Segmented braking method for linear permanent magnet eddy current brake device

Abstract

This invention discloses a segmented braking method for a linear permanent magnet eddy current braking device. Step 1: Place the working section of the brake on the linear segment of the brake working curve of the equipment; Step 2: Divide the entire braking section into N segments, let it be N segments; let the proportional coefficients be K1, K2, K3...Kn, and satisfy K1<K2<K3...<Kn; Step 3: When the braking section is N segments of equal distance; the piecewise function of the end braking speed V(tn) function can be obtained; Step 4: Obtain the initial conditions of the equipment, including the initial velocity V(0), the total braking distance S, the braking end speed V(t), and the total weight m after the passenger stacked frame; Step 5: Substitute the total weight m after the passenger stacked frame, the initial velocity V(0), and the braking end speed V(tn) into the end formula of the piecewise function of the V(tn) function to obtain the range of K1+K2+Kn; since it is necessary to satisfy K1<K2<K3...<Kn, obtain the range of K values ​​for each braking section; Step 6: Based on the obtained range of K values ​​for each segment, select the K value for each segment, and adjust the thickness of the track aluminum plate or replace the track material according to the K value of each segment.

Description

Technical Field

[0001] This invention relates to a segmented braking method for a linear permanent magnet eddy current braking device. Background Technology

[0002] A linear permanent magnet eddy current brake is a device that uses the eddy current effect to generate braking force. It is typically used in applications requiring braking and is usually passive. Its basic principle is explained as follows: For a metallic conductor, a changing external magnetic field induces eddy currents in the metal, which in turn generate a magnetic field opposite to the applied magnetic field. This creates a repulsive magnetic force, thus achieving a braking effect.

[0003] In amusement rides or similar scenarios, the current braking methods are costly; and the existing structures exhibit significant differences in braking acceleration when faced with passengers of varying weights, resulting in a poor passenger experience. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a segmented braking method for a linear permanent magnet eddy current braking device that offers low construction costs and excellent braking performance.

[0005] The technical solution for implementing the present invention is as follows:

[0006] A segmented braking method for a linear permanent magnet eddy current braking device: Step 1, place the working segment of the brake on the linear segment of the equipment brake working curve;

[0007] Step 2: Divide the entire braking section into N segments, let them be 1, 2, 3...N; let the proportional coefficients be K1, K2, K3...Kn, and satisfy K1 < K2 < K3... < Kn;

[0008] Step 3: When the braking segment consists of N equally spaced segments, the piecewise function of the final braking speed V(tn) can be obtained:

[0009] Step 4: Obtain the initial conditions of the equipment, including the initial velocity V(0), total braking distance S, braking end velocity V(t), and total weight m after passenger stacking frame; Step 5: Substitute the total weight m after passenger stacking frame, initial velocity V(0), and braking end velocity V(tn) into the end formula of the piecewise function of the V(tn) function in Step 3 to obtain the range of K1+K2+K3+Kn; Since K1<K2<K3……<Kn needs to be satisfied, the range of K values ​​for each braking segment when using a piecewise design can be obtained;

[0010] Step 6: Based on the range of K values ​​obtained in Step 5, select the K value for each segment, and adjust the thickness of the track aluminum plate or replace the track material according to the K value of each segment.

[0011] 2. The segmented braking method of a linear permanent magnet eddy current braking device according to claim 1, characterized in that the segmented function of the end braking speed V(tn) function in step 3 is:

[0012]

[0013] Where K is the proportionality coefficient, m is the weight, t is the braking time, V(0) is the initial velocity, and V(tn) is the final braking velocity.

[0014] This invention introduces a segmented braking method for a linear permanent magnet eddy current braking device. The invention adjusts the thickness of the track aluminum plate or replaces the track material by obtaining the K value of each segment after the braking segment is divided. Since only the thickness of the track aluminum plate needs to be adjusted or the track material needs to be replaced, the cost is low and the operation is convenient. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the relationship between braking force and speed according to the present invention;

[0016] Figure 2 This is a schematic diagram of the relationship between speed and braking acceleration during the braking process of the present invention;

[0017] Figure 3 This is a schematic diagram of the speed and acceleration curves of a passenger with a 75kg load under the condition that the K value is not segmented, according to the present invention;

[0018] Figure 4 This is a schematic diagram of the velocity and acceleration curves of a 125kg passenger under the segmented K-value condition according to the present invention;

[0019] Figure 5 This is a schematic diagram illustrating the velocity and acceleration curves of a 75kg passenger under segmented K-value conditions according to the present invention. Detailed Implementation

[0020] 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 only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] See Figure 1The diagram illustrates the structure of this application. Example 1: Assuming the trolley on the slide rail weighs 50 kg, the minimum passenger weight is 25 kg, and the maximum passenger weight is 100 kg, the initial speed before braking is 20 m / s. The requirement is to reduce the speed to less than 0.5 m / s within a 30 m range, considering comfort. Furthermore, the instantaneous braking acceleration throughout the entire process should be ≤1.5G.

[0022] Given the input braking acceleration and braking distance requirements, first calculate the required braking force. It is known that the required average braking acceleration a ≥ 6.7 m / s². The corresponding minimum average braking force requirement is F = 150 kg * 6.7 m / s² = 837.5 Nm. Furthermore, according to the permanent magnet eddy current braking theory, the braking force is related to the speed of motion but independent of the vehicle's weight. A typical relationship between braking force and speed is as follows: Figure 1 As shown, the braking force increases almost linearly as the speed rises from zero, then the increase tends to level off, and after reaching a peak, it slowly decreases.

[0023] However, since braking force is only related to speed and not to load, it is known that the braking force experienced by tourists at the beginning of braking would be relatively large. Furthermore, due to the varying weights of tourists, smaller loads would experience larger braking accelerations. Therefore, this non-segmented braking method cannot be directly adopted. The relationship curve between speed and braking acceleration during braking is shown below. Figure 2 .

[0024] Now assume there are three passengers of different weights, whose total weight after stacking the frame is 75kg / 100kg / 125kg respectively. The design uses three-stage braking, and the braking force relationship satisfies:

[0025]

[0026] (F1 / F2 / F3 are in N; V(t) is in m / s; k1 / k2 / k3 are in N·s / m)

[0027] Furthermore, with an initial velocity of V(0) = 20 m / s, the total braking distance S must be ≤ 30 m, and the final braking velocity must be ≤ 1 m / s.

[0028] F = ma

[0029]

[0030]

[0031]

[0032] Solving the above first-order linear equation, we can see that... From V(0) = 20 m / s, we can know Furthermore, since the function is set to three equally spaced segments, each with a length of 10m, the V(t) function is a piecewise function.

[0033]

[0034] Let the velocities at the endpoints k1 / k2 / k3 be V(t1), V(t2), and V(t3).

[0035]

[0036] The condition for a piecewise function to hold is that V(t1), V(t2), and V(t3) are all greater than 0. From t1 to t3, if any of the speeds is less than 0, the function will stop at the corresponding braking point.

[0037] Based on the initial conditions, a 125kg mass needs to be decelerated from 20m / s to below 1m / s within 30m. Assuming the braking segment is not segmented, we have K1 = K2 = K3. Substituting K1 = K2 = K3 into the final formula of the piecewise function... We can obtain K ≥ (1-0.05)*250 / 3, which means K ≤ -79.1666. Therefore, we need to adjust the value of K to K ≤ -80. Furthermore, when K is -80, the braking acceleration felt by the passenger is minimized. With k = 74, the speed and acceleration curves for a passenger with a 75kg load are as follows... Figure 3 As shown; according to Figure 3 It is clear that the design meets the requirements for heavy passengers, but not for light passengers.

[0038] Therefore, the above problems are solved by segmenting the braking process. Specifically, the working segment of the brake can be placed within the linear segment of the brake's operating curve. In other words, it can be equivalently considered that within the operating speed range, the braking force and speed have a nearly linear relationship, as expressed by F = KV (where F is the braking force, K is the proportional coefficient, and V is the speed).

[0039] The entire braking segment is divided into N segments. In this embodiment 1, the entire braking segment is divided into three equally spaced segments (K1, K2, K3). The proportional coefficients are designed to be K1, K2, and K3 respectively, satisfying K1 < K2 < K3. This achieves the following effect: a lighter passenger experiences a greater braking acceleration in segment K1 than a heavier passenger, resulting in a greater speed reduction after segment K1. Consequently, the lighter passenger's initial speed in segment K2 is lower, meaning the braking acceleration in segment K2 is also lower. After the three deceleration segments, the total braking distance for the heaviest and lightest passengers can be made closer, meaning the average braking acceleration is at a comparable level, thus optimizing the passenger's braking experience. Simultaneously, this design also makes the braking force experienced by passengers of a single weight smoother throughout the entire process.

[0040] Specifically,

[0041] The calculation method for the K value of each segment is as follows: Based on the initial conditions, it is now necessary to decelerate the 125kg mass from 20m / s to below 1m / s within 30m; substitute the mass of 125kg and the final velocity of 1m / s into the final formula of the piecewise function. From this, we can obtain K1+K2+K3≥250*0.95; and since the segmented design proportional coefficients satisfy K1<K2<K3, the ranges of K1, K2, and K3 can be estimated. In this embodiment, values ​​are taken within the estimated range, where K1=55, K2=85, and K3=120; at this time, the speed and acceleration curves of a 125kg passenger are as follows. Figure 4 The speed and acceleration curves of a 75kg passenger are as follows: Figure 5 ;according to Figure 4 and Figure 5 It can be seen that the design requirements have been met.

[0042] Because changing the thickness of the brake plate in an eddy current brake affects the braking force, and because for this braking system, after other parameters are fixed, the aluminum plate thickness alone has a functional relationship with the K value. For example, an aluminum plate thickness of 5mm corresponds to a K value of 100, and an aluminum plate thickness of 7mm corresponds to a K value of 130. This is roughly how it works, determined through electromagnetic design. Specific design methods for changing the K value include, but are not limited to: adjusting the thickness of the track aluminum plate; adjusting the gap between the track and the permanent magnet; changing the track material, etc.

Claims

1. A segmented braking method for a linear permanent magnet eddy current braking device: Step 1, placing the working segment of the brake on the linear segment of the equipment brake working curve; Step 2: Divide the entire braking section into N segments, let's say 1, 2, 3...N; let the proportional coefficient be... , (i=1, 2, 3........n), and satisfy < < ... ; Step 3: When the braking segment consists of N equally spaced segments, the piecewise function of the final braking speed V(tn) can be obtained: The piecewise function of the terminal braking speed V(tn) is as follows: .................... Where m is the weight, t is the braking time, V(0) is the initial velocity, and V(tn) is the final braking velocity; Step 4: Obtain the initial conditions of the equipment, including the initial velocity V(0), total braking distance S, braking end velocity V(t), and the total weight m of the passenger stacked frame; Step 5: Substitute the total weight m of the passenger-stacked frame, the initial velocity V(0), and the final braking velocity V(tn) into the final formula of the piecewise function of the V(tn) function in Step 3 to obtain the final value. + + + The range; because it needs to meet < < ... Therefore, the braking force of each braking segment when a segmented design is adopted can be obtained. Scope; Step 6: Based on each segment obtained in Step 5 The range, select each segment According to each paragraph Adjust the thickness of the aluminum plate on the track or replace the track material.

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