of the eight-drive electric monorail crane, the structural parameters and speed sensor sensing data including the speed reduction ratio, drive wheel radius and speed information; then the total demand power, total demand torque of the vehicle drive system and the torque required by each drive system permanent magnet motor are accurately calculated by the vehicle controller after processing the collected personnel control information, speed and acceleration information by the control processing unit central processor after transmission through the vehicle CAN bus; Based on the sensed speed and battery SOC condition, combined with the output torque collected by the motor torque sensor, the torque optimization distribution mathematical model is established in the control processing unit to determine the distribution coefficient of each drive part and ensure the rationality of the torque distribution of each drive part, with the total efficiency of the vehicle drive system as the objective function and the torque distribution coefficient of each axis as the variable; Based on the current speed, output torque and battery SOC information, the torque optimization distribution mathematical model is established to develop a multi-working condition control method with the total efficiency and energy saving of the vehicle drive system as the control target, which formulates the best driving mode for the monorail crane in different driving conditions and dynamically distributes and reasonably brakes the vehicle motor torque to ensure the accuracy of the control of each drive system; The multi-working condition control method with the total efficiency and energy saving of the vehicle drive system as the control target realizes the accurate control of the torque, and the control strategy is as follows: After collecting the operating handle opening information Driving_S, the control system enters the driving mode, the inter-axle drive device torque optimization distribution is performed according to the driving request torque, the battery SOC value is judged, if it is greater than the lower limit value SOCmin of the allowable vehicle driving SOC, the required driving torque is calculated, each drive device is driven, otherwise the driving force is zero; When no operating handle opening information Driving_S is collected, it is judged whether the battery SOC value is greater than the upper limit value SOCmax of the braking energy recovery SOC, if it is greater, the mechanical brake of the braking device is performed, if it is not greater, it is further judged whether the vehicle speed Vrel at this time is greater than the minimum vehicle speed Vmin, when it is greater, the electric brake of the braking device is performed to recover the vehicle energy, otherwise the mechanical brake of the braking device is performed. When no operation handle opening information Driving_S is collected, if it is determined that the master control handle opening exceeds the lower limit value Brake_Smin of the master control handle opening, the braking mode is entered. When the braking intensity exceeds the upper limit value Zmax of the braking intensity for determining the braking energy recovery, in order to ensure the braking efficiency and the rapid response, the mechanical braking is preferentially adopted. In addition, when the vehicle speed is lower than the lower limit value Umin of the vehicle speed for determining the braking energy recovery or the battery SOC value exceeds the upper limit value SOCmax of the SOC for determining the braking energy recovery, the motor braking energy recovery is not suitable, and the mechanical braking is adopted. When the vehicle speed exceeds the lower limit value Umin of the vehicle speed for determining the braking energy recovery, the battery SOC value is lower than the upper limit value SOCmax of the SOC for determining the braking energy recovery, and the braking intensity is lower than the upper limit value Zmax of the braking intensity for determining the braking energy recovery, only the motor is involved in braking, the inter-axle torque optimization distribution is performed according to the braking torque requested by the master control handle opening at this time, the braking energy recovery rate is improved, and if the regenerative braking torque is insufficient, the mechanical braking is controlled to work, and the combined braking is performed.

2. The distributed permanent magnet eight-drive electric monorail crane driving control method according to claim 1, characterized in that, The total demand power of the permanent magnet motor is determined by the following formula: wherein: P h1 , P h2 , P h3 are the motor power required for the maximum vehicle speed, the maximum hill climb and the acceleration time of 7.2 km / h, respectively, in kw; P max is the maximum motor power, in kw; η t is the motor efficiency; m is the mass of the vehicle, kg; f is the rolling resistance coefficient; i max is the maximum climbing gradient, %; v p is the climbing speed, km / h; δ is the rotational mass conversion coefficient; t is the acceleration time from 0 to 7.2 km / h, s; v a is the speed at the end of acceleration, km / h; v max is the maximum speed of the vehicle.

3. The distributed permanent magnet eight-drive electric monorail crane driving control method according to claim 2, characterized in that, Through the torque optimization distribution mathematical model, the distribution coefficients of the driving parts are determined by the following formula: wherein: the motor torque distribution coefficients of the front axle, the middle axle 1, the middle axle 2 and the rear axle are k f , k m1 , k m2 and k r , respectively; T f is the front axle motor torque, Nm; T m1 is the middle axle 1 motor torque, Nm; T m2 is the middle axle 2 motor torque, Nm; T r is the rear axle motor torque, Nm.

4. The distributed permanent magnet eight-drive electric monorail crane driving control method according to claim 2, characterized in that, In the total demand power of the permanent magnet motor, the torque required by the single motor is obtained by the following method: first, the motor rated power P is determined by the 15 min maximum vehicle speed h1 Then the motor rated torque is calculated as: Tn=9550P h1 / n0, n0 is the rated speed of the motor.

5. The distributed permanent magnet eight-drive electric monorail hoist driving control method according to claim 3, characterized in that, The total efficiency of the vehicle driving system and the braking system is obtained by the following calculation formula: The total efficiency of the vehicle driving system in the driving mode is: In the formula: T req T is the demand torque of the whole vehicle, Nm; n is the motor speed, r / min; η d Total efficiency function of the permanent magnet motor drive system The total efficiency of the vehicle braking system in the braking mode is: The total efficiency of the vehicle driving system in the driving mode is: The total efficiency of the vehicle braking system in the braking mode is:

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